Appendix 1: DRAFT Literature Review of the comparative
effectiveness of vegetated buffers in trapping pesticides,
sediments and nutrients in runoff from agricultural lands
For the report: Comparative effectiveness of community
drainage schemes and EVTAs in trapping PSII Herbicides from
sugar cane farms
Prepared by Frances Alexander, Amy Basnett, Jane Waterhouse and Melany Ginders
Australian Centre for Tropical Freshwater Research, James Cook University, Townsville, 4811
1
Reference
Arora, K., S.K.
Mickelson, J.L. Baker,
D.P. Tierney, C.J.
Peters. 1996. Herbicide
retention by vegetative
buffer strips from runoff
under natural rainfall.
American Society of
Agricultural Engineers.
39(6): 2155-2162
(Arora et al. 1996)
Arora, K., S.K.
Mickelson, J.L. Baker.
2003. Effectiveness of
vegetated buffer strips
in reducing pesticide
transport in simulated
runoff. American
Society of Agricultural
Engineers. 46(3): 635644
Experimental design
- 2 yr study
- source area 0.41ha (mainly Canisteo
silty clay loam soil), average slope 3%
- fall chisel-plowed, spring disked and
planted to corn
- atrazine (2.12kg/ha), metolachlor
(2.80kg/ha) and cyanazine (3.36kg/ha)
applied to source area ea spring (1993,
1994)
- 6 buffer strips 1.52m wide x 20.12m
long isolated with metal borders
downslope of source area in well
established bromegrass (Bromus
intermis)
- three replications of two drainage to
buffer area ratio treatments of 15:1 and
30:1
- looked at vegetated buffer strip
performance in reducing atrazine,
metolachlor, chlorpyrifos in relation to
drainage area to buffer strip area ratio.
- 6 buffer strips 1.52m wide x 20.12m
long = three reps of two inflow rates of
15:1 and 30:1
- simulated runoff mixed w pesticidetreated soil distributed onto strips
Hydrology/climatic conditions/location
- natural rainfall
- for event 6, storm had 23.1mm rain falling on 0.41ha
source area, 2.3mm ran off.
- 25min interval between start of rain and start of runoff.
- roughly 10min travel time for inflow to reach end of
20.1m buffer strips.
- travel times through strips different for each runoff
event ranging 6-13min.- for 15:1 & 30:1 area ratios for
E6, ave. percent infiltration of mixture of runoff and rain
were 73.6% and 64.9%
- simulated rainfall
- conducted in July 1995
- prior to runoff simulation, applied 25mm simulated
rainfall in 30min using a sprinkler system
- water pumped at a variable rate first inc then dec.
- water to simulate runoff pumped into an 800L tank,
total water pumped into tank equivalent to a runoff
event of 10.7mm.
- soil and pesticide added to tank at a rate of 100mg of
ea. pesticide per 1kg of soil
Results
- herbicide retention dependent on antecedent moisture
conditions of strips
- retentions ranged from: Atrazine: 11% to 100%, Metolachlor:
16%-100%, Cyanazine: 8%-100%
- outflow concentrations less than inflow conc. For all three
herbicides
- infiltration the key process for herbicide retention by the
buffer strips
- herb retention by sed. deposition in strip represented 5% of
herbicide retention.
- buffer strips had 40-100% sediment retention therefore
effective for retaining strongly adsorbed herbicides.
- see p 2159-21690 for details
- for E6 percent herbicide retained within strips was 58,73 and
69 averaged for both area ratios or the three herbicides
respectively
- infiltration for 15:1 averaged 38.8% of inflow volume, 30.4%
for 30:1.
- concentrations of atrazine and metolachlor associated w sed
outflows from strips were larger than respective inflow
concentrations, chlorpyrifos had opposite results.
- concentrations in runoff for atrazine and metolachlor in
outflow smaller than inflow concentrations, results opposite for
chlorpyrifos.
- 15:1 retained average of 52.5% of total atrazine input,
54.4% metolachlor, 83.1% chlorpyrifos
2
Reference
(Arora et al. 2003)
Experimental design
Arora, K., S.K.
Mickelson, M.J.
Helmers and J.L. Baker.
2010. Review of
pesticide retention
processes occurring in
buffer strips receiving
agricultural runoff.
Journal of the American
Water Resources
Association. FIX
- study (USA) looking at retention of
pesticides in buffer strips in runoff and
sediment.
- looked at data from other papers: 17
natural rainfall studies and 23 simulated
rainfall/runoff/irrigation studies, used
359 data points.
- only represents average or reported
data and doesn‟t take experimental
error of different studies into account
- * could be useful in relation to sorption
of particular pesticides used in Babinda
Asumussen, L.E., A.W.
White, E.W. Hauser and
J.M. Sheridan. 1977.
Reduction of 2,4-D load
in surface runoff down a
- Plots were setup with adjacent
grassed waterways (24.4m).
- An application of 2,4-D alkanolamine
salt (0.56 kg/ha) was applied by hand
sprayer.
Hydrology/climatic conditions/location
- study represents natural rainfall even in which rain
stopped by the time runoff from the field enters the
buffer strip
- inflow volume was 15.8cm into 15:1 treatment, 31.5cm
into 30:1 treatment (same for all three reps of tow area
ratio buffer strips)
- mean outflow 9.7cm for 15:1 treatments, 21.9cm for
30:1 treatment
-average time diff between flow to enter buffer and
appear as outflow downstream was 13.3min and 14min
for 15:1 and 30:1 treatments respectively
- Simulated rainfall: 25.4cm/hr for half an hour.
-Naturally occurring rainfall: 2.5cm/day (based on one
day of recorded rainfall).
-Cowarts loamy sand soil type.
-Study carried out in Tifton, Georgia.
Results
- 30:1 = 46.8% atrazine, 48.1% metolachlor, 76.9%
chlorpyrifos.
- no significant difference between 15:1 and 30:1 buffer strips
for retention of any of the pesticides. Study suggests more
replicates and or larger ratio treatments
- when averaged for both buffer strips 15: and 30:1, = retention
49.7% atrazine, 51.2% metolachlor, 80% chlorpyrifos
- most of retention for atrazine and metolachlor through
infiltration, mostly through sediment deposition for chlorpyrifos
- calculated that buffer strips would retain 45% of weak to
moderately sorbed pesticides and 70% strongly sorbed
pesticides
- * note that pesticide mass retention info presented is an
average across several studies w different experimental
setups therefore application to field studies should be
examined
- for strongly sorbed pesticides, average of 20% of loss from
source area with runoff occurs in runoff water remaining 80%
occurs with runoff sediment
- for moderately sorbed pesticides, average loss is 80% with
runoff water and 20% with runoff sediment
- almost 95-100% of total loss of weakly sorbed pesticides
occurs with runoff of water.
- pesticide retention for weakly sorbed pesticides from natural
and simulated studies averaged 61%, 63% (moderately
sorbed) and 76% (strongly sorbed)
- MUST look at pages 634-640 of this document for a table
summary of studies looking at pesticide retention.
- The „dry‟ system retained more water in the plot resulting in
less run-off entering and exiting the waterway compared to the
„wet‟ system which can be attributed to soil-water saturation.
-Most of the sediment was retained in the waterway of both
„dry‟ and „wet‟ systems.
3
Reference
grassed
waterway.
Journal
of
Environmental Quality.
6(2): 159-162
(Asmussen et al. 1977)
Experimental design
-Samples measured at 6 equal intervals
between and in addition to start and end
samples of grassed waterway.
-The objective of this study was to
determine change in herbicide
concentration and sediment
concentration with distance/time.
- Measurements were taken from two
treatments: a) dry soil conditions and b)
wet soil conditions (saturated).
-looked at grassed waterways
decreasing 2,4-D in surface runoff
- corn (Zea mays L.) plots treated w 2,4D (0.56kg/ha)
- simulated rain directed through a
24.4m long grassed waterway
Baker, J.T. and S.K.
Mickelson.
1994.
Technology and best
management practices
for minimizing herbicide
runoff.
Weed
Technology. 8(4): 862869
(Baker and Mickelson
1994)
Balderacchi, M., G.
Alavi, E. Capri, A.
Vicari, C. Accinelli, N.
Jarvis. 2002. Losses of
atrazine, metolachlor,
prosulfrun
and
triasulfron in subsurface
drain
water.
II.
Simulation
results.
Agronomie. 22(4): 413425.
Barling RD, Moore ID
(1994) Role of buffer
strips in management of
- not a study but talks about factors
affecting herbicide retention, buffer
strips, filter strips
- „ Limited data exist on the effects of
buffer strips in reducing the transport of
pollutants, particularly for herbicides‟
Hydrology/climatic conditions/location
- *only have abstract
- applied MACRO model to predict
losses of atrazine, metolachlor and
prosulfron in subsurface drain water in
experimental fields in Po Valley,
Cadriano and Carpi (Italy).
- study in march 1996 to Feb. 1997
-Model the performance of buffer strips.
Results
-Only 2.5% of herbicide was removed from the „dry‟ plot and
72% of this portion was contained within the waterway. The
„wet‟ plot was less effective at retaining the herbicide with
10.3% being removed and 69% of removed herbicide was
retained by the water way.
-In a natural scenario it is indicated that herbicide take up of a
vegetative waterway would depend on the waterways ability to
become saturated by water which is dependent on previous
rainfall events.
- if can get the full paper, should give results of the
experiment, abstract only gives accuracy of model predictions
-Australia (various studies).
-Buffer strips are most effective when the flow is shallow (nonsubmerged), slow, and enters the buffer strip uniformly along
its length.
4
Reference
waterway pollution: a
review. Environmental
Management 18, 543558.
(Blankenberg
Braserud 2003)
and
Blankenberg, A.B., B,
Braskerud, K. Haarstad.
2006.
Pesticide
retention in two small
constructed wetlands:
treating
non-point
source pollution from
agricultural
runoff.
International Journal of
Environmental
Analytical Chemistry.
86(3-4): 225-231
Experimental design
Hydrology/climatic conditions/location
Results
-Sediment trapping performance decreases as the sediment
particle size decreases (nutrients are often preferentially
attached to fin sediment). Buffer strips as a result are more
effective at retaining sediments than nutrients.
- constructed wetland in Norway (Lier,
40km south of Oslow) covered 0.38% of
watershed surface area (large for
Norway)
- wetland is 1200m2 and receives water
from a 0,8km2 large catchment area.
- catchment area includes horticulture
(0,2km2) forest (o,15km2) grain
cultivation (0,35km2) and residential
area (0,1km2)
- water enters through 2 pipelines from former streams
along with several drainage-pipes and flows through a
sedimentation pond, course particles and aggregates
removed from the water phase.
- keep runoff natural or gravity fed (not pumped)
- water enters experimental wetland, is distributed
through a constructed vegetation filter into 8 parallel
wetland compartments, each aprox 3m wide, 40m long.
- individual v notch in inlet secures same input of water
to all compartments (compartment 4 is control)
- a constructed wetland receiving 13 pesticides removed
between 0 and 67% of pesticide Concentrations (Braskerud
and Haarstad 2003 * I can‟t access this article).
- Hydraulic load rate (HLR) is runoff (m3/day) divided by
wetland surface area (m2). Usually retention inc. as
HLR dec because of a longer detention time.
- Grautholen: average HLR for 19 month period was
1.8m day-1, for period of investigation (may to sep) HLR
was 0.5 and 0.4m day-1 for 2000 and 2001. Runoff
characterized by larger single runoff events in first year
than in second.
- Lier: average HLR may to sep. 2003 was 0.9m day-1,
hydraulic load peaks in May and July. HLR higher in
Lier than Grathuolen (expected because of larger
surface area)
- all applied pesticides round in streams w highest
concentrations immediately after spraying
- pesticides added to watersheds dec on average through
whole sampling periods from 3% to 67%.
- retention inc with size of wetland
- in many cases CWs reduced peak conc. to values regarded
as non-toxic for aquatic life
- paper presents results of measurements in samples
collected between sedimentation pond and outlet
delete these? No results!
- four herbicides 3 fungicides applied
on arable soil on two watersheds in
Norway. (Linuron, Metamitron,
Metribuzin, Propachlor, (herbicides)
Propiconazole, Fenpropimorph,
Metalaxyl (fungicides))
- two constructed wetlands in western
and eastern Norway.
- CWs cover 0.15% and 0.4% of
watershed respectively
- watershed in west Norway
„Grautholen‟ (45km south of
stravanger): 0.22km2, wetland is 100m
long w surface area of 840m2.
-depths are 0.5m in a, 0-0.3m in b, 0m
in c, 0-0.3m in d (shallower than
original because of sedimentation) in
may 2000 to dec 2001.
- entire wetland covered with vegetation
mainly Sparganium erectum,
Phragmites austrais, Phalaris
arundinacea and „Trin. Ex Steud.
(common weed) in wetland filters.
- In overflow zones, S. erectum, Myostis
- amount of pesticides removed varied from 3 to 67%
- no days between spraying and precipitation important for
pesticide retention.
5
Reference
Borah, D.K., M. Bera
and S. Shaw. 2003.
Water,
sediment,
nutrient and pesticide
measurements in an
agricultural watershed
in Illinois during storm
events.
American
Society of Agricultural
Engineers. 46(3): 657674.
(Borah et al. 2003)
Experimental design
scorpioides, Urtica dioica and various
grasses dominated
- vegetation cover always exceeded
70%
- wetland in east Norway „Lier‟ (40km
south of Oslo): 1200m2, receives water
from 0.8km2 large catchment, wetland
built in 2001
- most pesticides added once/yr in
grautholen at end of may 2000 and
2001. Metribuzin added only in 2000.
Propiconazole and fenpropimorph
added twice per season with additional
spraying in mid July.
- in Lier, pesticides added late June
2003 High doses of pesticides sprayed
on an upstream area (0.1-0.2ha) near
the CWs
- monitored flow and concentration of
atrazine and metolachlor and alachlor
(and suspended seds. Nitrate and
phosphate) during spring in 1998, 1999,
during storm events at a tributary station
(Big Ditch- drains 98km2 of sub
watershed of lake decatur watershed)
and two main-stem stations (Fisher and
Mahomet- drain 622km2 and 932km2 of
upper Sangamon river or lake Decatur
watershed) of upper Sangamon River,
east central Illinois.
- rainfall data collected from 6 rainfall
stations- one at big ditch during 1998
and 1999 and five through upper
Sangamon river watershed above
Mahomet during 1999
- soil mostly silt loam and silty clay
loam, poorly drained, high organic
content
- watershed has extensive tile drainage
Hydrology/climatic conditions/location
Results
- each station showed positive relationships between
phosphate, atrazine and metolachlor concentrations with water
discharge.
-figure 8 shows cumulative rainfall at stations along with
hourly water discharges at big ditch, fisher and
Mahomet during 1999 monitoring period
- the six stations recorded noticeably variable rainfall
amounts especially in western stations vs. eastern
stations. Only intense storm recorded in all gages was
15-16 April 1999 (approx 76mm) fig 8a p666 for more
details if needed
- BIG DITCH STATION, SPRING STORMS 1998:
- highest conc. (33 and 28ug/L observed for atrazine and
metolachlor respectively in early may 1998 (fig6), middle of
corn planting and herb application in northern half of Illinois
- analyses for alachlor didn‟t detect the herbicide in water
samples
6
Reference
Borges, A.C.,…. Please
check, not sure which
Experimental design
- looked at feasibility of CW‟s for
mitigation of pesticide runoff.
Hydrology/climatic conditions/location
- cells had varying bottom inclinations and total volumes
A (0.5% and 5.70m3), C(1.0% and 4.40m3), D(1.5%
Results
- DATA COLLECTED AT STATIONS ABOVE MAHOMET
DURING 1999 SPRING STORMS
- only monitored atrazine due to budget constraints. Atrazine
showed similar pattern but higher concentration with respect to
metolachlor in big ditch during 1998 (fig 6)
- atrazine followed graph similarly to sediment and phosphate.
- atrazine conc. 9ug/L during April high flows and as high as
18ug/L during june storms (fig 10b)
- high conc. in early June maybe due to timing of herbicide
application (mostly at planting between 3rd wk in April and until
mid may) (Roberts 2002)
- atrazine concentration fitted similar power function
relationships w water discharge as shown in figure 7a
- at Mahomet station: max atrazine concentration during April
storm was aprox 6ug/L. on June 2nd concentration inc to
11ug/L
- at fisher station, peak atrazine during June storm was 28ug/L
and April storm concentration was 6ug/L
- errors in sampling may be one of many reasons for such a
high single-point atrazine conc. In fisher
CONCLUSIONS
- atrazine concentrations showed reasonable relationships
showed reasonable relationships with water discharges at all
stations most of the time
- metolachlor showed good relationships with water discharge
during certain months in 1998
- 39% of ametryn initially added was removed transferred or
transformed, operating with a HRT of 3.8d
7
Reference
are first and which are
last names. 2009.
Water SA. 35(4).
Accessed 11/8/10.
(Available:
http://www.wrc.org.za)
(Borges et al. 2009)
Experimental design
- CW‟s were submitted to continuous
ametryn addition and evaluated during
an 11wk period
- ametryn not added to one cell= control
- CW contained macrophyte Typha
latifolia
Bouldin, J.L., J. L.
Farris, M.T. Moore, S.
Smith
Jr.,
W.W.
Stephens, C.M. Cooper
. 2005. Evaluated fate
and effects of atrazine
and lambda-cyhalothrin
in
vegetated
and
unvegetated
microcosms.
Environmental
Toxicology. 20(5): 287298.
(Bouldin et al. 2005)
- can use constructed wetlands as BMP.
- application of atrazine and lambdacyhalothrin (pyrethroid insecticide) to
vegetated and unvegetated microcosms
to measure fate and effects of
pesticides applied at suggested field
application rates.
- focused on monocultures of Ludwigia
peploides and Juncus effusus
- vegetative cover was aprox 95%
sediment and water depths aprox 10
and 8cm respectively.
- treatments were control (no pesticide
application), atrazine at 2.23kg a.i/ha,
lambda-cyhalthrin at 0.028kg a.i./ha and
atrazine and lambda-cy. combined at
the same app rates as those in each
vegetated monoculture, as well as in
each of two sediments with no
vegetation
- * paper talks about use of plants for
pesticide mitigation
Hydrology/climatic conditions/location
and 3.30m3), B(control, 1.0% and 4.40m3)
- hydraulic retention time (HRT): A (0.77m3d-1), C
(0.6m3d-1), D (0.45m3d-1)* actual HRT values were
superior to 3.5d initially proposed
Results
- concluded that constructed wetlands capable of mitigating
water contaminated with ametryn acting a buffer filters btw
emission sources and downstream superficial waterbodies
- *** look at table 2 for summaries of other studies
- the average influent contents were significantly different from
the average effluent contents
- macrophytes play important role in absorption of ametryn
- 12% to 24% of water was lost
- amount of ametryn detected in CW effluents estimated to be
61% of initially added amount
- CWs with different slope inclinations did not present
significant performance differences.
- presence of macrophytes and a hydrologic regime aid in the
transfer and transformation of pesticides associated with
agricultural runoff
- pesticide sorption evident through concentrations of atrazine
and lambda-cyhalothrin in plant tissues high as 2461.4ug/kg
(Ludwigia peploides) and 86.5ug/kg (Juncus effusus )
- based on toxicity in midge larvae Chironomus tentans,
suggest that effective mitigation of pesticides from runoff can
depend on macrophyte contact and vegetative attributes
associated with ditches
- aqueous conc. of atrazine highest after 28 days and after
3hrs for lambda-cy.
- atrazine of 112.94ug/L measured in pesticide combinationamended microcosm (table III)
- lambda0cy of 28.282ug/L in the J. effuses microcosm
exposed to only lambda-cy.
- atrazine concentrations only detectable in water sampled
after 28days, and 56 days in microcosms amended with only
atrazine, concentrations were detected in 3-24hrs in water
from microcosms amended with pesticide combination
- see p 490 for more results that may or may not be important
about pesticide peaks in plants/ interactions
8
Reference
Boutron, O., Margoum,
C., Chovelon, J-M.,
Guillemain, C., and
Gouy, V. In press.
Effect
of
the
submergence, the bed
form geometry and the
speed of the surface
Experimental design
-The role of ditch bed substrates at
adsorption of pesticides was
investigated through looking at three
parameters; speed of surface water
flow, submergence and geometrical
characteristics of the bed forms).
-Pesticides: isoproturon, diuron,
tebuconazole and azoxystrobin.
Hydrology/climatic conditions/location
Laboratory study, France.
Results
-The transfer of pesticides from surface water flow into bed
substrate is favoured by influence of increased surface water
speed (7m/s) and increased submergence.
-Extrapolation of flume data over a distance of several
hundred meters suggests that an interesting possibility for
improving the mitigation of pesticides in ditches would be to
increase the submergence and to favour bed forms which tend
to enhance perturbations and subsequent infiltration of the
9
Reference
water flow on the
mitigation
of
the
pesticides in agricultural
ditches.
Water
Resources Research.
Boyd, P.M., J.L. Baker,
S.K. Mickelson, S.I.
Ahmed. 2003. Pesticide
transport with surface
runoff and subsurface
drainage through a
vegetative filter strip.
American Society of
Agricultural Engineers.
46(3): 675-684.
(Boyd et al. 2003)
Experimental design
-A tilted experimental flume was used
with hemp fiberes as the natural organic
substrate.
-Two surface flow velocities were
tested: 2cm/s and 7 cm/s.
- looked at effectiveness if VFS 81%
Brome grass (Bromus inermis), 12%
bluegrass (Poa praternsis), 5%
bluegrass (Festuca arundinacea) and
2% varying species, for reducing mass
transport of atrazine, acetochlor and
chlorpyrifos with surface runoff under
natural rainfall in central Iowa.
- also measured pesticide
concentrations in water from single
subsurface drain under the plots
- tile was capped at the upslope end
stopping all tlle flow from the source
area. Only surface water infiltrating
through the VFS can enter the tile
- atrazine and acetochlor applied as
broadcast spray with 187L ha-1 water
and surfactant, chlorpyrifos banded over
the row in granular form using
insecticide hoppers on the planter
Hydrology/climatic conditions/location
Results
surface water flow.
- pesticides in surface runoff under natural rainfall
- table 2 summarises rainfall events causing runoff in
the 1999 crop season
- event E3 had the largest accumulative rainfall and
moderate rainfall intensity: 19.4mm rain in 110mins,
long duration allowed saturation of soil surface causing
the highest flow rate and yielding largest total volume of
runoff
- figures 3 and 4 show hydrographs of average inflow
and outflow rates during E3 for 15:1 and 45:1 area ratio
plots
- chlorpyrifos losses in the range of 10-40% of total loss from
source area (in arora et al 2010)
- results showed that factors affecting pesticide transport
included rainfall timing and intensity, hydrology, source to VFS
area ratios, adsorption properties of pesticides in VFS inflow
(inflow water infiltration and sed deposition had significant
effects on pesticide passage through VFS).
- sed deposition considerably higher in 15:1 area ratio plots
than 45:1 =aided in reduction of sediments adsorbed to
sediment
- reduction of atrazine and acetochlor primarily controlled by
infiltration efficiency of VFS.
- chlorpyrifos highly adsorbed to sed, therefore sed deposition
in VFS equally if not more important that infiltration for mass
removal
- atrazine and acetochlor = low to moderate adsorption and
moved primarily in runoff water
- subsurface drainage from tile line showed measurable
concentrations of moderately adsorbed herbicides in tile flow
at the time of surface runoff, but concentrations of strongly
adsorbed chlorpyrifos below detection.
- at lower flow rates, VFS can effectively reduce runoff,
sediment and pesticide transport from crop land
- concentrations of all pesticides were higher in inflow than
outflow for all events
- equal volumes
- table 6 summarises al total masses for each sampler for
event E3
- table 3 lists details of infiltration and runoff for each of
10
Reference
Experimental design
Hydrology/climatic conditions/location
the plots used in calculating the overall water budget
- the percentage of average infiltration amond was
higher for the 15:1 plots than for the 45:1 plots, however
it was not significantly different (0.05)
- table 4 gives water budget summaries averaged over
infiltrations for the 1999 runoff events
Bronnum, R., S.E.
Jorgensen, W.J. Mitsch.
Occurrence
and
degradation of Alachlor
and Nitrate.
(Bronnum et al. NA )
- purpose was to measure
concentrations of alachlor and nitrate in
inflow and outflow of Olentangy River
Wetland Research Park to investigate if
wetland is able to degrade alachlor and
see if alachlor affects the denitrification
- there are 2 wetlands but in this study,
samples taken from wetland 1 only,
which was extensively planted with
hydrophytes
- the two wetlands receive water pumped from
Olentangy River at rate proportional to water level of
the river to reflect the hydroperiod of a naturally
occurring weltand
Results
- Sediment reduction played a large part of pesticide removal
as majority of pesticide mass reductions that were statistically
different between treatments were in the sediment phase
- Sediment retention rate played an important role in pesticide
reduction in outflow and decreased with flow volume and
velocity
- table 1 shows sampling dates and averages of alachlor and
nitrate in inflow and outflow of wetland 1 in 2000
- no significant difference between alachlor concentration in
inflow and outflow
- mean concentration of inflow over all sampling days was
0.29+-0.23mg/L, outflow was 0.26+-0.24mg/L
- suggested reason for no significant difference stems from
factors such as wetland succession, retention time,
microorganism adaptability and concentration of alachlor in the
water
11
Reference
Experimental design
Hydrology/climatic conditions/location
Results
Budd, R., A. O‟Geen,
K.S.
Goh,
S.
Bondarenko and J.
Gan. 2009. Efficacy of
constructed wetlands in
pesticide removal from
tailwaters in the Central
Valley,
California.
Environmental Science
and Technology. 43:
2925-2930.
- evaluated two constructed wetlands in
the Central Valley for their performance
in removing pyrethroid and
organophosphate insecticides under
field-scale production conditions.
- water flow rates at outlet of CW1 or CW2 much
smaller than those at inlet.
- on average there was an 87% decrease from 0.071m3s-1 at the inlet to 0.009m-3-1 at the outlet for CW1 and
68% los from 0.016m3/s at inlet to 0.005m-3s-1 at outlet
for CW2
- average daily max tem was 36.1 degrees C and
relative humidity was 46% = average 068 cmd=1 loss
due to evapotranspiration
- overwhelming loss in flow thought to be because of
underground seepage
- average flow rate into CW1= 0.07m3s-1, CW2=
0.02m3s-1
- both CWs highly effective in reducing pyrethroid
concentrations in tailwater
- season-average concentration reductions ranged from 52%
to 94%
- wetlands reduced flow volume by 68-87% through
percolation and evapotransportation
- when concentration and volume reductions considered,
season-average removal of pyrethroids ranged from 9-100%.
- seasonal average of chlorpyrifos ranged from 52-61%
- wetlands less effective at removing diazinon because of its
limited sorption to sediment particles
- concentrations in outlet flow found to be significantly smaller
than those in inlet flow for both CWs for permethrin,
cypermetrhin, bifenthrin and λ-cyhalothrin
- CW1 retention time for 1st segment = 1hr, could not estimate
residence time of second segment as the bromide tracer was
diluted below detection limits
-CW2 slightly more effective at reducing pyrethroid levels from
tailwater than CW1. CW2 had long flow route with dense
vegetation and estimated residence time of 18hrs
-longer flow path and denser vegetation in CW2 appeared to
contributed to more effective retention of particles carrying
pyrethroids leading to improved removal efficiency/
- on average CW1 and CW2 showed 61% and 52% reductions
respectively of water concentration of chlorpyrifos
- outlet chlorpyrifos conc., significantly lower (=<0.05) than the
inlet concentrations or CW1 but not for CW2
(Budd et al. 2009)
12
Reference
Experimental design
Hydrology/climatic conditions/location
Results
-
Caron, E., P. Lafrance,
J.C.
Auclair,
M.
Duchemin.
2010.
Impact of grass and
grass with poplar buffer
strips on atrazine and
metolachlor losses in
surface runoff and
subsurface infiltration
from agricultural plots.
Journal
of
Environmental Quality.
39(2): 617-629.
(Caron et al. 2010)
Cheng,
S.,
Z.
Vidakovic-Cifrek,
W.
Grosse, F. Karrenbrock.
2002.
Xenobiotics
- abstract only
- 2yr study, compared impact of grass,
grass+tree buffer strips on exported
masses of atrazine, metolachlor and a
degradation product of atrazine,
desethylatrazine (DEA)
- system consisted of four replicate plots
in a three way completely randomized
design (no buffer zone, grass buffer
zone and grass+tree buffer strips
- field plots were 5m wide and 30m long
and grown in corn (tree strips also had 8
young poplars)
- over 2yrs surface runoff and
subsurface infiltration water were
collected after initial three rainfall events
after herbicide application.
- looked at removal efficiencies on
xenobiotics from polluted water in a
twin-shaped constructed wetland
consisting of a vertical chamber with the
- removal rates calculated from difference between loads at
outlet and inlet were from 95 to near 100% for pyrethroids and
68-99% for diazinon and chlorpyrifos
- presence of buffer strips dec exported masses of atrazine
and metolachlor in surface runoff.
- there was a significant reduction (40-60% in 2004, 75-90% in
2005) in total surface runoff and infiltrated water exported
masses of atrazine and metolachlor in the presence of buffer
strips.
- differing rainfall events greatly affected flow distribution and
leached herbicide concentrations
-no significant difference in capacity to reduce herbicide
exports was observed between grass and grass and trees.
- after 4 month period of application, removal efficiencies of
the applied pesticides parathion and omethoate were 100%
with no detectable parathion and omethoate in effluent.
- decontamination less efficient for applied herbicides, removal
13
Reference
removal from polluted
water
by
a
multifunctional
constructed
wetland.
Chemosphere. 48:415418.
Experimental design
crop plant Colocasia esculenta and
reverse vertical flow one with
Ischaemum aristatum var. glaucum.
Hydrology/climatic conditions/location
Results
efficiencies were 36% for 4-chloro-2-methyl-henoxyacetic acid
and 0% for dicambia.
- plots were irrigated 24h after chemical application with
a rainfall simulator
- In 1989, 53mm rainfall was applied in 1hr, in 1989,
81mm of rain was applied in 1.5hr
- table 4 shows simulated rain totals for both years
- in 1988, herbicide and rhodamine dye concentration peaks
ranged from 1 to 38ug l-1.
- In 1989 concentrations higher than 1988, alachlor and
cyanazine concentration peaks exceeding 500ug l-1 from one
tile line.
- pendimethalin found in only one sample barely above
detection limit
- in both years, herbicide and dye concentrations peaked
within 130min after the start of rainfall
rapid solute movement to the 1.2m tile depth suggests that
preferential flow is an important mechanism affecting chemical
transport through structured soils
- table 5 shows total sampling time, drainage and percentage
losses of applied herbicides in 1988
(Cheng et al. 2002)
Cullum, R.F., M.T.
Moore, S.S. Knight and
P. Rodrique. 2003
(Cullum et al. 2003)
Czapar, G.F., R.S.
Kanwar
and
R.S.
Fawcett.
1994.
Herbicide and tracer
movement to field
drainage tiles under
simulated
rainfall
conditions. Soil and
Tillage Research. 30:
19-32
(Czapar et al. 1994)
Read later
- field experiments conducted in 1988
and 1989 measuring herbicide and
tracer movement to tile lines during and
immediately after a simulated heavy
rainstorm.
- in 1988 alachlor, cyanazine and
rhodamine WT dye were applied to
4.5m2 plots directly over field drainage
tiles.
- in 1989 alachlor, cyanazine,
rhodamine wt and pendimethalin were
used.
- tile effluent sampled for 8hrs after
irrigation (see next column for details)
- table 2 shows chemicals applied in tile
drain experiment
table 6 shows sampling time, drainage and percentage losses
of applied herbicides in 1989
14
Reference
Experimental design
Hydrology/climatic conditions/location
Results
Dawson H (1997) 'Land
use practices for wet
tropical
floodplains.'
Department of Natural
Resources: Centre for
Wet Tropics Agriculture,
South Johnstone.
-Guidelines for the drainage of water or
pondage after high rainfall and is
concerned with „farm‟ level practices.
-Wet tropical floodplains, Australia
-The use of flood detention basins in sugar cane land use.
These detention areas can be used for recharging
groundwater, providing habitat and acting as low-flow nutrient
filters.
Dosskey MG (2001)
Toward
quantifying
water
pollution
abatement in response
to installing buffers on
crop
land.
Environmental
Management 28, 577598.
-Review of literature for evidence of how
much reduction in non-point source
pollution can be achieved by installing
buffers on crop land.
-Studies from various places (include U.S, France and
Finland).
-Buffers limit sediment runoff from fields; retain sediment and
sediment-bound pollutants from surface runoff.
- Abundant evidence clearly indicates that buffers can retain
pollutants from surface runoff from fields, filter surface and
groundwater runoff at field margins, stabilize eroding banks,
and contribute to processes that remove pollutants from
stream water flow.
-
Dousset,
S.,
M.
Thevenot, D. Schrak, V.
Gouy and N. Carluer.
2010. Effect of grass
cover on water and
pesticide
transport
through undisturbed soil
columns, comparison
with field study (Morcille
watershed, Beaujolais).
Environmental
Pollution. 158: 24462453
(Dousset et al. 2010)
- purpose is to assess effectiveness of
two grass covers (buffer zone and
grass-covered inter-row) to reduce
pesticide leaching
- some artificial inflows (simulating vineyard runoff
events) were replicated at three different times (T0,
T14, T28 days respectively)
- T0 contained homogeneous mixture of 5mg L-1
bromide and 100ugL-1 diuron, procymidone or
tebuconazole, simulating contaminated runoff after a
rainfall event.
- A 3.6L volume of solution was applied onto surface of
each column (176.6cm2)
- this simulated runoff corresponds to a <2yr rain event
frequency (Lacas 2005)
- the bromide-pesticide solution was applied onto the
top of each lab or outdoor soil column at a constant flow
rate of 10.2cm h-1 using a peristaltic pump.
- two additional water inflows consisting of 3.6L of water
were applied to the columns fourteen T14 and twenty
- lower amounts of pesticides leached through grass-cover soil
columns (2.7-24.3% of the initial amount) than the bare soil
columns (8.0-55.1%) in correspondence with their sorption
coefficients.
- diuron was recovered in higher amounts in leachates (8.932.2%) than tebuconazole (2.7- 12.9%) in agreement with
their sorption coefficients.
- despite having a similar sorption coefficient similar to that of
diuron, more procymidone was recovered in the leachates
(10.2-55.1%) probably due to its facilitated transport by
dissolved organic matter
15
Reference
Experimental design
Elsenbeer, H., A. West,
et
al.
(1994).
"Hydrologic pathways
and
stormflow
hydrochemistry
at
South Creek, northeast
Queensland." Journal of
Hydrology 162(1-2): 121.
(Elsenbeer et al. 1994).
-A stream and two of the connected
gully streams (one intermittent and one
ephemeral) were sampled during rainfall
events to determine the change in water
chemistry caused by over land flow.
-Water samples from each of the 3
streams were taken in synchrony over a
month and captured 2 rainfall events
and tested for physic-chemical factors.
-Comparisons were made between the
main stream and the gully streams
downstream based on how much
overland flow had occurred upstream of
sample.
-A randomized complete block design
with 3 replicates used to test 3 types of
vegetative cover (sunn Hemp, Sudex
and common oats) of known seedling
density for sediment and nutrient
capture.
-Plots were exposed to natural rain
events over a study period (spring +
early summer 2004), samples were
collected when plot run-off occurred.
- Sediment was suspended above the
plots in a known volume to be
transported into the plots during a rain
event.
-Rainfall events were modeled based on
concentration of water flow to determine
what model factors best describe the
ability of vegetative filter strips (VFS) of
various sizes, to retain water and
sediment. (Model factors include
hydrological factors: infiltration, outflow,
sediment factors: trapping efficiency of
sediment and phosphorus in particulate
Fares, A. and M. Ryder
(2006). Performance of
vegetative filters to
control loadings of
sediment and nutrients
in to surface water
bodies in a Hawaiian
watershed.
14th
International
soil
conservation
organization
conference. Marrakech,
Morocco: 1-4.
(Fares and Ryder 2006)
Fox, G. A., R. MuñozCarpena, et al. (2010).
"Influence
of
flow
concentration
on
parameter importance
and
prediction
uncertainty of pesticide
trapping by vegetative
filter strips." Journal of
Hydrology/climatic conditions/location
eight T28 after the pesticide application in order to
assess potential pesticide release from the soil.
- each inflow lasted 3h on average except for the grass
covered inter-row soil (26hrs)
-Study sites 5km away from Babinda.
-Annual mean rainfall (1985-1992) 4241mm.
-Monthly mean rainfall for study period: 540mm.
-Inceptisols and oxisol soil types in study area.
Results
-Water that has been subjected to overland flow had varying
physico-chemical quantities compared to main stream
(upstream).
-These properties change on a temporal scale with regard to
rainfall event duration.
-The concept of „old‟ water (from main stream) and „new‟ water
(subjected to overland flow) is explored with regards to „new‟
water having obtained a signature from the overland route.
-Study site was in Hawaii.
-Volcanic soils.
-Highest daily rainfall event in study period: 23.7mm/hr
-All vegetative cover types retained suspended solids during
rainfall induced run-off events.
-Nutrient removal in run-off varied based on functional
characteristics of each plant type (e.g nitrogen fixer).
- Soils high in clay content may have a negative effct on
potential nutrient reduction (was not clear why).
-Study area in Iowa using brome and bluegrass VFS.
-Soil type was a moderately erodible Galva silty clay
loam (fine-silty, mixed, mesic, Typic Hapludoll).
-Uniform slopes (5.0-5.5%).
-Simulated rainfall: 63mm/2hr either 100% of plot area
or 10%. Plot area: 4.6m long, widths range from 0.5m20.0m
-Uniform rainfall resulted in VFS retaining more sediment and
pesticides compared to concentrated rainfall.
-Hydrological characteristics and sediment characteristics
were dominant for determining sediment reduction. For
uniform flow, soil infiltration capacity, size of VFS and particle
size were the dominant model inputs. For concentrated flow
where infiltration was limited due to flows exceeding infiltration
time, only size of VFS and particle size were dominant inputs.
-Pesticide removal was strongly determined by hydrologic and
16
Reference
Hydrology
384(1-2):
164-173.
Fox, G. A. S. and J.
George
(2009).
"Comment on “Major
Factors Influencing the
Efficacy of Vegetated
Buffers on Sediment
Trapping: A Review and
Analysis,” by Xingmei
Liu, Xuyang Zhang, and
Minghua Zhang in the
2008 37: 1667–1674."
Journal
of
Environmental Quality
38(1): 1.
Gregoire,
C.,
D.
Elsaesser, et al. (2009).
"Mitigation
of
Agricultural NonpointSource
Pesticide
Pollution in Artificial
Wetland Ecosystems–A
Review."
Climate
Change, Intercropping,
Pest
Control
and
Beneficial
Microorganisms: 293338.
Experimental design
and dissolved form and pesticide
factors: soil type and potential soil
carbon sorption).
-Field methods to provide model
outcomes involved VFS of various sizes
with simulated rainfall that contained
sediment and pesticides (chlorpyrifos
and atrazine) and two different tests;
rainfall simulation on 100% of VFS and
10% of VFS.
Hydrology/climatic conditions/location
Results
sediment characteristics as opposed to pesticide inputs due to
the importance of infiltration in uniform flows and sediment
size in concentrated flow. Clay content in the soil was also an
important factor.
-Highlights the significance a rainfall event has on determining
VFS efficiency/success.
-Disagrees with Liu et al‟s (2008) approach to modeling
sediment and contaminant removal by vegetated buffer zones
based purely on physical characteristics.
-Hydrological impacts should be given relevance.
- Highlights more appropriate models used by Sabbagh et al
(2009).
-A review of artificial wetland systems
designed to reduce pesticide loads into
water bodies in Europe.
-One of the artificial wetlands discussed
is a vegetated ditch.
-Experimental ditches under natural
conditions were built in Germany.
-Experimental ditches under laboratory
conditons were constructed in France.
-mass balance of pesticide load inletoutlet is the parameter compared
between natural conditions and
laboratory conditions.
-Identifies that simulation of pesticide
dynamics must include three key
processes; water and solute transport,
adsorption-desorption and degradation.
-Natural condition vegetated ditches were in Germany
(Krottenbach, Landau), flow rate of max. 800 L/min.
Ditches made of heavy pond foil and concrete.
-Laboratory ditches were in France (Cemagref in
Antony), slope between 0.01 and 5%, 30L/sec in inlet
ditch. Soil was taken from forested buffer (includes clay,
fine silt, coarse silt, fine sand, coarse sand).
- Increasing retention time of water is key to the removal of
pesticides.
--Increased retention time must allow for degradation of
pesticide and adsorption that then follows to biological
absorption by macrophytes and further degradation of microorganisms.
-It may be necessary to artificially enhance residence time,
adsorption, absorption and degradation vectors to get optimal
pesticide/pollutant removal.
17
Reference
Grismer ME (2006)
'Vegetative filter strips
for nonpoint source
pollution control in
agriculture.'
(ANR
Publications)
Experimental design
-Design characteristics for VFS:
Slope: <5%
Width: flat-3-4.5m, slope- lots of 1.8m
strips
Vegetation: sturdy, tall perennial
grasses
Placement
Maintenance
Haarstad, K. and B.C.
Braskerud.
2003.
Pesticide retention in
the watershed and in a
small
constructed
wetland treating diffuse
pollution.
Diffuse
Pollution Conference,
Dublin.
- used herbicides propachlor, linuron
and metamitron and fungicides
propiconazole, fenpripimorph and
metribuzin and metalaxyl. Applied on
arable soil plot (watershed)
- water from 22ha watershed enters the
wetland, see paper for details about
water movement, depths, soil
composition etc of watershed and
wetland
- pesticides added once on may 26th
and may 30t for 2000 and 2001, the
same area was used for spreading the
pesticides both years
(Haarstad
Braskerud 2003)
and
Hydrology/climatic conditions/location
- study conducted in Norway, seems to be an extension
of Braskerud and Haarstad 2003 (only have abstract).
- average hydraulic load in G1 and G2 was relatively
high, 0.- and 0.5m d-1 in 2000 for G1 and G2.
Results
-The ability of VFSs to trap pesticides varies depending on the
nature of the compound and the design and maintenance of
the filter strip.
-Vegetation filter strips are better at removing pesticides such
as pyrethroids that bind to soil particles.
-The effectiveness of VFSs depend on field conditions such as
soil type, rainfall intensity, slope, micro-topography (surface
soil roughness), the infiltration capacity of the vegetated area,
the width of the strip, and the height of its plants.
-Slope and micro-topography affect overland flow velocity and
uniformity and also appear to have an effect on the ability of
VFSs to retain sediment and pollutants in runoff.
-Infiltration capacity and interflow within the VFSs influence the
fate and path of dissolved nutrients and chemicals.
-The width of VFSs determines the strips‟ sediment-removing
capacity and the amount of time the pollutant can be expected
to remain in soil layers where adsorption and degradation
processes are active.
- aprox 96% of applied pesticides disappeared within the
watershed, 3 remained as residuals in soil profile for a year.
- constructed wetland situated in first-order stream managed
to lower the peak concentrations significantly.
- for summer retention varied from 12 to 67% the first year, in
the second observed both loss and retention
- only a minor part of the applied pesticides leaves the
watershed
- retention processes in the watershed itself removed aprox
89% of pesticides.
- in the constructed wetland:
- less than 2% of the applied pesticides were retained in the
wetland. But wetland had an important effect in lowering the
peak pesticide concentrations that can be harmful for aquatic
18
Reference
Experimental design
Hairsine, P. (1997).
"Controlling sediment
and nutrient movement
within
catchments."
Industry
report,
Cooperative Research
Centre for Hydrology,
Melbourne.
-Project ran from 1993-1996 and part of
it looked into controlling the delivery of
sediments and nutrients in water supply
catchments through the assessment of
grass buffer strips.
-Looked at various buffer configurations,
vegetation type and inflow rates of
sediments and nutrients.
Hydrology/climatic conditions/location
-Tarago catchment (West Gippsland, Victoria).
-Flow rates: 0.07, 0.14 and 0.28 L/meter width/sec
-Filter strips 3m or 6m wide (enclosed on 2 sides)
-soil types: 1x krasnozem and 1x granite-derived loam
(Hall et al. 1972)
(Hall 1974)
Hatfield JL, Mickelson
SK, et al. (1995) Buffer
strips:
landscape
modifications to reduce
off-site
herbicide
movement. In 'Clean
water
Clean
environment - 21st
Century
Team
Agriculture - Working to
Protect
Water
-Study evaluating mechanisms of action
of buffer strips composed of a
bromegrass waterway mixture.
-Conducted under natural and simulated
rainfall.
-Herbicides: atrazine, cyanazine and
metolachlor.
-Study site: Central Iowa.
Results
life.
- average retention of pesticides was 21% for G1 and 42% for
G2 in 2000(not exactly sure what G1 and G2 are: see p103).
Retention decreased next year to 1 and 8%
- Higher retention achieved in 2000 compared to 2001 in spite
of lower average detention time in first year (aprox 7 and
10hrs for G2)
-Factors influencing filter performance were: rate of upslope
soil erosion, vegetation density and structure, water flow rate
and fineness of sediment.
-Grass filter strips are less effective at trapping phosphorus for
weakly aggregated soils.
-Vegetation which is dense and uniform in ground cover is
best.
-To reduce flow rate, make buffer zones wider.
- 80-98% total loss of atrazine with runoff water (in arora et al
2010)
- 80-98% total loss of atrazine with runoff water (in arora et al
2010)
-Reductions of up to 40% under both simulated and natural
rainfall for all three herbicides.
-The mechanism for removal from solution in runoff water was
adsorption of the herbicides in the upper 2 inches of the soil
surface.
-It is important that the water is distributed as uniformly as
possible once it enters the buffer strip.
19
Reference
Resources'.
Kansas
City, Missouri
Experimental design
Helmers MJ, Isenhart
TM, et al. (2008)
'Buffers and vegetative
filter strips.'
-A review of vegetative buffers in terms
of implementing them as policy.
-Study area: Various (U.S).
Hoffmann, C. C., C.
Kjaergaard,
et
al.
(2009).
Phosphorus
retention in riparian
buffers: review of their
efficiency,
American
Society of Agronomy.
-Field monitoring of phosphorus
retention (particulate and DRP) by
buffer strips (a review of other studies).
Hunter H, Lukacs G
(2000) 'Nutrient control
in irrigation drainage
systems using artificial
wetlands.'
-A study looking at the potential of
constructed wetlands for improving
water quality of irrigated drainage
waters in the Burdekin River Irrigation
Area.
-Performance trials were undertaken to
quantify changes in concentrations and
loads of sediments.
-A review of literature looking at
vegetative filter strips and their
efficiency at removing sediments,
nutrients and pesticides. The two main
factors of VFS width and direction of
flow were discussed.
-A laboratory exp. To investigate
trapping efficiency of VFS was carried
out.
-USA (Virginia, Vermont, Iowa, Georgia), Canada
(Ontario), Sweden (South), Norway (South-east),
Finland (South-west) and Italy (North-east).
-Soil types: groseclose silt loam, sandy loam, loamy
sand, silt loam with sand and clay, typic Cruaquept,
fulvi-calcaric Cambisol.
-Vegetation type: mowed grass, grass, grass-woody,
shrubs and grass, trees and shrubs with grass.
-Study site: Burdekin irrigation area, north Queensland.
Jin CX, Römkens MJM
(2001)
Experimental
studies of factors in
determining sediment
trapping in vegetative
filter
strips.
Transactions of the
ASAE 44, 277-288.
Hydrology/climatic conditions/location
-Soil type: Silt loam (from Neshoba County,
Mississippi).
Results
-One of the primary functions of buffers is to slow surface
water movement which reduces the export of pollutants,
particularly particulate pollutants. Narrow strips of dense grass
can function in this capacity and provide water quality benefits.
-The costs of practice implementation are associated with land
being taken out of production and costs associated with
planting establishing and maintaining buffers.
-In-field practices that distributes flow evenly along buffer is
important to maximize the effectiveness of the systems.
-Rainfall has a major impact on the amount of phosphorus
being removed by buffer zones due to retention times.
-The vegetated wetlands were effective in removing around
40% of atrazine and diuron applied to inlets.
-Suspended solids were also effectively removed by the
wetlands.
-Nutrients were not significantly less in the wetland outlet
compared to the inlet.
- VFS density, flume slope, and sediment particle size were
the main factors in determining the trapping efficiency
- flow rate had a minor effect and sediment concentration had
hardly any effect on the trapping efficiency for the range of
conditions investigated
- Changing the flow rate changes the flow depth and the
resistance due to the vegetative elements, but this hardly
affected the flow velocity, so flow rate has little effect on the
trapping efficiency. However, increasing the flow rate
increases flow depth and the fall distance of the particles in
the flow, so as flow rate increases, sediment deposition moves
downstream. The fall velocity of particles is related to the
particle size and density. Deposited sediment became finer in
20
Reference
Experimental design
Johnson AKL, Ebert
SP, et al. (1997) Spatial
and
temporal
distribution of wetland
and riparian zones in
catchments adjacent to
the Great Barrier Reef
Marine
Park.
In
'GBRMPA
CrossSectional Workshop on
Wetlands and Water
Quality'. Babinda pp. 126
- This paper reviews the role of riparian
and wetland areas in ensuring
ecosystem function and briefly
assesses the status of riparian and
wetland areas in catchments
immediately adjacent to the Great
Barrier Reef Marine Park.
- results of a study
undertaken on the floodplain of the
Herbert River catchment, that assessed
both spatial and
temporal changes in the area of riparian
and wetland zones.
Hydrology/climatic conditions/location
-Study area: Catchments adjacent to the GBRMP
Results
the flow direction. For very fine particles (smaller than 150 µ
m), the VFS width in the flow direction was insufficient to trap
these particles. Most of the fraction smaller than 150 µ m
passed through the VFS.
- All the tests in this study were conducted in non-submerged
shallow overland flow with low flow rates and sediment
concentrations. Flow depths above the VFS were less than
1.44 cm. Inside the filter strip, the flow depth did not exceed
the height of the bristles, and the bristles were erect during all
flows. Once the flow depth exceeds the bristle height and
bends the bristles, the flow hydraulics change. In that case,
the above results are probably not applicable. The results
obtained in this study are thus valid only for shallow, uniform,
non-submerged flow with sediment concentrations less than
the transport capacity of the flow to the VFS
- concerns relating to the decline in riparian and wetland
resources in catchments adjacent to the GBRMP are justified
and requiring of further attention. Given that agricultural
industries in these areas are operating in the context of an
ever-increasing community expectation for the preservation of
riparian and wetland areas, conflict over the use of these
scarce resources is likely to grow in the future.
- · A rapid decline in the area of freshwater wetlands and
riparian forest since European
settlement in the 1860‟s;
· An 80% decrease in the area of freshwater wetlands
(including a 70% decrease since 1943);
· An 80% decrease in the area riparian forest since European
settlement with riparian areas
becoming narrower with time;
· The number of riparian forest and freshwater wetland islands
increased after 1860, however
mean island area decreased;
· Aggregation of freshwater wetland and riparian forest islands
on the floodplain between
1943 and the present;
· Decline in Diversity and Evenness indices as the area of
sugarcane increases; and
· A more uniform/less diverse landscape now exists on the
Herbert coastal floodplain when
compared with historical patterns.
21
Reference
Experimental design
Hydrology/climatic conditions/location
Kao, C.M., J.Y. Wang,
M.J.
Wu.
2001.
Evaluation of atrazine
removal processes in a
wetland. Water Science
and Technology. 44(1112): 539-44
(Kao et al. 2001)
Kao, C.M., J.Y. Wang,
D.F. Chen, H.Y. Lee,
and M.J. Wu. 2002.
Non-point
source
pesticide removal by a
mountainous wetland.
Water Science and
Technology. 46(6-7):
199-206
(Kao et al. 2002)
- can only get abstract, get full paper if
possible.
- Study in McDowell County, north
Carolina, looking at atrazine removal in
a mountainous wetland.
- study conducted march to October
1998
- Receives water from two unnamed creeks draining
primarily agricultural lands
- Hydraulic retention time is approx 10/5days based on
a dye release study.
Klöppel, H., W. Kördel,
and B. Stein. 1997.
Herbicide transport by
surface runoff and
herbicide retention in a
filter strip, rainfall and
runoff
studies.
Chemosphere. 35(1/2):
129-141.
(Klöppel et al. 1997)
- full txt unavailable, retrieve if possible.
- pesticides in a mountainous wetland,
looks at atrazine removal by a
mountainous wetland
- wetland receives water from two
unnamed creeds which drain up
gradient agricultural lands
- monitoring between November 1999 to
march 2001
- also looked at aerobic and anaerobic
bioreactor experiments to evaluate
biodegradation of atrazine in wetland
system
- 2 studies.
- first study:
- rainfall on mesoplot of 1200m2 planted
with triticale
- herbicides dichlorprop-p, isoproturon
and befinox applied to plots.
- plots had soil water content of 30%
(kg/kg).
- initial concentrations of dichlorprop-p
and isoproturon were 1400ug/L.
- grassed filter strip was 10m long, 20m
wide, irrigated one day after herbicide
application
Second study:
- experiments with simulated runoff to
investigate the efficiency of a grassed
filter strip.
Results
- analytical results indicate wetland completely removed
atrazine flushed from up gradient agricultural lands
- field results indicate wetland was able to remove atrazine
flushed from agricultural lands after storm events.
- also found atrazine can be degraded under reductive
dechlorinating conditions when sufficient intrinsic organic
matter was provided
- First study
- rainfall intensity of 14mm/h
- irrigated with simulated rain for 2.5h
Second study
- grassed filter strip irrigated with sprinklers with an
intensity of 14mm/h which corresponds to its infiltration
capacity.
- runoff was simulated by means of a point source at the
top of the grassed filter strip with flow rates of 400l/h.
1500l/h and 2000l/h.
- First study
- runoff in compressed tractor lanes occurred rapidly
- total runoff over whole plot started at a total rainfall of 14mm.
- in total, runoff concentrations ranged from 100ug/L to
200ug/L decreasing with cumulative rainfall
- approximately a linear relationship was obtained between the
logarithm of the dissolved isoproturon and dichlorprop-p conc.
in the runoff samples collected
significant amounts of total surface runoff in the
central outlet leaving the mesoplot occurred only after a
cumulative rainfall of 12-14mm. Surface water discharge was
22
Reference
Experimental design
- simulated runoff containing definite
herbicide concentrations from a point
source was passed over the grassed
strip and was collected at different 10,
15 and 20m distances downslope to the
plot over a width of 10m
- plots with a width of 10m were
prepared in a grassed filter strip situated
between an agricultural field and a
brook.
- point source water was spiked with 50
and 200ug/l of isoproturon, dichlorpropp and terbuthylazine
Hydrology/climatic conditions/location
Results
very low due to a high infiltration capacity of the soil with a
maximum of 350l/h after a total rainfall of 22mm. the
isoproturon and dichlorprop-p concentrations in the runoff
water phase ranged between 100 and 200ug/l (figure 5)
- The main proton of total runoff leaving the treated mesoplot
infiltrated in the grassed filter strip, it was highly diluted by the
irrigation water.
- isoproturon and dichlorprop-p concentrations decreased
quickly with increasing distance to target area.
- at 1m distance, isoproturon concentrations ranged between
13 and 60ug/l and decreasing to 1-8ug/l at 3m distance and to
0.2-0.7ug/l at 5m distance.
- a dependence on the cumulative rainfall was not found.
Second study
- it was shown that the efficiency of the boundary strip in
herbicide retention was mainly due to infiltration of the runoff in
the strip.
- reduction of collected runoff water varied between 0 and 92%
of simulated runoff water caused by local and temporal
variability of infiltration conditions.
- expected that boundary strip length and runoff intensity had
an influence on the effectiveness of the filter strip, however no
significant dependence of the collected runoff amounts was
found for both parameters
- lower intensities of the simulated runoff result in lower
herbicide concentrations in the collected runoff due to a higher
dilution b the simulated rainfall.
- in most cases the herbicide concentrations increased with
increasing water solubility in the order terbuthylaxine<
23
Reference
Experimental design
Hydrology/climatic conditions/location
Results
isoproturon< dischlorprop-p but differences were low.
70-98% terbuthylaxin, 70-98% isoproturon and 6198% dichlorprop-p were removed by the grassed
filter strips.in the 10m long filter strops on an average 80 +11% terbuthylazine, 79 +- 12% isoproturon and 74+15% dichlorprop-p were removed.
- at 15m and 20m downslope the filter strips for all
three herbicides retention on average increased to more than
-
Krutz,
L.J.,
S.A.
Senseman,
M.C.
Dozier, D.W. Hoffman,
D.P. Tierney. 2003a.
Infiltration
and
adsorption of dissolved
atrazine and atrazine
metabolites
in
- looking at contribution of mass of
adsorbed pesticide to VFS trapping
efficiency.
- This study looking at atrazine and its
metabolites, diaminoatrazine (DA),
deisopropylatrazine (DIA),
desethylatrazine (DEA) and
hydroxyatrazine (HA) in buffalo grass
- runoff applied at 750L/hr
90%
- during 60 minute simulation, trapping efficiency was
significantly greater for atrazine 22.2% compared to atrazine
metabolites (19.0%).
- approximately 67% and 33% of trapping efficiency was
attributed to infiltration and adsorption respectively.
24
Reference
buffalograss filter strips.
Journal
of
Environmental Quality.
32: 2319-2324
(Krutz et al. 2003a)
Experimental design
(Buchloe dactyloides) VFS.
- study conducted in June 2001 and
2002 at Blackland Research Centre in
Temple, TX
- runoff applied as a point source
upslope of a 1x3m microwatershed plot,
at a rate of 750L/hr.
- point source fortified at 0.1ug/ml
atrazine, DA, DIA, DEA, and HA
- after crossing length of the plot, water
was collected at 5min intervals
Hydrology/climatic conditions/location
Results
Krutz,
L.J.,
S.A.
Senseman,
K.J.
McInnes, D.A. Zuberer
and D.P. Tierney.
2003b. Adsorption and
desorption of Atrazine,
Desethylatrazine,
Deisopropylatrazine
and Hydroxyatrazine in
vegetated filter strip and
cultivated soil. Journal
of Agricultural and Food
Chemistry. 51: 73797384.
(Krutz et al. 2003b)
Krutz,
L.J.,
S.A.
Senseman,
M.C.
Dozier, D.W. Hoffman,
D.P. Tierney. 2004.
Infiltration
and
adsorption of dissolved
metolachlor,
metolachlor
oxanilic
acid, and metolachlor
ethanesulfonic acid by
buffalograss
(uchloe
dactyloides) filter strips.
Weed Science. 52:166171
- maybe not that useful…
- looked at adsorption and desorption
of atrazine, desethylatrazine (DEA),
Deisopropylatrazine (DIA) and
hydroxyatrazine (HA) compared
between a 12yr old vegetated filter
strips (VFS) with a mix of bermucagrass
(Cynodon dactylon) and buffalograss
(Buchle dactyloides) and a cultivated
Houston Black clay (CS).
- evaluated physical and chemical
properties were similar, except a 1.7fold
increase in organic carbon content of
the VFS
- adsorption and desorption coefficients for atrazine were at
least 59% higher in the VFS than the CS.
- adsorption coefficient was 48% higher for HA in VFS
compared with CS, but desorption not statistically different
between soils
- adsorption ad desorption coefficients for DEA and DIA not
statistically different between soils
- study investigates contribution of
adsorption and infiltration to trapping
efficiency of metolachlor, metilachlor
oxanilic acid (OA) and metolachlor
ethanesulfonic acid (EFA) in buffalo
grass filter strips
- runoff applied as a point source
upslope of a 1x3m microwatershed plot,
at a rate of 750L/hr.
- point source was fortified with
metolachlor, metolachlor OA and
metolachlor ESA each at 0.12ug/ml
- after crossing length of the plot, water
was collected at 5min intervals
- trapping efficiency significantly greater for metolachlor
(25.3%) as compared with the OA (15.5%) and ESA
metabolites (14.2%).
- Average infiltration was 8.5% and was not significantly
different among compounds.
- significantly more metolachlor (17.3%) was retained as
adsorbed compared with metolachlor OA (7%) or metolachlor
ESA (5.5%)
- adsorption accounted for 68 and 42% of the total trapping
efficiency for metlachlor and metolachlor metabolites
respectively
25
Reference
(Krutz et al. 2004)
Experimental design
- study conducted in June 2001 and
2002 at Blackland Research Centre in
Temple, TX
Hydrology/climatic conditions/location
Results
Krutz LJ, Senseman
SA, et al. (2005)
Reducing
herbicide
runoff from agricultural
fields with vegetative
filter strips: a review.
Weed science 53, 353367.
-A review of the methods developed for
evaluating herbicide retention in VFS;
ascertain the efficacy of VFS regarding
abating herbicide runoff; identify
parameters that affect herbicide
retention in VFS; review the
environmental fate of herbicides
retained by VFS; and identify future
research needs.
-simulated rainfall intensities in the literature range from
1.9 to 25.4 cm hr-1
Lin, C., R. Lerch, et al.
(2004). "Incorporating
forage grasses in
riparian buffers for
bioremediation
of
atrazine,
isoxaflutole
and nitrate in Missouri."
Agroforestry systems
63(1): 91-99.
-Greenhouse and field trials to evaluate
tolerance of plant species to herbicides
(atrazine and Balance™) and their
capacity to sequester and degrade
these herbicides.
-Plant species include: Orchard grass
(Dactylis glomerata), smooth
bromegrass (Bromus inermis), tall
fescue (Festuca arundinacea), timothy
(Phleum pretense), and switchgrass
(Panicum virgatum).
-Uses a mass balance approach.
Study objective to identify desirable
plant species for bioremediation treeshrub-grass buffer systems.
-literature with data pertaining to
vegetated buffers and sediment
trapping efficiency was collated (a total
of over 80 papers).
-Study in the Midwestern region of the U.S.
-Sandy loam soil type.
- No study has documented a decline in the concentration of
herbicides in receiving water bodies in response to the
installation of filter strips at the watershed scale. It is
imperative that future research addresses this research gap.
- The retention of herbicides as a function of VFS width
depends largely on the properties of the herbicide evaluated.
-The type of vegetation established in VFS is expected to
affect herbicide retention because of differences in their ability
to promote sedimentation, infiltration, and sorption to leaves,
stems, and thatch.
-Switchgrass, tall fescue and smooth bromegrass are effective
at bioremediation of atrazine and Balance™ it is believed this
is contributed by their forage plant characteristics including a
high microbial population in the rhizosphere.
Liu, X., X. Zhang, et al.
(2008). "Major factors
influencing the efficacy
of vegetated buffers on
-Data sourced from: U.S, Netherlands, France, Canada,
Germany, and Central Europe.
-The efficacy of a vegetated buffer is influenced by buffer
width, slope, area ratio, rainfall and vegetation.
-The stepwise regression analysis identified buffer slope and
width as the two most important factors when determining
26
Reference
sediment trapping: A
review and analysis."
Journal
of
Environmental Quality
37(5): 1667-1674.
Experimental design
-Using literature data, a model
(stepwise regression analysis) was
performed to analyze the relationship
between sediment trapping efficacy and
buffer width and slope (respectively).
Hydrology/climatic conditions/location
Lizotte,
R.E.,
F.
Douglas Shields, S.S.
Knight and C.T. Bryant.
2009. Efficiency of a
modified
backwater
wetland in trapping a
pesticide
mixture.
Ecohydrology. 2: 287293
(Lizotte et al. 2009)
- looking at pesticide trapping efficiency
of a modified backwater wetland
amended with a mixture of atrazine Smetolachlor and fipronil
-700m long 25m wide wetland located
along the Coldwater River in Tunica
County, Mississippi, USA
- pesticide mixture amended into the
wetland at the upstream weir simulating
a 1hr, 1-27cm rainfall event from 16ha
agricultural field
- study conducted on June 20th 2007
- simulated runoff
- a 1-h, 1-27cm rainfall event
- during simulated rainfall event approx 730m3 of water
was released from the upstream lake cell portion of the
backwater into the modified wetland cell portion over
about 4h
- water temperature ranged from 24 to 28 degrees C
- rainfall events of 41mm on days 11-12 and 74mm on
day 20
Results
sediment removal efficacy.
-Buffers should therefore be built with a specific slope to
optimize sediment trapping efficacy.
- peak pesticide concentration observed upstream 1hr after
injection
- rapid pesticide removal from upstream water occurred with
63, 51 and 61% decrease of atrazine, S-metolachlor and
fipronil respectively by 24h.
- by day 7, 79 80, and 87% decreases from peak
concentrations occurred.
- after day 28 all pesticide concentrations were ,0.3ug/l and
after day 56, no target pesticides were detected.
- downstream atrazine occurred in trace amounts (<0.4ug/l)
within 24h and after day 28 was not detectable.
S- metolachlor occurred once downstream on day 21
(0.249ug/L) and fipronil was detected on days 15-56 in trace
amounts (<0.05ug/l).
- results indicate that modified backwater wetlands can
efficiently trap pesticides in runoff from agricultural fields
during small to moderate rainfall events
- pesticide concentrations were not detectable in water
samples collected prior to pesticide amendment at either the
upstream or downstream sites
rainfall occurred on days 11,12 and 20 and prior o sampling
days 15 and 21, rainfall did not appear to significantly affect
27
Reference
Experimental design
Hydrology/climatic conditions/location
Loch RJ, Espigares T,
et al. (1999) Vegetative
filter strips to control
sediment movement in
forest
plantations:
validation of a simple
model using field data.
Australian Journal of
Soil Research 37, 929946.
-Looks at sediment movement through
vegetative barriers used in forest
plantation management in south-east
Queensland.
-Development of simple methodology
for predicting sediment movement
through these barriers.
-Study sites: Toolara and Imbil (Queensland).
-Soil type: coarse-textured soils of Queensland‟s
coastal lowlands (used for Pinus plantations) and finer
textured soils (used for Araucaria plantations) in sub
tropical south-east Queensland.
Lowrance,
R.,
G.
Vellidis,
R.D.
Wauchope, P. Gay,
D.D. Bosch. 1997.
Herbicide transport in a
managed riparian forest
buffer
system.
American Society of
Agricultural Engineers.
40(4): 1047-1057
(Lowrance et al. 1997)
- studied the effect of a riparian forest
buffer system (RFBS) on transport of
atrazine and alachlor in 1992-1994.
- herbicides applied to an upland corn
crop in March of each year
- buffer system averaged 50m in width
- system included a grass buffer strip
immediately adjacent to the field (Zone
3), a managed pine forest downslope
from the grass buffer (zone 2), and a
narrow hardwood forest containing the
stream channel system (zone 1)
- after the first year of the study, the
- about 25cm of cumulative rainfall after herbicide
application before June 30th
- climate in the area is humid subtropical providing
abundant rainfall and a long growing season.
- average monthly temps range from 11 degrees C in
Jan to 27 degrees C in July and august, with a 47yr
mean annual temp of 19.2 degrees C
- precipitation generally low from sep to nov and rain
increases in dec to early may
- summer thunderstorms and tropical depressions
cause July and august to be wetter months on average
Results
pesticide concentrations within the wetland.
- peak pesticide concentrations (12.997, 6.658 and 0.817 ug/l
of atrazine, S-metolachlor and fipronil respectively were
observed 1.25hr after initial amendment at the upstream
injection site during the simulated rainfall event and were used
as a baseline to determine trapping efficiency within the
wetland during the 56 day study period
- two days after pesticide amendment, aqueous
concentrations decreased by 6, 51 and 62% for atrazine, smetolachlor and fipronil respectively
- atrazine and fipronil were detected up to 28 days post
injection upstream whereas s-metolachlor was detected only
up to 21 days. None detected at the upstream site after
56days
-For plots that did not erode, the degree of sediment trapping,
if based on total sediment only, was quite variable. However, if
rates of transport were considered in terms of the various size
fractions, results were very consistent.
-A simple conceptual approach equating the vegetated area to
a sedimentation pond allowed deposition to be calculated on
the basis of settling velocity, flow depth, and residence time
within the vegetated area.
-Estimated transport rates of sediment through the vegetated
areas were in close agreement with measured transport rates,
confirming the efficiency of this approach.
-The results highlight a number of issues for management of
sediment movement from forest estates.
- most of the herbicide transport in surface runoff occurred
before 30th June with about 25cm of cumulative rainfall after
herbicide application
- during this period of higher herbicide transport, atrazine and
alachlor conc., averaging 34.1ug/l and 9.1ug/l at the field edge
respectively, were reduced to 1ug/l or less as runoff neared
the stream.
- there were generally no differences among the mature forest
and the two treatment areas (clear cut and thinned) for either
concentration or load in surface runoff.
- concentration reduction was greatest per meter of flow length
in the grass buffer adjacent to the field
- only minor transport of herbicides through the buffer system
28
Reference
Experimental design
managed forest was clear cut in 1/3 and
thinned in 1/3 of zone 2. The other 1/3
of zone 2 was left s mature forest
- study conducted at a research farm
(Gibbs Farm) par of the University of
Georgia Coastal Plain Experiment
Station near Tifton, Georgia
Hydrology/climatic conditions/location
Results
in shallow groundwater and little difference between the zone
2 treatment areas
Lymburner L, Hairsine
PB, et al. Indices for
Assessing the Spatial
Distribution
and
Functions of Riparian
Buffer Zones.
- This paper describes three indices,
which quantify the spatial distribution of
riparian zones that function as buffers.
- Indices have been developed based
on a review of point-based riparian zone
studies of sediment and pollutant
trapping, and are designed with spatial
extrapolation in mind.
- The indices describe the following
pollutant trapping functions: 1. hillslope
runoff interception, 2. hillslope sediment
trapping, and 3. hillslope pollutant
Trapping
- This suite of indices provides a
measure of stream condition that
explicitly considers buffering functions
and permits a more process specific
design procedure in planning catchment
management.
McJannet, D. (2007).
Towards
an
understanding of the
filter function of tropical
wetlands, CSIRO.
-Development of a field measurement
program to determine filter function of
wetlands in North Queensland.
-Water balance instrumental design.
-Kyambul wetland (Tropical North Queensland).
-The use of a model and synthetic dataset resulted in a
sampling strategy that had more sampling effort in the wet
season compared to the dry season to account for seasonality
and extreme nature of rainfall in this area.
-No results on actual sampling were presented..
McKergow, L. A., I. P.
Prosser, et al. (2006b).
"Performance of grass
-A study that compared 10m wide
regenerating grass and eucalyptus
globules buffer performance with regard
-Albany, Western Australia.
-Mediterranean type weather conditions.
-Highest rainfall between April-October.
-The grass buffer was effective at trapping nutrients and
sediment from surface runoff. Trapping efficacy for eucalyptus
globules was lower.
-Indices have been presented that describe the spatial
distribution of three functions of the riparian zone. These
indices are based on point based research, and have been
adapted to enable calculation using spatial data sets. The
accuracy of these indices is limited to the accuracy of the
spatial data from which they are calculated, however they
provide a level of information about the spatial distribution and
effectiveness of riparian filter strips throughout the catchment
that has been unavailable up to now.
29
Reference
and eucalyptus riparian
buffers in a pasture
catchment,
Western
Australia, part 2: water
quality." Hydrological
processes
20(11):
2327-2346.
Matos A, Pinho A, et al.
(2008)
Streamside
management
zone
(SMZ) efficiency in
herbicide retention from
simulated surface flow.
Planta Daninha 26,
131-142.
Experimental design
to sediment and nutrient trapping.
-Compared different flow vectors
(surface runoff, subsurface flow and
stream flow).
Hydrology/climatic conditions/location
-Low rolling hill topography.
Results
-Differences in trapping can be attributed to infiltration ability
during summer storms. The grass cover provided for soil
infiltration while the other had a crust layer on soil which
repelled water.
-In areas where subsurface flow is dominant other methods
other than riparian buffers may be required for sediment and
nutrient trapping.
-Results showed that, on average, a 10 m long forested SMZ
removed around 25% of the initial concentration of atrazine
and was generally ineffective in reducing the more soluble
picloram.
-Retention of picloram was only 6% of the applied quantity.
-Percentages of mass reduction by infiltration were 36% for
atrazine and 20% for picloram. Stronger relationships existed
between O horizon depth and atrazine retention than in any
other measured variable, suggesting that better solid-solution
contact associated with flow through deeper O horizons is
more important than either velocity or soil moisture as a
determinant of sorption.
- Plot-scale overland flow experiments
were conducted to evaluate the
efficiency of streamside management
zones (SMZs) in retaining herbicides in
runoff generated from silvicultural
activities.
- Herbicide retention was evaluated for
five different slopes (2, 5, 10, 15, and
20%), two
cover conditions (undisturbed O horizon
and raked surface), and two periods
under contrasting soil moisture
conditions (summer dry and winter wet
season) and correlated to O horizon
and site conditions.
-herbicides used: Picloram (highly
soluble in water) and atrazine
(moderately sorbed into soil particles)
-Study sites: northeastern Georgia, U.S.
Melbourne
Water
(2002)
'Constructed
Wetland
Systems:
Design Guidelines for
Developers.'
(Melbourne Water)
-A report looking at best management
practices of constructed wetlands and
information for the development of
these systems.
-The report was produced by a Melbourne water
supplier with the intention of improving storm-water runoff treatment.
-Intended for urban use.
-The intention of removing suspended sediments, nutrients
and other toxicants.
Mersie,
W.,
C.A.
Seybold, C. McNamee,
M.A. Lawson. 2003.
Abating
endosulfan
from
runoff
using
vegetative filter strips:
the importance of plant
species and flow rate.
- compare and determine effectiveness
of switchgrass (Panicum virgatum) and
tall fescue (Festuca arundinacea) for
removal of endosulfan under different
flow rates
- runoff simulated by applying runon containing
endosulfan at the up slope section of the beds at 2.71
or 6.01min-1 over 0.9m wide soil surface
- the two application flow rates were chosen to
represent different rainfall intensity and hence runoff
events.
- slow rate (2.71min-1) will simulate runoff from
conditions of low rainfall intensity and a relatively small
- no preferential removal of one endosulfan isomer over the
other ( or )
- total endosulfan removed ranged from 98 to 100% (of
applied) for the 2.71min-1 runon application rate, and 39-54%
for the .01min-1 runon application rate
- all the applied runon infiltrated the tall fescue planted beds at
the slower flow rate whereas at the faster rate only 29%
penetrated the fescue bed
30
Reference
Agriculture, Ecosystems
and Environment. 97:
215-223
(Mersie et al. 2003)
Experimental design
Hydrology/climatic conditions/location
vegetable production. Faster flow rate will represent
conditions that are typical of areas where there is
frequent and heavy rainfall
Results
- from overland flow, concentrations of endosulfan were
reduced by about 60-80% at the 2.71min-1 application rate
and by 27-39% at the 6.01mn-1 runon application rate.
- adsorption to soil is the primary mechanism for removal of
endosulfan from overland flow and leachate
- the effectiveness of the grasses were more important when
the runon moves fast
- at both flow rates, more endosulfan absorbed to the soil in
the first 0-67cm section of the beds and adsorbed to the soil in
the top 0-10cm depth. I.e. most was removed in the first one
third of the filter strip
-the percentage of total runon that infiltrated (leachate +
unrecovered) the filter strips was significantly greater at the
2.71min-1 application rate than at the 6.01min runon
application rate, this indicates that the rate of runon entering
the filter strip affects the amount of infiltration
- concentration of endosulfan in surface runoff samples ranged
from 80 to 200ug/l for the 2.71min-1 runon application rate and
from 250 to 400ug/l for the 0.01min-a rate
- the quantities of endosulfan that were filtered out of the
runon as it passed across the filter strip were significantly
greater at the 2.71min-1 than at the 6.01min-1 runon
application rate
- endosulfan conc. in surface runoff reduced by 60-80% in
2.71min-1 flow and 27-39% in 6.01min flow
31
Reference
Experimental design
Mickelson, S.K., J.L.
Baker and S.I. Ahmed.
2003. Vegetative filter
strips for reducing
atrazine and sediment
runoff
transport1.
Journal of Soil and
Water
Conservation.
58(6) 359
(Mickelson et al. 2003)
- Rainfall simulation performed on
twelve VFS, six 1.5x4.6m and six
1.5x9.1m to determine 1. The effects of
VFS on atrazine and sediment transport
in runoff inflow with an average of
7650mg/l sediment (WS) and no
sediment (NS) and 2. The effects of
VFS length and area ratio on atrazine
and sediment transport
- herbicide runoff losses simulated by
adding a dilute atrazine solution as
inflow to upper end of VFS
- field study conducted at the Agronomy
and Agricultural Engineering Research
Centre of Iowa State University in
Ames, Iowa
- rainfall simulation study
- conducted under summer conditions (Iowa)
-A study looking at currently employed
VFS to assess the most appropriate
characteristics for sediment and nutrient
trapping ability.
-Study sites were within the Rock Creek Watershed
(Newton), Iowa.
Mickelson, S. K., M.
Helmers, et al. (2004).
Vegetative Filter
Education and
Assessment in the
State of Iowa.
2004IA63B.
Hydrology/climatic conditions/location
- the desired rainfall volume was 66mm although there
was some variation (coefficient of variation = 9.6%)
around this value in the amount collected
- inflow into all vegetated filter strips was intended to me
30L/min. Although that was the initial rate, the inflow
rate for each plot later decreased with time.
- the time of travel of water for the 4.6m VFS was about
120 seconds, it was about twice that for the 9.1m VFS,
therefore the velocity for both was about 2.3m/min
Results
- there was no significant difference in atrazine transport
between the with sediment and the without sediment
treatments
- the 80%reduction in atrazine transport for the 9.1m VFS was
significantly greater than the 31% reduction for the 4.6m VFS
- infiltration of inflow was a dominant factor in reducing
atrazine transport with VFS
- on average atrazine retention with 4.6m VFS was 27.2% for
with sediment and 36.3% for without sediment
- for 9.1m strips, atrazine retention was 74.6% and 83.5% for
with and without sediment treatments respectively
- VFS length found to be a significant factor for atrazine
removal from inflow, with doubling the length at least doubling
the retention
-The first 5m of the VFS plays a significant role in removal of
suspended solids (>40µm). Length >10m does not
significantly improve VFS performance.
-Infiltration is the only mechanism that allows for removal of
smaller size sediments (<40µm). Vegetative cover helps to
reduce velocity of runoff and increase residence time for water
to infiltrate.
-High vegetation density leads to less erosion and less
transport capacity of the runoff and therefore greater settling of
32
Reference
Experimental design
Mitsch WIJ (1992)
Landscape design and
the role of created,
restored, and natural
riparian wetlands in
controlling nonpoint
source pollution.
Ecological Engineering
1, 27-47.
-Design principles, landscape locations
and case studies of natural and
constructed riverine wetlands for the
control of nonpoint source water
pollution are discussed.
-Comparison of natural and artificial
wetland systems and their ability to
retain sediments and nutrients.
-Study sites within the northern Ohio watershed and
southern Illinois.
-There appears to be greater efficiency was present in the
artificial wetland for the retention of phosphorus.
-It is suggested that the human input into wetland construction
design be simple without too much physical engineering or
addition of too many introduced species. It is most important
that the systems are self-regulating and self-maintaining.
Moore, M., D. Denton,
et al. (2008). "Mitigation
assessment of
vegetated drainage
ditches for collecting
irrigation runoff in
California."
-Comparison between u-shaped and vshaped vegetative drains and a vshaped non-vegetative drain for
removal of pesticides (diazinon and
chlorpyrifos).
-Simulated irrigation runoff
concentrations were 0.02 mg/L
permethrin and 0.19 mg/L diazinon.
-Irrigation was applied at max flow rate
of 1702 L/h
-investigated
the forms of P in runoff from a dairy
pasture of high fertility
-3·6-ha paddock
-paddock drains to a natural depression
and a culvert where water was
redirected to be monitored.
-prior to monitoring, aprox 60 kg/ha of P
was applied using a trailing spinner;
80% single superphosphate and 20%
-Yolo County, California.
-Soil type: Yolo silt loam and Reiff very fine sandy loam.
-Slope of 0.2% (north to south) and 15% (west to east).
- Irrigation was applied at max flow rate of 1702 L/h for
8 hours.
-Pyrethroids, because of their short half lives are effectively
mitigated by the use of vegetated ditches.
-The vegetated ditch (v-shape) reduced pesticide
concentrations by 2.3 to 2.8 times more than the un-vegetated
ditch (v-shape).
-U-shaped vegetative ditches performed better than v-shaped
vegetative ditches.
-Darnum in West Gippsland, Victoria
-average rainfall for the area is approx 1000 mm/year
between May and November
-minimum evaporation between May and September
-paddock is part of a 120-ha farm on which 330 dairy
cows graze
-pasture of predominantly perennial ryegrass (Lolium
perenne) cv.
Ellett and white clover (Trifolium repens)
-Darnum catchment, the major runoff events occurred when
the soil was saturated
-low settling velocities of materials <0·45 μm and the amount
of P moving in larger storms would suggest that buffer strips
and riparian zones are unlikely to decrease P losses
substantially from dairy pastures in this area
-no apparent relationship (P > 0·05) between P concentration
and soil cover, which supports the contention that
erosion was not the major mechanism for P transport
-control measures which simply limit erosion will be similarly
Nash, D., and Murdoch,
C. (1997). Phosphorus
in runoff from a fertile
dairy pasture.
Australian Journal of
Soil Science 35, 419429
(Nash et al. 1997)
Hydrology/climatic conditions/location
Results
sediments.
-Non-submerged vegetation allows for the greatest flow
retardation and minimum sediment transport capacity.
-Perpendicular planting may be an effective means of
managing non-uniform or concentrated flow by slowing down
flow velocity.
-Time elapsed between the time of pesticide application and
rainfall event has an important role in pesticide losses.
- Pesticide losses in VFS are reflected by adsorption
properties of the pesticides.
33
Reference
Norris, V. (1993). The
use of buffer zones to
protect water quality: A
Review.
Water
Resources
Management 7, 257272
(Norris et al. 1993)
Experimental design
diammonium phosphate.
-Autumn 1994: installed diversion wall,
150mm RBC flume/457mm rectangular
weir combination, ISCO storm
monitoring system (Model 3700
automatic sampler, Model 3230 bubbler
flowmeter, Model 674 rain gauge).
-groundwater sampled by peizometer at
varying depths
-water sampled analyzed for DRP, TRP,
TDP and TP.
-soil cover measured
-data examined graphically, analysed by
linear regression using S-Plus 3.2
-A review on application and
effectiveness of vegetated buffer zones
-provides guidelines on their use for
water quality control
-literature overview
RUNOFF PLOTS:
-Doyle et al. (1975) measured faecal
coliform, faecal streptococci, TSP,
potassium, sodium, nitrate, NH4,
organic nitrgogen at various distances
from the plot.
-Moore et al.(1983) used computer
simulation
-Rohde et al. (1980) had 3 plots,
slopes<3%
-2 yr study
-Fitzpatrick (1984) soil plots 20m2.
Runoff flowed through crop, then
through pasture buffer strips, then was
Hydrology/climatic conditions/location
-Boolarra Loam (Poutsma and Turvey 1979), a yellow
podzolic soil
-Rainfall records from
Ellinbank indicate that rainfall was well below average
for much of 1994
-Subsurface water from the peiziometers had an
average total P concentration of 0·03 mg/L
-soils of low permeability need wider buffer strips that
highly permeable soils
-convex slope creates faster overland flow and required
wider buffer strips to slow the flow
-3 categories reviewed:
Runoff plots/confined field areas, Operational forestry
catchments, and Agricultural catchments
RUNOFF PLOTS:
-Doyle et al. (1975) investigated forest buffer zones and
manure polluted runoff. Concluded that a 7.6m buffer
was sufficient to prevent stream pollution
- studied a 0.19ha plot, 4% slope, alfalfa groundcover,
manured at 90t/ha.
-Moore et al (1983) studied dairy waste runoff.
-Rohde et al. (1980) investigated movement of trifluralin
Results
ineffective at preventing P losses under the conditions that
prevailed in this study
-Runoff from a single storm system over 8 days in early
November accounted for 56% of the total runoff volume and
69% of the P lost (Table 3)
-DRP attach readily to particulate materials during transport
(runoff)
-In years of above average rainfall, P loads in runoff water
may increase.
-P is lost from some systems in a dissolved form due to
dissolution processes near soil surface
-Effectiveness of buffer strips is partly based on physical
properties: structure/species of vegetation,
length/gradient/shape of runoff area(width and slope),
length/gradient/slope upstream, rate of surface water flow,
depth of surface water vs vegetation height and density,
hydraulic conductivity and holding capacity of buffer zone soil.
-pollutants transported in particulate form require that the
buffer zone reduces energy of overland flow, to allow
deposition
- pollutants in dissolved form require the buffer to detain runoff
long enough for the decay of pollutants, or uptake by plants
-groundcover most crucial aspect of a buffer zone
(grass/herb/shrub)
-Studies show that small controlled runoff plots with buffers 510m in width are successful in removing a variety of pollutants
from overland flow (sediment, nutrients, chemicals)
-Studies show that confined agricultural fields/adjacent riparian
vegetation also remove nutrients and sediment from runoff
-Streamside strips in forestry operations reduce nutrient and
sediment levels in runoff more effectively than in agricultural
catchments.
-Effectiveness of buffer strips on a catchment wide basis
varies, and required coordinated arrangements
34
Reference
Experimental design
sampled and analysed.
-Jacobs and Guillam (1985) undertook a
3 year study, where subsurface
drainage was sampled from transects of
shallow groundwater wells, located
downstream from 7 fields
Hydrology/climatic conditions/location
in runoff.
a)3400sqm watershed withough a buffer strip after
natural rainfall
b) 3 plots, 28m2, without a buffer strip, after simulated
rainfall
c) 2 plots, 28m2, where runoff after simulated rainfall
was directed into grassed waterways 20m in length.
-Fitzpatrick (1984) growing potatoes.
Results
-operation and effectivess of vegetated buffer zones appear to
be unclear and unpredictable
-suggested that use of buffer strips is an impracticable method
for water quality control on a BROAD CATCHMENT SCALE
- Many agricultural catchments in areas of low slope therefore
contain cleared uplands with unbuffered drainage lines. Runoff
from these areas becomes channelised in the upper
catchment and may flow out of the catchment unaffected by
buffer zones further downstream.
-Failure of buffer zones to improve water quality is generally
attributed to inadequate structure, I.E., too narrow,
impermeable to runoff, inadequate vegetation
-Jacobs and Gilliam(1985) studied fate of nitrogen
leaving cultivated fields in 2 watersheds in the North
Carolina Coastal Plain
Nguyen L, Downes M,
et al. (1999) Riparian
wetland processing of
nitrogen, phosphorus
-An investigation into the ability of a
riparian wetland to strip nutrients and
suspended sediment from surface
runoff and groundwater over a 6-month
-Karr and Schlosser (1978) cited a 15year study of
nitrate and sediment movement in forest runoff
-Martin and Pierce (1980) measured nitrate and calcium
ion concentrations in streams draining forested
watersheds in New Hampshire
-Hansmann and Phinney (1973) studied in-stream
algae, dissolved oxygen and suspended sediment loads
after logging practices
-Borg et al. (1988) studied buffer zones in forestry
operations over 2 years using logging trials in southern
forests of WA
-Omernick et al. (1981) undertook a nation-wide study
in the USA, questioning the ability of buffer strips along
streams in agricultural areas to reduce long term stream
nutrient levels.
-Study site: Hill country, Whatawhata (Waikato), New
Zealand.
-Soil type: Well-drained brown granular loam of the
Naike Clay series.
-Over 6 months the wetland was a significant sink for nutrients
(P and N, (predominantly NO3-).
The wetland was a source of some nutrients also (NH4+ and
particulate N).
35
Reference
and
suspended
sediment inputs from
hill country sheepgrazed catchment in
New
Zealand.
In
'Second
Australian
Stream Management
Conference'. Adelaide
pp. 481-485
Experimental design
period when most of the annual water
flows from a sheep-grazed pasture
catchment to the wetland occurred.
Oliver, D. P. and R. S.
Kookana
(2006).
"Minimising
off-site
movement
of
contaminants in furrow
irrigation
using
polyacrylamide (PAM).
I.
Pesticides."
Australian journal of soil
research 44(6): 551560.
Otto, S., Vianello, M.,
Infantino, A., Zanin, G.,
and Di Guaro, A.D.
(2008). Effect of full
grown vegetative filter
strip on herbicide runoff:
Maintaining of filter
capacity over time.
Chemosphere 71, 7882
-The study looks at the addition of
polyacrylamide (PAM) into irrigation
water to reduce off-site movement of
pesticides.
-Pesticides include: endosulfan,
bupirimate, chlorothalonil and atrazine.
-Kununurra region, Western Australia.
-Furrow-irrigated agricultural land.
-The addition of PAM significantly reduced the suspended
sediment load, (total) endosulfan and chlorothalonil leaving the
irrigation bays.
-PAM did not significantly reduce the concentration of weakly
sorbed pesticides bupirimate and atrazine.
-Further work is required to assess the impact of the method.
- runoff of the herbicides metolachlor
and terbuthylazine were monitored in
2002 and 2003
- aims of paper are to: assess
performance of difference VFS in
reducing herbicide concentrations and
losses 5 and 6 years after
establishment; compare effectiveness
over time in relation to growth; identify
VFS and field properties that
characterize the ability to reduce
pesticide runoff.
-VFS made up of herbaceous cover
(Festuca arundinacea) and rows of
alternating shrubs and trees (Viburnum
opulus & Platanus hybrid). Coppicing
was undertaken ever 6years since 1997
when first established
-experimental site was 200m x 35m;
1.8% slope towards a ditch; plot sizes
-experimental site located at the Padova University
Experimental Farm, Po Valley, in North-east Italy
-5year old and 6year old vegetated buffer zones
-Soil type = Fulvic-Calcaric Cambisol, rich in limestone,
silty-loam texture
-Soil pH 8.11
-low organic carbon content (0.92%)
-med-low hydraulic conductivity
-annual rainfall approx 805mm, mainly falls between
spring and autumn
-Narrow vegetative filter strips (VFS) proved to effectively
reduce herbicide runoff from cultivated fields due to the ability
of vegetation to hold surface runoff, promote infiltration and
adsorb herbicides.
-VFS are dynamic systems, so their performance would not
remain constant over the years indicating the need for suitable
buffer management.
- Six metres wide VFS are very effective in reducing runoff
volume and concentration during both wet and dry years.
-Classification analysis showed that runoff concentration and
volume are linked to the characteristics of the rainfall event,
buffer, source of herbicides and time after application.
-Regression analysis showed the significant predictors for
runoff volume are rainfall amount and intensity, total vegetal
cover in the VFS, crop leaf area index and time after
treatment; for concentration they are rainfall intensity, crop leaf
area index and total vegetal cover in the VFS.
-Herbicide physical-chemical properties: metolachlor and
terbuthylazine were found in similar concentrations through
the sampling season.
(Otto et al. 2008)
Hydrology/climatic conditions/location
Results
-Suspended sediment retained in the wetland under low flow
conditions was probably washed out at these high flow rates.
36
Reference
Page, D., Dillon, P.,
Mueller,
J.,
and
Bartkow, M. (2010).
Quantification
of
herbicide removal in a
constructed
wetland
using passive samplers
and composite water
Experimental design
20m x 35m.
-4 types of VFS between the cropland
and the ditch, compared to a plot
without VFS
a) 3m wide buffer, grass only
b) 3m wide buffer, grass + a shrub and
tree row
c) 6m wide buffer with 1 row of trees
and shrubs
d) 6m wide buffer with 2 rows of trees
and shrubs
-cropland upslope was sown with Maize
and pre-emergent herbicides four days
following (metolachlor & terbuthylazine
at 1.37 and 1kg/ha)
-water sampling undertaken at time of
herbicide application until residual
herbicide in surface soil had almost
disappeared.
-water volume measured after runoff
event, sampled taken to analyze for
herbicides
-Statistical analyses undertaken
included;
a) Levene test of homogeneity of
variances for one-way analysis of
variance
b) Newman-Keuls test for pairwise
comparison
c) Pearsons‟s r for simple correlations
d) general regression model tested
-statistics performed with Statistica 7.0
(StatSoft Inc., 2005)
-study aimed to estimate the removal of
selected herbicides in stormwater by a
constructed
wetland using composite water quality
monitoring and passive samplers
- Due to the lower detection limits of
diuron, simazine and atrazine, the use
of passive samplers provides a more
Hydrology/climatic conditions/location
- four week study duration
-Parafield stormwater harvesting system, located on the
Parafield airport, Adelaide Australia.
-Parafield systems incorporates a series of detention
basins and a constructed wetland. It is designed to
capture urban stormwater and treat it to a suitable
standard for water recycling via an aquifer storage and
recovery system (ASR)
Results
-Metolachlor was more widely distributed and more mobile,
but is less persistent, I.E. After 14d residual amounts of both
herbicides is equal; after 45d terbuthylazine is double that of
metolachlor.
- the wetland was effective in reducing the concentrations of
diuron, simazine and atrazine
- Concentrations of these herbicides generally halved as a
result of passage through the constructed wetland with a
design hydraulic retention time of 7 d. Simple ratios of the inlet
and outlet herbicide concentrations
as well as hydraulic load-based methods of measuring the
wetland‟s removal efficiency resulted in a range of estimations
37
Reference
quality
monitoring.
Chemosphere
(Page et al. 2010)
Parsons, J.E., Daniels,
R.B., Gilliam, J.W., and
Dillaha, T.A. (1994).
Reduction in sediment
and chemical load in
agricultural field runoff
by vegetative filter
strips. Department of
Biological and
Agricultural
Engineering1
Department of Soil
Science2
College of Agriculture
and Life Sciences
North Carolina State
University
Raleigh, NC 276957625
(Parsons et al. 1994)
Experimental design
efficient technique than conventional
sampling for assessment of stormwater
wetland treatment.
-Water flows measured at the outlet,
water levels monitored
-2 methods of water sampling;
composite and passive at the inlet and
outlet over a 28d period in 2007 (septOct)
Hydrology/climatic conditions/location
-system receives stormwater from 16.2km² light
industrial and residential catchment
-average annual rainfall is 461mm
-average annual runoff is 1520000m³y¯1
-system designed to treat 1100000m³y¯1 per year
-3 stages of the system: weir diverts stormwater into an
in-stream basin (50,000m³), then pumped at
~3000m³h¯1 to holding storage until capacity
(50000m³), then gravity fed to the constructed wetland
(25000m³)
-Wetland is diamond shaped and covers 0.11km; water
depth 30-60cm
-Wetland vegetated with reeds
- inlet and outlet at apexes
-minimum holding time of 7days
-During the study volume = 21000m³; average depth =
0.2m
-temperatures 3.8-32.9°C for air; 13.3-15.6°C for water.
- This study was initiated to provide
quantitative data on the effectiveness of
VFSs on removing
sediment and nutrients as influenced
by: (1) soil and geomorphic conditions,
(2) type of vegetation,
and (3) hydrologic features of site and
various runoff events.
- two sets of plots and each set contains
a field edge collector
and 4.2 m and 8.4 m grass filter plots.
- Experiment undertaken in Piedmont and Coastal Plain
of North Carolina
- The Piedmont site is in Wake County on NCSU
Research Farm Unit 9 which has topography and soils
typical of the lower Piedmont.
-The Coastal Plain site is on the Cunningham Research
Farm near Kinston, North Carolina. This site has
topography and Norfolk-Rains
Soil Association typical of the middle and lower Atlantic
Coastal Plain.
- Both sites occupy gentle valley slopes that grade
downward to a concave foot-slope in a riparian
area.
- The soils at the Piedmont site are on a dissected high
terrace and are within the State Soil Series.
- The Piedmont site occupies a gentle linear slope with
an average slope of 3.6% in the cultivated
areas and slightly steeper slopes in the grass filters
(Table 1). The wooded filter plots are very steep.
-At the Coastal Plain site, the soils in the cultivated area
are within Norfolk and Goldsboro Soil Series.
-The soils in alluvium in the Coastal Plain riparian filters
Results
33–51% for diuron and 20–60% for simazine.
- The maximum daily flow through the wetland
based on volumetric calculations corresponds to a minimum
hydraulic residence time of 10 d, compared to an engineered
design
retention time of 7 d.
- only simazine was detected in composite sampling, however,
atrazine, simazine and diuron were detected in passive
sampling
- wetland systems have limitations such as the large land area
needed for treatment in comparison with engineered treatment
processes.
- moderate removal observed for the three herbicides
suggests that they may be adsorbed onto the organic
sediment and biofilms of the constructed wetland.
- organic carbon present in the wetland provides sorption sites
for the simazine removal
- biodegradation may require more than several days to
remove most of the herbicides
At both the Piedmont and Coastal Plain sites, runoff volumes
from the field edge collectors were generally reduced as they
passed through the grass buffers.
- natural grass (crab grass) initially present on the buffers were
not as effective in reducing runoff volume as the fescue sod
planted later.
-The riparian vegetation plots reduced runoff volumes for most
of
the smaller storm events.
-for the larger storm events the runoff volumes from the
riparian areas were often large and comparable to the field
edge runoff
- All filters were effective in removing sediment from the
agricultural runoff up to 80-90%
- Neither the grass buffers nor the riparian areas were very
effective in removing phosphorus in solution
(orthophosphate).
-Removal of total phosphorus and total Kjeldahl nitrogen was
very variable between storms and between plots. However,
approx 50% of these constituents were
removed in the 4 m filters.
-The 8 m filters were more effective in removing all potential
38
Reference
Experimental design
Patty, L., Real, B., and
Gril, J.J. (1997). The
use of grassed buffer
strips
to
remove
pesticides, nitrate and
soluble phosphorous
compounds from runoff
water.
Journal
of
Pesticide Science 49,
243-251
-experimental sites consisted of 4
cultivated plots (250m²) bordered with a
plastic sheet
- 20m wide grassed buffer strip
(ryegrass) installed at lower edge of
plots
-runoff from plots collected by
galvanized metal sheet, drained into a
tank after filtration through 0, 6, 12, or
18m of grassed strip
(Patty et al. 1997)
Hydrology/climatic conditions/location
are within the
range of the Myatt series.
- The Coastal Plain site occupies a gentle linear to
concave head slope. The cultivated area has an
average slope of 1.9 percent.The grass filters have
slopes less than 1.5% and slopes in the riparian filters
are less than 1%.
- Piedmont and Coastal Plain study areas have a
sloping cultivated area 27.4 m wide and 36.6 m long./
Results
contaminants from the runoff water but doubling the filter
length almost never doubled the grass or riparian filter
effectiveness for removal of any constituent.
-Experiments on grassed buffer strips conducted since
1993 by ITCF (Institut Technique des Cereales et des
Fourrages) at three research farms (La Jailliere, Bignan,
Plelo) – located in Brittany (France)
- Literature data and conclusions from previous work showed
that grassed buffer strips are effective in restricting pollutant
transfer in runoff; those with widths of 6, 12 and 18 m reduced
runoff volume by 43 to 99%, suspended solids by 87 to 100%,
lindane losses by 72 to
100% and loss of atrazine and its metabolites by 44 to 100%.
-More than 99% of
isoproturon and 97% of diflufenican residues in runoff were
removed by buffer
strips.
-Nitrate and soluble phosphorus in runoff were reduced by 47
to 100% and by 22 to 89%, respectively.
-sowing perpendicular to the slope seemed to be beneficial
in reducing pesticide content in runoff.
39
Reference
Experimental design
Hydrology/climatic conditions/location
Patzold, S., Klein, C.,
and Brummer, G.W.
(2007). Run-off
transport of herbicides
during natural and
simulated rainfall and its
reduction by vegetated
filter strips. Soil Use
and Management 23,
294-305
-aim of this study was to evaluate the
reduction of herbicide
discharge from arable land by different
vegetated filter strips. The experiments
were conducted with both natural and
simulated rainfall using three herbicides
with contrasting
physico-chemical properties during a 3year period
-study was conducted with the
commercial herbicide Stentan,
containing the active
ingredients metolachlor, terbuthylazine
and pendimethalin
-measurements were carried out from 1997 to 1999
under normal agricultural conditions in Velbert-Neviges,
a hilly, loess covered region of North Rhine-Westphalia,
Germany.
-The site is located in the Rhenish Massif at a height of
170 m above sea level.
-The long-term mean annual precipitation
is 1072 mm. Annual rainfall over study period was 988
mm (1997), 1309 mm (1998) and 1236 mm (1999).
-contour-cultivated field with a slope of 10% was
cropped with maize each year
-soil is typical of the Rhenish Massif and is classified as
a Eutric Stagnic Cambisol. The Ap and Bgw1 horizons
are formed from a mix of loess and weathered Lower
Devonian silt and clay shales. The Bg and Cg horizon
derived from weathered clay shales. Due to the silty
topsoil and the restricted permeability of the subsoil,
these soils are at risk of soil erosion (Kehl et al., 2005
-field had a pH (CaCl2) of 5.6 and an organic carbon
content of 17.0 g kg)1
(Patzold et al. 2007)
-Stentan was applied with a
conventional field sprayer at a rate of 6
L ha)1
-run-off suspensions were collected at
the
downhill edge of four test plots to
examine herbicide transport
-field was cultivated
and sown with maize, but a 12 m wide
margin received no fertilizer or
Results
-In a filter strip, several
processes may lead to retention of run-off and herbicides:
ponding (Melville & Morgan, 2001), infiltration (Boyd et al.,
2003), filtration and sedimentation of sediment-bound
pesticides (Abu-Zreig et al., 2004) and herbicide sorption on
soil and plants in the filter strip (Krutz et al., 2004).
-Metolachlor, terbuthylazine and pendimethalin were
transported
by run-off both in solution and adsorbed to eroded soil material
in suspension. The run-off suspensions leaving the vegetated
filter strips were not only substantially reduced in volume but
also in sediment content.
-concentrations of dissolved herbicides in run-off decreased
during passage across the strips
-Cultivated, but herbicide-untreated 12-m-wide strips of
conservation
headland (CH12) were less efficient in reducing herbicide
output than 6-m grass strips, due to the patchy
plant cover in CH12
-12-m grass strips (GF12) gave the most effective protection
against herbicide loss in surface run-off.
-filter strip width and extent of cover determine the
40
Reference
Perera, A., Burleigh,
J.R., and Davis, C.B.
(1999). Movement and
retention of propanil N(3,4-dichlorophenyl)
propanamide in a
paddy-riverine wetland
system in Sri Lanka.
Agriculture, Ecosystems
and Environment 72,
255-263
(Perera et al. 1999)
Pinho, A.P., Morris,
L.A., Jackson, C.R.,
White, W.J., Bush, P.B.,
and Matos, A.T. (2008).
Contaminant retention
potential of forested
filter strips established
as SMZs in the
piedmont of Georgia.
Journal of the American
Water
Resources
Association
44(6),
1564-1577.
(Pinho et al. 2008)
Experimental design
herbicides to allow the growth of weeds
-3,6, &12m wide strips sown with a
standard seed mixture for pasture
(Festuca pratensis, Phleum pratense,
Festuca
rubra, Lolium perenne, Poa pratensis,
Trifolium repens) at 35 kg ha)1.
-objective to examine fate of propanil in
rice paddy – drainage channel wetland
ecosystem by documenting changes in
concentration over time and space in
paddy soil and water, in water and
substrate of adjacent wetlands receiving
runoff from the paddy; in tissues of 2
wetland macrophytes.
-sampling undertaken in wet season of
1993-1994 and 1994 dry season.
-paddy sampling in a 1.2ha paddy near
lower end of 200ha drainage area
-water enters paddy from a 1.5m wide
unlined feeder cannal, exits into
drainage channel
-wetland samples collected from
drainage channel downstream of water
outfall.
-plot scale overland flow experiments
were conducted to evaluate the
efficiency of natural forested filter strips
as streamside management zones
(SMZs), for retaining phosphorous,
atrazine and picloram transported in
runoff.
-5 slope classes: 1-2, 5-7, 10-12, 15-17,
and 20-22%
-2 cover conditions: undisturbed forest
floor and forest floor removal by raking
-summer dry and winter wet soil
moisture conditions
-surface flow collected at 0,2,4,6,&10m
within filter strip
-2 laboratory adsorption experiments on
Hydrology/climatic conditions/location
Results
performance of filter strips for the reduction of herbicide
transport in run-off
-12-m grass filter strips provided an almost optimal reduction
of erbicide
output from arable fields via surface run-off
-rice cultivation in Eastern Sri Lanka
-agricultural development area 20km east and
southeast of Polonnaruwa
-area is low lying, poorly drained, dominated by paddy
cultivation; forest-pasture; and wetlands
-21,000 families cultivate 20,625ha of paddy during the
wet (Nov-Feb) and dry (May-Oct)
- irrigation water flow from reservoirs through a network
of canals to paddies, exits into adjacent drainage
channels of riverine wetlands.
-Propanil detected in paddy soil, paddy and wetland water
samples up to 14days after treatment
-Propanil not detected in wetland substrate
-Propanil in high concentrations in leaf and stem tissues of
edible plants (Ipomoea aquatic & Limnocharis flava) during the
wet season
-Experiment located in the Piedmont of Georgia in the
U.S. Southeast is a timber producing region and
metropolitan area
-Vegetation:
-On average, a 10 m length of forested SMZ with an
undisturbed forest floor reduced initial solution concentration
of total dissolved P by 51%, orthophosphate P by 49%,
atrazine by 28%, and picloram by 5%.
-Percentages of mass retention through infiltration of water
plus concentration reductions in runoff were 64% for total
dissolved
P, 62% for orthophosphate P, 47% for atrazine, and 28% for
picloram for undisturbed forest floor conditions.
-Lower retention occurred following forest floor removal,
particularly for P.
-Average dissolved P retention was 16% lower following forest
floor removal.
-For undisturbed sites, differences in retention were more
closely related to forest floor depth than to slope or antecedent
soil moisture.
41
Reference
Poletika, N.N., Coody,
P.N.,
Fox,
G.A.,
Sabbagh, G.J., Dolder,
S.C., and White, J.
(2009). Chlorpyrifos and
atrazine removal from
Experimental design
herbicides
-investigated the effect of drainage area
ratio (i.e., the ratio of field area to VFS
area) and flow concentration (i.e.,
uniform
versus concentrated flow) on pesticide
removal efficiency of a VFS and used
Hydrology/climatic conditions/location
-Experimental site located in western Sioux Country,
Iowa on a loess-covered bench
-Soil moderately erodible Galva silty-clay loam
-Slopes uniform, ranged from 5-5.5%
-plots constructed by excavating a ditch at downslope
end of each VFS plot, retaining wall installed.
Results
-These results indicate that
forested SMZ filter strips provide a significant measure of
surface water protection from dissolved P and herbicide
delivery to surface water
-Table 3: Measured change in contaminant concentration
expressed as Concentration in overland flow leaving 10-m
wide forested filter strips and total mass retention estimated
from concentration reduction and retention through water
infiltration.
-Retention of atrazine has been shown to be increased by filter
strip length
-dissolved contaminants and colloid-bound contaminants
initially retained by water infiltration can continue to move to
streams as subsurface flow through macropores
-forest vegetation and the microbially active layer of forest
floor it produces has shown to increase herbicide degradation
rates
-reductions in solution concentrations and mass retention of P
and 2 herbicides were observed for simulated flow within 10m
wide forested filter strips across a range of slopes and organic
horizon conditions
-forest floor depth appeared to be important in affecting
retention of dissolved contaminants
-10m wide forested SMZ filter strip with an undisturbed O
horizon provides a measurable degree of surface water
protection from dissolved P and herbicide delivery even in
extreme runoff events
-Pesticide removal efficiency of VFS for uniform flow
conditions (59% infiltration; 88% sediment removal) was 85%
for chlorpyrifos and 62% for atrazine.
- Flow concentration reduced removal efficiencies regardless
of drainage area ratio (i.e., 16% infiltration, 31% sediment
removal, 21% chlorpyrifos removal, and 12% atrazine
42
Reference
runoff by vegetated filter
strips: Experiments and
predictive
modeling.
Journal
of
Environmental Quality
38, 1042-1052
(Poletika et al. 2009)
Polyakov, V., Fares, A.,
and Ryder, M.H. (2005).
Precision
riparian
buffers for the control of
nonpoint
source
pollutant loading into
surface water: A review.
Environmental Reviews
13, 129-144
(Polyakov et al. 2005)
Experimental design
these data to provide further field
verification of a recently proposed
numerical/empirical modelling
procedure
for predicting removal efficiency under
variable flow conditions
-Runoff volumes were used to simulate
drainage area ratios of 15:1 and 30:1.
-Flow concentration was investigated
based on size of the VFS by applying
artificial runoff to 10% of the plot width
(i.e., concentrated flow) or the full plot
width (i.e., uniform flow).
-Artificial runoff was metered into 4.6-m
long VFS plots for 90 min after a
simulated rainfall of 63 mm applied over
2
h. The artificial runoff contained
sediment and was dosed with
chlorpyrifos and atrazine.
-Review Paper
-Overview of current level of research
on riparian buffers and importance of
spatial variability of local conditions on
their performance.
-Presents approaches for precision
buffer design, practical implementation,
highlights directions for future
development
Hydrology/climatic conditions/location
-VFS installed in 1994, 90% Bromus inermis, 10%
bluegrass. This was fertilized, watered and mowed to
10cm height until May 1995
-Study period of 9 days and simulated rainfall
Results
removal).
-Without calibration, the predictive modeling based on the
integrated VFSMOD and empirical hydrologic based pesticide
trapping efficiency equation predicted atrazine and chlorpyrifos
removal efficiency under uniform and concentrated flow
conditions.
-Consideration for hydrological processes is required to
adequately predict VFS pesticide trapping efficiency.
-VFS performance can decline when flow volume increases,
reducing infiltration and removal of dissolved constituents from
runoff (Arora et al., 1996)
Literature
-Sediment retention
-Phosphorous
-Nitrogen
-Relief characteristics
-Infiltration
-Subsurface flow and storage capacity
-Research has proved effectiveness of vegetative buffers in
reduction of sediment and nutrient movement from field to
streams at the scale of INDIVIDUAL TRANSECTS. (Sediment
retention rations 45-98%).
-Variety of vegetation types and buffer widths report P removal
rates from surface runoff 60-90%.
-Current lack of understanding of buffer effectiveness at
LANDSCAPE SCALE
-Usually only a small fraction (9-18%) of total buffer area
contacts the runoff water, which may reduce trapping
efficiency from the potential 41-99%, to the actual 15-43%.
-Discrepancies between potential and actual efficiency include
spatial variability, erosion rates, soil properties, non-point
pollution sources, distance to watercourses, topography etc.
-Use of various topographic indicators such as area, slope
wetness, erosion proven to be useful tools in precision buffer
delineation.
-precision buffer planning required. Identify potential
pollutants, design buffer to counteract those pollutants
-Current lack of quantitative methods, capable of evaluating
field runoff patters and impacts on riparian buffer effectivess
43
Reference
Popov, V. H. and P.
Cornish
(2006).
"Atrazine tolerance of
grass species with
potential for use in
vegetated filters in
Australia." Plant and
soil 280(1): 115-126
(Popov and Cornish
2006)
Popov, V.H., Cornish,
P.S., and Sun, H.
(2006).
Vegetated
biofilters: The relative
importance of infiltration
and adsorption in
reducing loads of watersoluble herbicides in
agricultural
runoff.
Agriculture, Ecosystems
and Environment 114,
351-359
(Popov et al. 2006)
Experimental design
Hydrology/climatic conditions/location
-This study looks at grass species
tolerance to herbicide atrazine.
-Grass species intended for biofiltering
included: Pennisetum clandestinum,
Stipa aristiglumis, Themeda australis
and Danthonia.
-Liverpool Plains, NSW, Australia.
-Soil type for experiment two: Vertosol (clay) soil from
the Liverpool Plains.
-studied the potential for vegetated
biofilters to reduce loads of atrazine and
metolachlor in runoff water in grassed
filter strips (1.25m x 4m).
-7 treatments, replicated 2x
-1 set of treatments had 30mm
simulated rain applied by sprinklers at
60mm h¯1 to partially close cracks,
these treatments then received runon of
20,40,60 or 80mm depth
-remaining treatments received 10mm
simulated rainfall (to precede runoff),
then these treatments received 80,160,
320 and 800mm of runon
-Runoff with known concentrations of
the 2 herbicides (Atrazine „Nutrazine‟
500g a.i. L¯1, and metolachlor „Dual‟
720g a.i. L¯1 at concentrations of
100µmg a.i. L¯1) and sediment (5g
L¯1) was introduced to the plots
-runoff volume and pollutant
concentrations were measured
-load reduction partitioned between
infiltration and reduced concentration
-Experiment aims a) quantify potential
effectiveness of grassed biofilters under
-location is the Blackville watershed of the Liverpool
Plains, NSW Australia
-cracking vertisol soil
-Soils are rich in organic carbon (3-4%), N (0.35%),
available P (53mg kg¯1), pH 7.2
-experiment undertaken a long dry spell, to allow soil
profile to dry and crack
-14 plots over 150m grassed waterway, established in
1995 to retain and filter herbicides washed from
adjacent cropping land
-herbicides are applied pre and post-emergence in Nov
annually in this watershed
-Grass species included kikuyu grass (Pennisetum
clandestinum) and scattered native wallaby grass
(Danthonia spp.)
together covering "80% of the area, as well as
Bermudagrass (Cynodon dactylon) and other grasses
and legumes covering "20% of the area.
-maximum capacity for infiltration at this site was
calculated to be 224 mm, assuming drying of the root
zone to 120 cm
depth.
-Average slope of plots was 5.3% ranging from 2.8% to
9.1%.
-grass height at time of experiment was 15-20cm
Results
-Consideration of economic viability required
-Development of new indexes to ID hot spots where sediment
and pollutants might be delivered to stream channel is
required.
-Each grass species in the study were tolerant in „normal‟ soil
conditions. P. clandestinum and T. australis showed greatest
tolerance to high atrazine doses. P. clandestinum was the
most tolerant to atrazine regardless of period or number of
doses.
-In soil, it is presumed microbial activity uses the available
atrazine leaving insufficient residue for plant toxicity.
-Popov (2005) field scale data from runoff monitoring Liverpool
Plains suggested that biofilters could substantially reduce
pesticide concentrations in agricultural runoff in commercial
conditions
-„runon‟ = simulated runoff (to plots)
-Biofilters reduced total loads by 40-85% for atrazine; 44-85%
for metolachlor; 57-93% for sediment
-runon depths of <80mm reduced herbicides by ~25-49%
(atrazine) and ~30-61% (metolachlor), despite moderate
solubility of atrazine (~33mg L¯1) and high solubility of
metolachlor (520mg L¯1)
-sediment loads reduced at runon depths of up to 320mm
-infiltration was the only mechanism that significantly reduced
herbicide loads at runon depths between 160 and 800mm
-Hydrological analysis of 7 runon treatments
-Reduction in pollution concentrations
44
Reference
Experimental design
soil and hydrology conditions of
Liverpool Plains; b) evaluate relative
importance of adsorption and infiltration
re. reduction loads of atrazine and
sediment in runoff; c) identify gaps in
knowledge
-experimental set up..
Hydrology/climatic conditions/location
Results
-The study showed that biofilters were still effective in
conditions of intense runoff from cropland (runon depths of
160, 320, 800mm over 0.7 and 0.8h)
-study found that adsorption of chemicals to vegetation and
soil organic matter is cruicial with low runon depths
-biofilters should be established in accordance with watershed
scale, soil and veg conditions, rainfall and pollutant properties
Pot, V., Simunek, J.,
Benoit, P., Coquet, Y.,
Yra, A., and MartinezCordon, M.J. (2005).
Impact
of
rainfall
intensity
on
the
transport
of
two
herbicides
in
undisturbed
grassed
filter strip soil cores.
Journal of Contaminated Hydrology 81, 63-88
(Pot et al. 2005)
Prosser
IP
(1999)
-study focuses on the identification of
the main flow and transport
mechanisms in a
grassed buffer strip soil and on the fate
of two herbicides, isoproturon and
metribuzin
-Two series of displacement
experiments with isoproturon and
metribuzin herbicidesDisplacement
were conducted at steady-state flow
under unsaturated
conditions
-one-dimensional transport model
HYDRUS-1D (S ˇ imlnek et al., 1998,
2003) was used to
identify and quantify different physical
and chemical non-equilibrium transport
processes
acting in the grassed soil.
-experimental site of ARVALIS at La
Jaillie`re in the western part of France (Loire-Atlantique
-20-m-wide 10year old grassed strip,
planted with perennial rye-grass (Lolium perenne) in
1992, cut twice a year.
-The soil is a hydromorphic silt loam (24% clay, 40%
silt, 36% sand) developed on altered schists of the
Massif Armoricain.
-A perched aquifer often forms during the winter period
at a depth of 25–60 cm and can occasionally reach the
soil surface
-Two undisturbed soil cores (14-cm i.d. and 30-cm
height) were sampled in June 2002
from the soil surface layer
-Several rainfall intensities (0.070, 0.147, 0.161, 0.308
and 0.326 cm h!1) were used
- A summary of results of sediment
-Study site (one of two): Johnston River, far north
-Chemical non-equilibrium transport of herbicides was found at
all rainfall intensities
-Measured flow properties and leaching chemical properties
-for both herbicides the mass recovery rate decreased with
decreasing velocity,
-residence times of herbicides increased as velocity
decreased, therefore allowing more sorption and degradation
to occur inside soil column
-experimental Br BCTs and their descriptive/numerical
analyses suggested 2 contrasted physical non-equilibrium
processes, dependant on rainfall intensity
-highest rainfall intensity: multiple porosity domains and
multiple permeabilities preferential flow were probably active
a) rapid flow through macropore pathways; b) slower flow
through a mesoporosity; c) no-flow in remaining micropores
-lower rainfall intensities, macropore flow was not active
anymore
-non-equilibrium chemical transport processes occurred for all
velocities, and both herbicides, and degree of non-equilibrium
sorption increased with velocity.
- Hill slope erosion dominates sediment yield far in the north of
45
Reference
Identifying priorities for
riparian
restoration
aimed at sediment
control. In 'Second
Australian
Stream
Management
Conference'. Adelaide
pp. 511-516
Experimental design
budgets from 3 Australian
environments. Identification of whether
sediment comes from channel or
hillslope sources.
Hydrology/climatic conditions/location
Queensland.
Qiu Z, Prato T (1998)
Economic evaluation of
riparian buffers in an
agricultural watershed.
Journal of the American
Water
Resources
Association 34, 877890.
-An evaluation of the most cost effective
spatial pattern of farming systems for
improving water quality through riparian
buffers.
-Combined experimental data and
simulated water quality are used to
assess the water quality benefits of
riparian buffers.
-Considers herbicide atrazine.
-aim of study to quantify percentage
loss of six herbicides following
application to a roadside.
-herbicides were applied on 2 occasions
to a 16m length of road side
-automatic sampler collected runoff up
to 25mm of rainfall in a pot.
-analysed for atrazine, glyphosate,
diuron, oxadiazon, oryzalin and
Isoxaben
-Table: herbicide properties and
application rates
-Study area: Goodwater Creek watershed, north central
Missouri.
-Soil type: Mexico silt loam, Mexico silty clay loam and
Putnam soil.
-Principal agricultural activity: crop production.
-Results strongly support efforts that encourage farmers to
develop and maintain riparian buffers adjacent to streams.
-16m asphalt rd with concrete kerb on the A6, 200m
south of Cavendish Bridge at Shardlow, Derby UK
(112km² catchment)
-all herbicide concentrations had rapid declines throughout the
first rain event following application,
-majority of loss occurring within first 10mm of accumulated
rainfall
-compounds of high solubility and low Koc produced highest
peak concentrations
Ramwell, C.T., Heather,
A.J., and Shepherd,
A.J. (2002). Herbicide
loss
following
application
to
a
roadside.
Pest
Management Science
58:695-701
(Ramwell et al. 2002)
Rankins, A.Jr., Shaw,
D.R., & Boyette, M.
-to determine the effectiveness
of several grasses as filter strips for
-Field studies conducted in 1996,1997,1998
- 127-d sampling
Results
Queensland
-Graph (above): concentrations of atrazine and diuron in
drainflow during first 25mm of accumulated rainfall
-application rate may be an important factor in determining
herbicide loss for compounds of low solubility and moderate
Koc
- Big bluestem, eastern gamagrass, switchgrass, and tall
fescue reduced total runoff
46
Reference
(2001). Grass filter
strips for reducing
herbicide losses in
runoff. Weed Science
49(5), 647-651
Experimental design
reducing sediment and herbicide losses
in runoff
- Mississippi Agricultural and Forestry
Experiment Station Black Belt Branch
near Brooksville M,S
(Rankins et al. 2001)
Rankins, A.Jr., & Shaw,
D.R.
(2002).
Comparison
of
fluometuron sorption to
soil from a filter strip
and cropped field.
Weed Science 50, 820823
-laboratory experiment conducted to
compare the adsorption and desorption
of fluometuron between two soils, one
collected from an eastern gamagrass
filter
strip and the other from a cropped field.
(Rankins et al. 2002)
Rankins, A.Jr., Shaw,
D.R., & Douglas, J.
(2005). Response of
perennical
grasses
potentially used as filter
strips
to
selected
postemergence
herbicides.
Weed
Technology 19, 73-77
(Rankins et al. 2005)
-Field experiments
were conducted in 1997 and 1998 to
evaluate the response of eastern
gamagrass, switchgrass, and
tall fescue to postemergence
drift and registered rates of glyphosate
and paraquat in mid-April and
clethodim, fluazifop-P,
glyphosate, MSMA, pyrithiobac,
quizalofop-P, and sethoxydim in early
June.
- plot size was 1.5 by 1.5 m
- experimental design was a
randomized complete block with four
replications
- herbicides evaluated
Hydrology/climatic conditions/location
Period
- Brooksville silty clay (fine montmorillonitict, hermic
Aquic
Chromudert 3; .0% slope, 3.2% organic matter,and pH
6.3
in the Ap horizon
- low saturated hydraulic conductivity( less than 1.5
to 5 mm h-1)
- racking during
dry periods, which can temporarily facilitate infiltration
- In each year, natural rainfall was supplemented by
simulated rainfall to
ensure runoff at timely interval
- Soil was collected in an area cropped with cotton and
in an adjacent area containing a narrow (0.6 m), 3-yrold
eastern gamagrass filter strip
-soil type was a Brooksville
silty clay (fine montmorillonitic, thermic Aquic
Chromudert).
-The soil in the cropped area contained 2.7% organic
matter, and the pH was 6.9
-soil in the filter strip area contained 3.5% organic
matter and had a pH of
6.7.
- Field studies were established in 1997 and 1998 at the
USDA Natural Resources Conservation Service Jamie
Whitten Plant Materials Center near Coffeeville, MS,
and the Black Belt Branch Experiment Station near
Brooksville, MS,
- soil types were a Grenada silt loam (finesilty, mixed,
thermic Glossic Fragiudalfs; 2.0% organic matter, and
pH 5.3 in Ap horizon) and an Oaklimeter silt loam
(coarse-silty, mixed, thermic Fluvaquentic
Dystrochrepts; 1.3% organic matter, and pH 5.3 in Ap
horizon) at Coffeeville, and a Brooksville silty clay (fine
montmorillonitic, thermic Aquic Chromuderts; 3.0%
organic matter, and pH 6.6 in Ap horizon) at Brooksville
Results
volume by at least 55, 76, 49, and 46%, respectively.
- each perennial grass filter strip investigated reduced total
sediment loss in
surface runoff by at least 66%.
-All four species reduced total fluometuron loss in
runoff at least 59%.
-Big bluestem and eastern gamagrass reduced norflurazon
loss in runoff 63 and 86%, respectively
- Fluometuron adsorption to soil collected from the filter strip
was higher than to soil collected from the cropped field.
- Kd values for fluometuron ranged from 1.9 to 3.6 for soil from
a cropped area, compared
with 2.9 to 5.3 for soil from the filter strip, indicating a weak to
moderate binding affinity for fluometuron
- total fluometuron desorbed ranged from 48 to 79% of that
adsorbed, most of which (50 to 59% of the total amount
desorbed)
occurred during the first desorption cycle with both soils
- Approximately 11% less
fluometuron desorbed when a filter strip was present.
-filter strip implementation will not simply involve establishment
and maintenance
- inability of these perennial grasses to recover from an
accidental overspray
or drift, within the year of the event
47
Reference
Rasiah V, Armour JD,
et al. (2010) Nitrate
import–export dynamics
in
groundwater
interacting with surfacewater in a wet-tropical
environment. Australian
Journal
of
Soil
Research 48, 361-370.
Reungsang, A., T. B.
Moorman, et al. (2001).
"Transport and fate of
atrazine in MidWestern
riparian buffer strips."
JAWRA Journal of the
American
Water
Resources Association
37(6): 1681-1692.
Reddy, K.N., Locke,
M.A., and Bryson, C.T.
(1994). Foliar washoff
and runoff losses of
lactofen, norflurazon,
and fluometuron under
simulated
rainfall.
Journal of Agricultural
Food Chemicals 42,
2338-2343
(Reddy et al. 1994)
Experimental design
were clethodim (26 and 105 g ai/ha),
fluazifop-P
(39 and 158 g/ha), glyphosate (280 and
1,120 g/ha),
MSMA (280 and 1,120 g/ha), paraquat
(176 and 706 g/
ha), pyrithiobac (17 and 70 g/ha),
quizalofop-P (14 and
56 g/ha), and sethoxydim (70 and 280
g/ha).
-Investigation into a link between nitrate
in leachate, groundwater and drain
water.
-Assessment into the hazard/risk of the
concentrations against the trigger
values proposed for sustainable health
of different aquatic ecosystems.
-Samples collected from a banana farm
in the wet tropical Tully River.
Hydrology/climatic conditions/location
Results
-Study site: Tully River catchment, North-East
Queensland.
-Association between leachate volume and solute
concentration, and the solutes in the leachate and those in the
groundwater and drain water suggest unused/under-utilized
nitrate leaching below the root-zone perculating into the
groundwater.
-This study analyzed atrazine and
bromide fate in switchgrass riparian
buffer strips (RBS) with adjacent
agricultural land use of either crop
rotation (corn and soybean) or grassalfalfa and 3 soil ages (3, 5 and 9 yrs).
-Bear Creek watershed, near Roland, Iowa.
- Soil types: Clarion (fine loamy, mixed, mesic Typic
Haploaquoll) and Coland (fine loamy, mixed, mesic
Cumulic Haploaquoll).
-Simulation of a 4cm rainfall event that would be
predicted to occur once every 2.1 yrs in study area
(Iowa).
-Perennial grass est. may change the ability of the soil to
infiltrate water and atrazine.
-Soils of young age (<5yrs) provide limited infiltration of
atrazine.
-Link between adjacent land use and atrazine removal was
unclear.
- Plants were sprayed with lactofen at
0.4 kg of ai ha-l and subjected to 2.5 cm
of rainfall in 20 min at 1 and 24 h after
application
- Runoff losses of lactofen, norflurazon
and fluometuron in 2.24 m x 1.22 m x
0.25 m fiberglass runoff trays with 1.1%
slope were also studied
- A rainfall of 2.5 cm in 20 min at 24
HAA generated 0.8 cm
of runoff and contained 3.2% of applied
lactofen
- Bosket sandy loam soil (fineloamy,
mixed, thermic Mollic Hapludalfs: 43% sand, 48% silt,
9% clay, 1.51% organic matter, pH 5.45).
- rainfall simulator reproduced droplet size, fall velocity,
and kinetic characteristics similar to those of natural
rainstorms.
- At 1 HAA, in both species,
over 97% of lactofen was washed off from foliage. At 24 HAA,
lactofen washoff ranged from 51% to 82% in both species.
- lactofen loss in runoff was reduced by 94% with a cover crop
of Italian ryegrass (Lolium multiflorum Lam.) and crimson
clover (Trifolium incarnatum L.1
- Norflurazon and fluometuron losses in runoff from no-crop
residue trays were 4.4% and OB%, respectively, when a
rainfall of 3.8 cm in 30 min was applied at 24 HAA.
- Lactofen is vulnerable to foliar washoff
- The presence of a crop residue can greatly reduce
movement of norflurazon and fluometuron in runoff.
48
Reference
Reichenberger,
S.,
Bach, M., Skitschak, A.,
& Frede, H.G. (2007).
Mitigation strategies to
reduce pesticide inputs
into ground and surface
water
and
their
effectiveness;
A
Review. Science of the
Total Environment 384,
1-35
(Reichenberger et al.
2007)
Experimental design
-runoff trays; fiberglass
trays were 224 cm long, 122 cm wide,
and 25 cm deep with impermeable
bottoms.
-Review of current knowledge on
mitigation strategies to reduce pesticide
inputs into surface water and
groundwater, and
their effectiveness when applied in
practice
- measures considered are
recommended for implementing at the
farm and catchment scale.
-recommendations for modelling are
provided using the identified reduction
efficiencies
-180 publications reviewed
Hydrology/climatic conditions/location
Results
-effectiveness of grassed buffer strips located at the lower
edges of fields has been demonstrated, however variable
-Riparian buffer strips are less effective than edge-of-field
buffer strips in reducing pesticide runoff and erosion inputs
into surface waters
-Constructed wetlands are promising tools for mitigating
pesticide inputs via runoff/erosion and drift into surface waters,
but their effectiveness has not been demonstrated for weakly
and moderately sorbing compounds
-Subsurface drains are an effective mitigation measure for
pesticide runoff losses from slowly permeable soils with
frequent waterlogging
-pathways drainage and leaching, requires application rate
reduction, product substitution and shift of the application date
to remain feasible
-Point-source inputs can be mitigated by increasing
awareness of farmers with regard to pesticide handling and
application, and use of BMPs
-
49
Reference
Experimental design
Hydrology/climatic conditions/location
Results
-more mitigation measures
(and literature on mitigation) available for the pathways
runoff/erosion and spray drift than for drainage and
leaching
Robinson, C.A.,
Ghaffarzade, M., and
Cruse, R.M. (1996).
Filter strip Vegetative
effects on sediment
concentration in
cropland runoff. Journal
of Soil and Water
Conservation 51(3),
227-230
(Robinson et al. 1996)
-collector-sample splitter to collect
representative runoff subsamples.
-study areas on 7% and 12% grades to evaluate VFS
effects on sediment concentration, runoff volume, and
soil loss from an 18.3m continuous fallow strip.
-placed collectors at six intervals within the
Bromegrass filter strip and recorded data from 13
rainfall events
-Fayette (fine-silty, mixed, mesic Typic Hapludalfs) silt
loams in northeast Iowa
-soils were 77% silt and 18% clay with 2% organic
matter
-Bromegrass (Bromus inermis
L.) was the dominant species in the filter
strip, though a few alfalfa (Medicago sativa
L.) tillers (< 10%) and some orchardgrass
(Dactylis glomerata L.) tillers were
-initial 3.0 m of the VFS
removed more than 70% of the sediment from runoff while 9.1
m of the VFS removed 85%
-Little decrease in sediment concentration was observed with
greater VFS widths
-12% grade had greater runoff and soil losses at all VFS
widths than the 7% grade
-VFS promoted infiltration, reduced runoff volumes, and
decreased runoff sediment concentration.
50
Reference
Experimental design
Rodgers, J.H.Jr, and
Dunn, A. (1992).
Developing design
guidelines for
constructed
wetlands to remove
pesticides
from agricultural runoff.
Ecological Engineering
1, 83-95
-research strategy for evaluating the
capability of constructed,
restored, and natural wetlands to
assimilate and process pesticides
associated with agricultural runoff from
croplands.
-provides a modelling and mathematical
approach
Hydrology/climatic conditions/location
present.
-southeastern United States
Results
(Rodgers et al. 1992)
Rose, M.T., Crossan,
A.N., and Kennedy, I.R.
(2008). The effect of
vegetation on pesticide
dissipation from ponded
treatment
wetlands: Quantification
using a simple model.
Chemosphere 72, 9991005
-a graphical model was constructed and
calibrated with site-specific and
supplementary data to describe the loss
of two pesticides, endosulfan and
fluometuron, from a vegetated and a
non-vegetated pond.
-The model system was used to
describe a ponded water storage
representative of those found on
Australian cotton farms: irrigation
tailwater or rainfall runoff was returned
to an uncovered
dam constructed from clay soil.
-We assume that dissolved and bound
pesticide residues
equilibrated during runoff prior to
-northern NSW,
-model
-Fluometuron dissipation resulted primarily from biofilm
reaction and photolysis, both of which were increased by
vegetation.
-greater photolysis under vegetation arose from faster
sedimentation and increased light penetration, despite
shading.
-The fate of the herbicide
atrazine has been well studied in different constructed
wetlands, with removal efficiencies ranging from 26 to 84%
over 8–30 d residence
times
-A similar range of removal efficiencies (26-84%)and/or halflives have been observed for the herbicides metolachlor,
simazine, diuron, and
fluometuron (Moore et al., 2001; Stearman et al, 2003; Rose
et al., 2006)
51
Reference
Rose MT, SanchezBayo F, et al. (2006)
Pesticide removal from
cotton farm tailwater by
a pilot-scale ponded
wetland. Chemosphere
63, 1849-1858.
Runes, H.B., Jenkins,
J.J., Moore, J.A.,
Bottomley, P.J., and
Wilson, B.D. (2003).
Treatment of atrazine in
nursery irrigation runoff
by a
constructed wetland.
Water Research 37,
539-550
Experimental design
returning to the storage
-A wetland was constructed in a cotton
farm and assessed for its potential to
remove pesticides from irrigation tail
water.
-Pesticides: diuron, fluometuron,
endosulfan and aldicarb.
-plant species planted in wetland:
knotweed, water primrose, water milfoil,
common rush, clubrush and cumbungi.
-To investigate the treatment capability
of a surface flow wetland, where
atrazine was introduced during
simulated rainfall events
-Treatment efficiency was evaluated as
the percent atrazine recovered (as
percent of applied) in the water column
at the wetland‟s outlet.
-The objectives of this study were (1) to
determine the
treatment capability of a surface flow
wetland used to remediate runoff
associated with irrigation (2) to
investigate
the processes involved in remediating
irrigation runoff.
Hydrology/climatic conditions/location
Results
-There is also evidence
that aquatic vegetation can accelerate pesticide removal
compared to open water systems. Due to the increased
capacity for plant/biofilm
sorption and subsequent immobilization, breakdown or uptake
of pesticides
-The model supports the view that sedimentation plays an
undervalued role in the removal process of different
contaminants
-results clearly indicated a role for the use of both vegetated
and non-vegetated wetland areas to increase the dissipation
and removal of pesticides from agricultural runoff.
-Study site: northern New South Wales, Australia.
-Partitioning onto sediment was found to be a considerable
sink for the insecticide endosulfan.
-The results demonstrate that macrophytes and algae can
reduce the persistence of pesticides in on-farm water.
-It is recommended that constructed wetlands are comprised
of both open water and vegetated zones to increase the
potential for complementary chemical, photolytic, microbial
and plant-mediated pesticide breakdown.
-wetland at a container nursery near Portland, Oregon
(Tualatin watershed)
-receives runoff from 2.4 ha of nursery land.
-soil was classified as a silt loam (10%
sand, 70% silt, and 20% clay), was slightly acidic (pH
6.03), and contained 2.13% organic carbon
-In 1996, each cell was planted with a variety of
wetland plants with the predominant species Typha
latifolia, or cattail. Subsequent plantings were
conducted in 1998 and 1999 with T. latifolia, resulting in
>75% plant coverage throughout the wetland cells.
-during a 7-d period ranged from 18–24% in 1998, and 16–
17% in 1999
-deethylatrazine (DEA) and deisopropylatrazine (DIA)
accounted for 13–21% of the initial application. Hydroxyatrazine (HA) was rarely detected in the water.
-Static water–sediment column experiments indicated that
sorption is an important mechanism for atrazine loss from
water passing through the constructed wetland.
-main pathways for atrazine degradation in water
and soil compartments are as follows: chemical or
microbial hydrolysis, followed by microbial degradation
in sediment [7] and sorption to sediment.
-Results of this study indicated that this constructed
wetland effectively reduced overall atrazine concentration
in container nursery irrigation runoff.
-Experiments conducted with wetland sediment columns
52
Reference
Experimental design
-Field experiments were conducted at a
constructed wetland consisting of five
sequential cells approximately
3mx40m
-Field experiments occurred from July
through September 1998 (experiments
1–3) and 1999 (experiments
4–6).
Hydrology/climatic conditions/location
Sabbagh, G.J., Gox,
G.A., Munoz-Carpena,
R. and Lenz, M. (2010).
Revised Framework for
Pesticide
Aquatic
Environmental
Exposure Assessment
that
Accounts
for
Vegetative Filter Strips.
Environment Science
and Technology, 44,
3839-3845.
Predictive model to determine required
VFS width. Combines predictions of
trapping with US EPA exposure model
(PRZM) which simulates pesticide fate
and transport.
USA, Illinois corn, multiple pesticides
Smaller VFS lengths had wider distributions in observed
pesticide trapping as compared to larger VFS lengths.
Nonlinear relationship between total water input (rainfall plus
runon) during a storm event & % pesticide reduction.
Differences in soil moisture affect reduction – lower reduction
with higher soil moisture content, ie. lower infiltration capacity.
Other factors controlling the range of responses for each filter
length are linked to the range of rainfall intensities and
durations that resulted in differences in sediment
characteristics (particle size distribution) in runon from the
source area.
For the 9.1-m long VFS, pesticide trapping or reduction was
generally greater than 60% unless the total water input (rainfall
plus runon) during a storm event exceeded 10 cm (Figure 2
below).
percent mass reduction of pesticide entering the pond does
not always correlate to an EEC percent reduction.
-Development and evaluation of an
-Study sites: various
-Filter strip width was not a statistically significant parameter in
(Sabbagh et al 2010)
Sabbagh, G., G. Fox, et
Results
indicated that sorption was a primary mechanism of atrazine
removal from the water column during field experiments.
53
Reference
al.
(2009).
"Effectiveness
of
vegetative filter strips in
reducing
pesticide
loading:
Quantifying
pesticide
trapping
efficiency." Journal of
Environmental Quality
38(2): 762-771.
Experimental design
empirical model with a foundation of
VFS hydrological, sedimentological and
chemical specific parameters.
-Data was pooled from a literature
review.
-A „phase distribution‟ parameter was
used in the model. This parameter was
the ratio of pesticide mass in dissolved
form to pesticide mass sorbed to
sediment, along with percent infiltration
percent sedimentation and the percent
clay content.
Hydrology/climatic conditions/location
-Soil type: Loam, clay, silty clay loam and silt loam.
-VFS vegetation: Brome grass, buffalo grass, oats,
bluegrass, switch grass and tall fesque.
Results
the empirical model.
- For low to moderately sorbing pesticides, the phase
distribution factor became statistically insignificant; for highly
sorbing pesticides, the phase distribution factor became the
most statistically significant parameter.
-For independent model evaluation datasets, the empirical
model based on infiltration and sediment reduction, the phase
distribution factor, and the percent clay content (STDD of
14.5%) outperformed existing filter strip width equations
(STDD of 38.7%).
-This research proposed a procedure linking a VFS hydrologic
simulation model with the proposed empirical trapping
efficiency equation.
-For datasets with sufficient information for the VFS modeling,
the linked numerical and empirical models significantly (R2 =
0.74) improved predictions of pesticide trapping over empirical
equations based solely on physical VFS characteristics.
Schmitt, T.J., Dosskey,
M.G. and Hoagland,
K.D. (1999). Filter Strip
Performance
and
Processes for Different
Vegetation, Widths and
Contaminants. Journal
of
Environmental
Quality, 28, 1479-1489.
Simulated runoff event on plots 3m x
7.5 or 15m), fine textured soil & 6-7%
slope.
Corn, grain sorghum and soybeans.
40 plots, 4 different vegetation types, 2
sizes.
Simulations – 25.4mm in 30 mins (1 in 1
yr event).
Applied known concentration of
contaminants.
University of Nebraska Agricultural R&D centre near
Mead (41deg 29‟N, 96deg, 30‟W).
Annual rainfall 690mm in storm events in spring &
summer.
Corn, grain sorghum and soybeans.
Well drained soils, silty clay loam
Filter strips 7.5 and 15m wide downslope greatly reduced
concentrations of sediment in runoff (76-93%) and
contaminants strongly associated with sediment inc total P
55-79%, permethrin 27-83%.
Less effect on primarily dissolved contaminants inc atrazine 5-43%, alachlor 10-61%, nitrate 24-48%, dissolved P 19-43%,
bromide 13-31%.
Dilution of runoff in rainfall accounted for most of reduction in
concentration of dissolved contaminants.
Infiltration substantially reduced mass of contaminants exiting
filter strips.
Doubling width doubled infiltration & dilution but didn‟t improve
sediment settling.
Young trees & shrubs in lower half made no difference.
Settling of sediment, infiltration & dilution are important
processes controlling performance of filter strips.
-Covers information on current sugarcane cropping systems
and improved sugarcane cropping systems.
(Schmitt et al., 1999)
Schroeder B, Calcino D,
et
al.
(2008)
'SmartCane principles
of best management
practice.' BSES limited,
CANEGROWERS and
-Babinda annual mean rainfall:3554mm
-Tully soil type (Babinda not specifically mentioned in
this report for soil type): Alluvial soils.
54
Reference
the
State
Queensland.
Experimental design
Hydrology/climatic conditions/location
Results
of
Schulz, R. (2001).
Rainfall-induced
sediment and pesticide
input from orchards into
the Lourens River,
Western Cape, South
Africa: Importance of a
single event. Water
Research, 35(8), 18691876.
(Schulz, 2001)
Schulz R (2004) Field
studies on exposure,
effects,
and
risk
mitigation of aquatic
nonpoint-source
insecticide
pollution.
Journal
of
Environmental Quality
33, 419-448.
Lourens River, South Africa
28.8mm rainstorm 1998
Adjacent areas are orchards
Concentrations of insecticides in stream were 1.5 mg/l
azinphos-methyl, 0.2 mg/l chlorpyrifos and 2.9 mg/l total
endosulfan (a, b, S) in the river itself. Respective average 1-h
pesticide levels associated with suspended particles were
1247, 924 and 12082 mg/kg, along with 980 mg/kg of
prothiofos.
Total suspended solids increased during runoff from 32 to
520mg/l.
Literature Review includes a section on
mitigation strategies including vegetated
buffers, wetlands.
Insecticides
Includes examples of vegetated buffers and constructed
wetlands being used for runoff mitigation.
Vegetated constructed wetland (134m x
36m)
dry weather conditions rainfall less than
2 mm/d
wet conditions between 2 and 35 mm/d
Measured concentrations at constructed
inlet and outlet.
Lourens River, Western Cape, South Africa (34°06′ S,
18°48′ E)
intensive farming, with orchards and vineyards in its
middle reaches.
Total catchment area ~ 92 km2
Annual mean rainfall 915 mm. Approximately 87% of its
35 × 106 m3 mean annual discharge occurs during the
winter months between April and October. Main soil
type is silty loam.
Reported dissolved insecticide concentrations are negatively
correlated with the catchment size and all concentrations of
>10ug/L were found in smaller scale catchments (<100km2).
Buffering capacity varies between pesticides (Mainstone &
Schofield, 1996).
Auerswald and Haider (1992) investigated copper containing
loss from hops and showed small particles that may be assoc
with large proportion of pesticide loss during small sized
erosion events are retained in grassed buffer strips only if at
least 30m wide.
France – runoff volume reduced 43-99% in grassed buffers 618m (Patty et al 1995, 1997).
In wet 15m wide buffer, isoproturon and pendimethanlin
retained 75 & 96% (Spatz et al 1997).
A range of results from wetlands as filters are presented in US
and Lourens R Sth Africa. Shows >99% retention in most
examples – generally assoc with sediment.
Total suspended solids, orthophosphate, and nitrate were
retained in the wetland in the proportions 15, 54, and 70%,
respectively, during dry weather conditions (with rainfall less
than 2 mm/d) and 78, 75, and 84% during wet conditions (with
rainfall between 2 and 35 mm/d). Retention of water-diluted
azinphos-methyl introduced via runoff at a level of 0.85 μg/L
was between 77 and 93%.
Chlorpyrifos and endosulfan were measured during runoff in
inlet water at 0.02 and 0.2 μg/L, respectively. However, both
(Schulz, 2004)
Schulz, R. and Peall,
(2001). Effectiveness of
a Constructed Wetland
for
Retention
of
Nonpoint-Source
Pesticide Pollution in
the Lourens River
Catchment,
South
Africa.
Environment
55
Reference
Science
and
Technology, 35, 422426.
(Schulz
2001)
and
Experimental design
Hydrology/climatic conditions/location
Peall,
Results
pesticides were undetectable in the outlet water samples.
Over 5 months, an increased concentration of various
insecticides was detected in the suspended particles at the
wetland inlet: azinphos-methyl, 43 μg/kg; chlorpyrifos, 31
μg/kg; and prothiofos, 6 μg/kg.
No organophosphorus pesticides were found in the outlet
suspended-particle samples, highlighting the retention
capability of the wetland.
A toxicological evaluation employing a Chironomus bioassay
in situ at the wetland inlet and outlet revealed an
89%reduction in toxicity below the wetland during runoff.
- The amounts of atrazine losses in runoff waters varied
during 1994 and 1995 because of rainfall distributions.
- The recommended band application of atrazine minimizes
losses in runoff water over broadcast application.
- Cumulative amounts of metribuzin losses in runoff water
were highest for full broadcast (0.3%-7.4% of the amount
applied)
and lowest for the 60 cm (24-inch) band treatment (0.3%3.4%).
Selim HME, Bengtson
RL, et al. (2000) Runoff
losses of atrazine,
metribuzin,
and
nutrients as affected by
management practices
for
sugarcane.
Louisiana Agricultural
Experiment
Station
Bulletin, 43.
-A focus on the fate of two herbicides;
atrazine and metribuzin, over a three
year growing cycle for sugar cane.
-The second objective was to quantify
fertilizer nutrient losses as well as soil
losses as affected by selected
management practices.
-Study area: South Louisiana.
-Soil type: Commerce silt loam (fine-silty, mixed,
nonacid, thermic, Aeric Fluvaquent).
-Average annual rainfall for study period: 1449mm
Selim HM, Naquin BJ,
et al. (2004) Herbicide
retention and runoff
losses as affected by
sugarcane
mulch
residue.
Louisiana
Agricultural Experiment
Station Bulletin Bulletin
Number 883, 43.
- The purpose of this study was to
evaluate the effectiveness of sugarcane
residue (mulch cover) in reducing nonpoint source contamination of applied
chemicals from sugarcane fields.
- The amounts of extractable atrazine,
metribuzin and pendimethalin from the
mulch residue and the surface soil layer
were quantified during the 1999 and
2000 growing seasons.
- A second objective
was to quantify the retention of atrazine
and metribuzin by the sugarcane mulch
and to characterize their kinetic
behavior in soil.
-Soil type: Commerce silt loam soil (fine-silty, mixed,
superactive, nonacid,
thermic Fluvaquentic Endoaquept).
-Study area: located south of Baton Rouge, Louisiana.
- The mulch residue intercepted significant amounts of applied
herbicides. Extractable concentrations were at least one order
of magnitude higher for the mulch residue compared with that
retained by the soil.
- We found that retention capability of the residue for either
metribuzin or atrazine did not change significantly with the age
of the decaying residue over two growing seasons.
- The presence of mulch residue resulted in consistently lower
rates of disappearance of atrazine and pendimethalin in the
surface soil.
- The presence of mulch residue on the sugarcane rows was
highly beneficial in minimizing runoff losses of the herbicides
applied. A minimum of 50% reduction in runoff effluent
concentrations for atrazine and pendimethalin was realized
when the mulch residue was not removed.
Selim H, Zhou L, et al.
(2003)
Herbicide
retention in soil as
-Evaluation of sugarcane residue
(mulch cover) in reducing herbicide
contaminants from sugarcane fields
-Study site: Baton Rouge, Louisiana, U.S.
-Soil type: Commerce silt loam soil.
-Significant amounts of applied herbicides were intercepted by
the mulch residue
-Concentrations were higher in the mulch residue than the soil.
56
Reference
affected by sugarcane
mulch residue. Journal
of
Environmental
Quality 32, 1445–1454.
Experimental design
through herbicide retention.
-Herbicides: atrazinem metribuzin and
pendimethalin.
Settle S, Goonetilleke A
'Evaluation of wetlands
and wet detention
basins for stormwater
quality improvement.'
-A study looking at nutrient and
suspended solid treatment performance
of constructed wetland/wet detention
facilities.
-An analysis on stream flow and
contaminant concentration
-Study area: Pine Rivers Shire, Brisbane, Australia.
-An urbanizing area.
-There was a variable nature of pollutant discharge and
treatment performance.
-The monitoring of the case study catchments has highlighted
the complex nature of pollutant export processes, the difficulty
in determining accurate information on stream loadings and
the variable nature of waterway and treatment processes.
Seybold, C., Wondi, M.,
Delorem, D. (2001).
Removal
and
degradation of atrazine
and metolachlor by
vegetative filter strips
on clay loam soil.
Communications in Soil
Science and Plant
Analysis, 32(5), 723737.
Simulated filter strips on tilted beds
(2%), clay loam soil
Atrazine, metolachlor
Measured concentrations in runon,
surface runoff, lateral subsurface
movement, leachates & filter strip soils.
Water – 50mm over 25 mins.
Virginia, USA
50mm/hr simulated rainfall over 25 mins.
In total, filter strips removed 53-73% herbicides applied.
Filter strips reduced dissolved atrazine & metolachlor in runoff
(overland flow) by 6% of amount applied. Absence or
presence of switchgrass no effect.
About 56-82% runon volume leached through 30cm soil depth
of filter strips.
In leachate 72-88% was filtered or adsorbed to soil.
Switchgrass reduced runoff volume and increased leachate
volume.
Primary mode of removal in runon was by infiltration & soil
adsorption.
Soil herbicide concentrations greatest near surface, reduced
over 7 weeks. Switchgrass significantly increased degradation
rate of metolachlor, not atrazine.
Infiltration of runoff is key to reduced dissolved herbicides from
moving offsite.
(Seybold et al., 2001)
Sherrard, R.M., Bearr,
J.S.,
Murray-Gulde,
C.L., Rodgers Jr, J.H.
and Shah, Y.T. (2004).
Feasibility
of
constructed wetlands
for
removing
chlorothalonil
and
chlorpyrifos
from
aqueous
mixtures.
Environmental
Pollution, 127, 385-394.
Simulated stormwater runoff treated in
constructed wetland mesocosms.
Insecticides - Chlorpyrifos and
chlorothalonil.
4 experiments, 4 constructed wetlands
(containers) – no pesticides, various
concentrations.
Applied 250L of solution in 2 mins.
Retention time 72 hours.
Hydrology/climatic conditions/location
Results
Observed declines in toxicity to sentinel species - 98 and
100%.
Constructed wetland mesocosms were effective for
decreasing concentrations of chlorpyrifos and chlorothalonil in
simulated stormwater runoff, and decreasing P. promelas and
C. dubia mortality resulting from these exposures.
chlorpyrifos – mostly reduced by 64 hours
chlorothalonil – halved after 12 hours
57
Reference
Shutes, R.B.E. (2001).
Aritificial wetlands and
water
quality
improvement.
Environment
International, 26, 441447.
Experimental design
Considers the role of plants to assist the
treatment of water pollution in manmade wetlands in tropical and
temperate climates.
Highway runoff in urban environment.
Mostly considering heavy metals.
Performance influenced by area, length
to width ratio, water depth, rate of
wastewater loading and retention time.
Removal efficiency – organic material
and SS 80%, nutrients <60%.
-A information pamphlet regarding the
status of riparian and wetland areas on
cane farms in Queensland.
-A promotion of „good farm practice‟
Hydrology/climatic conditions/location
Mai Po Marshes Hong Kong, Putrajaya Lake Malaysia
& a wetland in London.
Smith M, Melvin S, et
al. (1992) 'Vegetative
filter strips for improved
surface water quality.'
Iowa State University:
University Extension.
-An information pamphlet covering
various studies (most covered in the
current literature review) on vegetative
filter strips and their use in filtering
sediments, nutrients and pesticides.
-One study mentioned is in Boone County, Iowa.
Snyder, C.S. (1998).
Vegetative Filter Strips
Reduce Runoff Losses
and Help Protect Water
Quality. News and
Views. Potash and
General overview of vegetative filter
strips.
SS, nutrients and atrazine.
Midsouth USA (Kentucky, Missisippi, Arkansas) annual
rainfall ~52 inches or 135cm.
(Shutes, 2001)
Smith
R
(2008b)
'SmartCane
riparian
and wetland areas on
cane farms: SmartCane
best
management
practice booklet.' BSES
Limited.
Results
Demonstrates that the use of constructed wetlands to treat
wastewater was successful in these locations (no water quality
results presented).
-Covers: drainage discharge into waterways and wetlands and
the benefits of implementing constructed systems.
-Effectiveness of filtration is determined by:
The amount of sediment reaching the VFS (influenced by type
and freq. of tillage in cropland above the VFS, time between
tillage and rain, rain intensity and duration, steepness and
length of slope above VFS).
The amount of time water is retained in the VFS (influenced by
width of filter area and type of vegetation and quality of the
stand)
the infiltration rate of the soil,
Uniformity of water flow through the VFS and,
Maintenance of the VFS.
VFS remove larger sediment particles of sand and silt first,
smaller clay-sized particles settle most slowly.
Because soil-bound nutrients and pesticides are largely bound
to clay particles, VFS may be only partially effective in
removing them.
Presents general overview of the use of vegetative filter strips
for removing sediments, nutrients and pesticides from
agricultural runoff.
Summarises work in Virginia by T.A. Dillaha and others
evaluated the long-term effectiveness of VFS and resulted in
conclusions that VFS are effective for water quality
58
Reference
Phosphate Institute and
the
Potash
and
Phosphate Institute of
Canada. October 1998.
Experimental design
Hydrology/climatic conditions/location
Results
improvement only under certain conditions and maintenance
regimes.
Effectiveness of different tillage systems and widths of VFS.
Most effective – no till, 45ft vegetated filter – reduced runoff
volume, SS, nitrate-N and atrazine.
Research in Arkansas comparing poultry litter and swine
manure applications to fescue showed that total P losses were
reduced with an increase in VFS width to about 30 ft. The
greatest potential for runoff loss usually occurs with the first
storm event after fertilizer or animal manure application. The
runoff loss is dramatically less in subsequent runoff-producing
rains.
Reductions in runoff volume and sediment load with VFS are
paralleled by reductions in pesticide concentrations according
to work in Mississippi with cotton (Table 3) and soybeans
(Table 4). These results indicate that VFS which are effective
in reducing runoff volume and sediment loss are also likely to
be effective in decreasing pesticide and nutrient losses.
59
Reference
Southwick, L., B. Grigg,
et al. (2003). "Atrazine
and metolachlor in
surface runoff under
typical
rainfall
conditions in southern
Louisiana." Journal of
agricultural and food
chemistry 51(18): 53555361.
(Southwick et al. 2003).
Srivastava P, Edwards
D, et al. (1996)
Performance
of
vegetative filter strips
with varying pollutant
source and filter strip
lengths. Transactions of
the
ASAE-American
Society of Agricultural
Engineers 39, 22312240.
Starner K (2009) 'Study
259. Effectiveness of a
constructed treatment
wetland at reducing
pesticide concentration
in agricultural runoff.'
Department of Pesticide
Regulation,
Environmental
Monitoring
branch,
Sacramento.
Stearman GK, George
DB, et al. (2003)
Pesticide removal from
container nursery runoff
in constructed wetland
Experimental design
-Persistence of atrazine and metochlor
in the soil was measured with regard to
runoff concentrations with time after
herbicide application.
-Half lives were calculated for each
herbicide and were measured over 3
years.
Hydrology/climatic conditions/location
-Study site was in the East Baton Rouge Parish,
Louisiana.
-Soil type: Mississippi River alluvial soil (commerce
loam grading silt loam, clay 39.6%
Results
-Atrazine had a soil half life of 10.5-17.3 days and a runoff half
life of 0.6-5.7days.
-Metolachlor had a soil half life of 15.8-28.0 days and a runoff
half life of 0.6-6.4 days.
-This study looked at the effect of
pollution source area length and VFS
length on to VFS removal of nutrients.
-Rainfall applied to the experiment: 50 mm/hr for 1 hr.
-Study site: Fayetteville, Washington County, Arkansas.
-Soil type: Captina silt loam soil (fine-silty, mixed, mesic,
Typic Fragiudult).
-Pollutant concentrations in runoff were unaffected by pollution
source length but demonstrated a first-order exponential
decline with increasing VFS length.
-The purpose of this project is to
determine effectiveness of a
constructed treatment wetland located
in Monterey County at reducing
pesticide concentrations in the surface
water contaminated with agricultural
runoff.
-Herbicides involved in this study:
organophosphate insecticides,
carbamate insecticides, pyrethroid
insecticides and dinitroaniline
herbicides.
-An evaluation of constructed wetlands
sites with and without vegetation
(bulrush Scirpus validus) with regard to
herbicide removal at 3 different loading
rates (flow).
-Study site area: Monterey Bay County, California, U.S.
-Study proposal, no results presented.
-Study site: Baxter, Tennessee, U.S.
-Flow rates: 0.24, 0.12 and 0.06 m3d-1
-At the slower flow rate (greatest hydraulic retention times) a
greater percentage of herbicides were removed.
-Over a 2 yr period the wetlands with plants removed more
(>77%) herbicides than wetland without plants.
60
Reference
cells.
Journal
of
Environmental Quality
32, 1548.
Experimental design
-Herbicides: simazine and metochlor.
Sullivan A Atrazine
management:
Guidelines to achieve
effective weed control
and minimise off farm
movement. In. (Grains
Research
and
Developmental
Corporation
and
Queensland
Government)
Syversen, N. and and
Bechmann, M. (2004).
Vegetative buffer zones
as pesticide filters for
simulated
surface
runoff.
Ecological
Engineering, 22, 175184.
Tingle, C.H., Shaw,
D.R., Boyette, M., and
Murphy, G.P. (1998).
Metolachlor
and
Metribuzin Losses in
Runoff as Affected by
Width of Vegetative
Filter Strips. Weed
Science, 46(4), 475479.
The retention of glyphosate,
fenpropimorph, propiconazole and soil
particles was studied in short-term
buffer zone experiments with simulated
surface runoff. Runoff water containing
pesticides and soil particles was added
directly to the BZ.
The BZ was 5m wide and consisted of
natural grass/herbaceous vegetation.
To calculate retention efficiency of
pesticides and particles through the BZ,
surface runoff was collected before
entering and after passing the BZ.
4 experiments, 5 hours runoff
Tall fescue vegetative filter strips 0.5 to
4.0 m wide were evaluated for their
ability to reduce losses of metolachlor,
metribuzin, and runoff (water and
sediment) in conventionally tilled
soybean.
Hydrology/climatic conditions/location
Results
-Guidelined developed by central Queensland farmers
and staff of the Central Queensland sustainable farming
systems project.
-Recommendations for making atrazine work better:
application timing, rate, volume, method, nozzle selection, use
of tank mixes and adjuvants.
-To reduce runoff from paddocks: use minimum or zero till
farming, opportunity cropping, maintain well grassed
waterways, maintain vegetation buffers in sensitive areas, silt
traps.
-Reduce runoff into water by: banded application, using
alternative herbicides, planting alternative crops, incorporating
atrazine, apply lower rates, precision farming.
Mordre, Norway (70km NW Oslo)
14% slope, silty clay loam
Glyphosphate has high Kd value in Nordic soils,
fungicides also low mobility but particle bound
pesticides detected in watercourses.
The average removal efficiency was 39, 71, 63 and 62% for
glyphosate, fenpropimorph, propiconazole and soil particles,
respectively. Aminomethylphosphonic acid (AMPA), which is a
degradation product of glyphosate, constituted only a small
part of glyphosate (about 10%) in this short-term experiment.
Moderate to high adsorption to soil, however, large proportion
soluble.
Black Belt Branch Experiment Station near Brooksville,
Mississippi 1994-1996.
Runoff plots with flumes, silty clay soils.
Filter strips 4m x 0.5, 1, 2, 3, 4m wide.
Simulated rainfall event (25mm/hr) 2 days after
application of metolachlor and metribuzin.
Total rainfall 744-1411mm/annum – similar trends
observed in each year.
Differences in parameters were significant between filter and
no filter strips regarding filter strip width.
Metribuzin & metolachlor reduced ~50% in 2 days.
Filter strips regardless of width reduced cumulative runoff and
sediment loss at least 46 and 83% respectively.
Herbicide losses, runoff amounts, and sediment amounts, both
within events and cumulative, were regressed in linear,
quadratic, logarithmic, and exponential form against filter strip
width.
Highest surface runoff from unfiltered treatment.
Sediment losses reduced 98-99% with filter strip.
61
Reference
Experimental design
Truong, P., Mason, F.,
Waters, D. and Moody,
P. (???). Application of
Vetiver
Grass
Technology in off-site
pollution
control:
Trapping agrochemicals
and
nutrients
in
agricultural lands.
Sugarcane and cotton.
Sugarcane
Sodic duplex soil, Mackay district.
20x3m plot, 6 treatments, 2
replications.
Atrazine and chlorpyrifos.
Runoff and sediment collected from
ponds lined with strong plastic liners.
Cotton
Emerald Irrigation area.
Hedges located at end of tailwater
drains.
Organochlorine and organophosphate
pesticides, and herbicides diuron,
trifluran, prometryn and fluometuron.
Summarises recent research of ability of
buffers to trap and degrade pesticides in
field runoff.
United
States
Department
of
Agriculture,
2000.
Conservation Buffers to
Reduce
Pesticide
Losses. March 2000.
Hydrology/climatic conditions/location
Results
Cotton in Emerald Irrigation Area.
Sugar – not sure?? – Mackay?
Vetiver Grass Technology (VGT) can be very effective and low
cost way of reducing particle-bound nutrients and
agrochemicals in runoff water from agricultural lands.
Sugar - Agrochemicals could not be analysed in sugarcane
trial. Nutrients – highly effective in trapping particle bound
nutrients such as P and Ca – up to 70% reduction.
Cotton – in first year hedge trapped 86% of total endosulfan in
sediment of runoff water and 67% of chlorpyrifos – compared
with 65% of endosulfan in second year. Highly effective at
trapping sediment bound chemicals.
Herbicides – first year hedges not very effective in trapping
diuron but fluometuron greatly reduced. Second year trapped
48% diuron.
Nutrients – Significant trapping – 73% N, 52% P and 55% S.
United States
Covers types of buffers:
water buffers within fields (grassed waterways),contour buffer
strips, vegetative barriers, Edge of field Field borders, Filter strips, Setbacks, Riparian forest buffer,
constructed wetlands.
Pesticide trapping – good overview of available research.
(USDA, 2000)
Guide to designing buffers for max pesticide trapping
efficiency. Location, width, species selection, economic
considerations.
62
Reference
Experimental design
Hydrology/climatic conditions/location
Results
Impact of buffers on leaching of pesticides and nitrate because buffers increase water infiltration, concern has been
expressed that leaching of pesticides and nitrate might be
increased, possibly to shallow ground water.
Weakly adsorbed pesticides (which would have the greatest
leaching risk) often are not detected at significant
concentrations in runoff, as they quickly move into the soil.
Pesticides detected in runoff are primarily strongly adsorbed
compounds attached to suspended sediment and moderately
adsorbed compounds both adsorbed to sediment and
dissolved in water.
Integrating buffers with BMPs, eg. IPM, pesticide selection,
application timing, banded application, soil incorporation,
conservation tillage, nutrient management, contour planting,
strip cropping, crop rotation, terraces / detention ponds,
irrigation timing, irrigation water management, compaction
reduction, subsurface drainage.
Vellidis G, Lowrance R,
et al. (2002) Herbicide
transport in a restored
riparian forest buffer
system. Transactions of
the ASAE 45, 89-97.
-Effects of a restored riparian forest
buffer system on the transport of
herbicides; atrazine and alachlor.
-250 mm cumulative rainfall after herbicide application
(1 year).
-Study site: Tifton, Georgia, U.S.
-The restored riparian forest buffer had similar effects on
herbicide transport as a mature buffer (effective at removing
herbicides).
Vianello,
M.,
C.
Vischetti, et al. (2005).
"Herbicide losses in
runoff events from a
field with a low slope:
Role of a vegetative
filter
strip."
Chemosphere
61(5):
717-725.
(Wauchope 1978)
-the effect of a narrow vegetative filter
strip was studies on an arable field in
the low lying plains of the Veneto
Region (north-east Italy).
-VFS was made up of trees, shrubs and
grass.
-Herbicides included in study:
metolachlor, terbuthylazine and
isoproturon.
-Study area: Veneto Region (north-east Italy).
-Simulated rainfall: 43mm h-1 and 82mm h-1 intensity.
-Soil type: Fulvi-Calcaric Cambisol. Silty-loam textured,
rich in limestone.
-The herbicide loss with runoff was low but concentrations
were sometimes very high.
-Two VFS effectiveness mechanisms were identified: (i)
dilutions and (ii) a „sponge-like‟ effect, which temporarily
trapped chemicals inside the VFS before releasing them.
- For pesticides with low solubility and high sorption only 1030% of the total loss from the source area occurred with runoff
water (in arora et al 2010)
- for moderately sorbed pesticides w medium solubility, 60100% of total loss from source area was with runoff water (in
arora et al 2010)
63
Reference
Weaver M, Zablotowicz
R, et al. (2004)
Laboratory assessment
of
atrazine
and
fluometuron
degradation in soils
from a constructed
wetland. Chemosphere
57, 853-862.
Experimental design
-A study that looks at the potential of
soils to degrade and sorb atrazine and
fluometuron within a recently
constructed wetland.
-One wetland was disturbed
hydrologically, one was excavated to
provide greater water-holding capacity.
-Conditions were either saturated or
flooded.
Hydrology/climatic conditions/location
-Study site: a constructed wetland near Sunflower
River, Sunflower County, Mississippi, U.S.
-Soil type: Dowling clay (very-fine smectitic, thermic
Typic Endoaqualfs; hydric, clayey alluviam of recent
Holocene age).
Results
-Flooding has a different effect on the sorption and
degradation of the herbicides studies compared to saturated
conditions (longer half life for fluometuron in flooded
conditions).
Webber DF, Mickelson
SK, et al. (2010)
Livestock grazing and
vegetative filter strip
buffer effects on runoff
sediment, nitrate, and
phosphorus
losses.
Journal of soil and
water conservation 65,
34.
-Quantified effects of livestock grazing
management practices and vegetative
filter strip buffers on runoff depth and
loss of TSS and nutrients (N and P)
under natural hydrologic conditions.
-Three types of vegetative buffer:
paddock area and vegetative area (with
varying ratios) and no buffer (control).
-Three grazing management practices:
continuous, rotational and no grazing
(control).
-Study site: Central Iowa, U.S.
-Results from 2001 and 2002 suggest no difference in
vegetation ratio buffers for losses of runoff, TSS and nutrients.
-The 2003 season results indicate more effective removal of
runoff and TSS from livestock grazing sites with the higher
ratio of vegetation to pasture buffer.
WetlandCare Australia
The
Russell
and
Mulgrave catchments.
In
'Queensland
Wetlands Programme'.
(Ed.
MLaTN
WetlandCare Australia).
-A pilot program to „scope‟ out wetlands
in the Great Barrier Reef catchment.
The primary focus for this publication
was the Russell and Mulgrave
catchments. These were demonstration
improvement projects on privately
owned cane growing land in the Russell
catchment.
-Works included: construction of a
sediment trap, riparian and aquatic
weed spraying and revegetation, control
of invasive plants and revegetation work
resulting in the completion of a habitat
corridor loop adjoining the Eubenangee
Swamp.
-Looks at 5 models for modeling
pesticide reduction by VFS buffers. A
comparison of the models is made
based on a criteria matrix.
-Part of the Great Barrier Reef catchment. Connected to
Russell River.
-Wetland rehabilitation is a difficult challenge in the wet tropics
especially during a prolonged wet season. Short timeframes
can‟t cater for unforeseen events.
-Spot spraying to remove an invasive plant species proved to
be a long-term, cheap and time-flexible strategy even in nearly
inaccessible creek banks and had great potential in the wet
tropics.
-Specialized equipment was created including: a purpose built
spray boom to allow more efficient spraying of herbicide on
steep banks.
Winchell, M. and T.
Estes (2009). A review
of simulation models for
evaluating
the
-Conceptual and functional differences of each model is
explained. The relevant differences are below:
• Model Temporal Scale: VFSMOD-W is a storm event based
model. The other models are continuous models.
64
Reference
effectiveness of buffers
in reducing pesticide
exposure. Montpelier,
Stone Environmental
Inc. 1: 1-51.
Experimental design
Wong THF, Breen PF,
et al. (1999) Ponds vs
wetlands - Performance
considerations
in
stormwater
quality
management.
In
'Conference
on
Comprehensive
Stormwater and Aquatic
Ecosystem
Management'.
Auckland, New Zealand
pp. 22–26
-A discussion on the various issues and
performance considerations associated
with the comparison of ponds and
wetlands for storm-water pollution
control.
Yuan, Y., Bingner, R.L.
and Locke, M.A. (2009).
A Review of the
effectiveness
of
vegetative buffers on
sediment trapping in
agricultural
areas.
Ecohydrology, 2, 321336.
Aims to develop an understanding of
riparian buffer processes towards water
quality modelling/monitoring and
nonpoint source pollution assessment –
particularly sediment reduction.
Hydrology/climatic conditions/location
United States
Results
• Storm Duration: APEX, REMM, and VFSMOD-W use a subdaily time step infiltration model. PRZM-BUFF and SWAT use
a daily time step infiltration model. A sub-daily infiltration
model may have advantages in capturing the dynamics of
short-duration, high intensity rainfall events which are
significant runoff and sediment load producers.
-The strengths and weaknesses of each model is explained
-Ponds generally provide a higher level of storm-water
detention compared to wetlands and therefore are expected to
be more effective in promoting sedimentation as a mechanism
for storm-water pollution interception.
-Extensive pooling also has limitations due to lack of
vegetation due to depth of the water and conditions that
promote remobilization of contaminants in the sediment.
-Constructed wetlands can be designed to promote certain
characteristics and minimize others by containing ponds and
wetland characteristics.
Although sediment trapping capacities are site- and
vegetation-specific, and many factors influence the sediment
trapping efficiency, the width of a buffer is important in filtering
agricultural runoff and wider buffers tended to trap more
sediment.
Sediment trapping efficiency is also affected by slope, but the
overall relationship is not consistent among studies.
Overall, sediment trapping efficiency did not vary by
vegetation type and grass buffers and forest buffers have
roughly the same sediment trapping efficiency.
Summary table in Appendix shows various studies, trapping
efficiencies and rainfall (all less than 70mm).
Results indicated that under conditions of relatively shallow
flow not concentrated in channels, gently sloping, densely
vegetated 3 m buffers are likely to limit transport of sediment
from uplands to streams (Robinson et al., 1996; Lee et al.,
1999; Rankins et al., 2001; Blanco-Canqui et al., 2004a,b),
whereas moderately steep, less densely vegetated buffers of 3
m may be vulnerable to much higher rates of sediment
delivery (Daniels and Gilliam, 1996).
65
Reference
Experimental design
Hydrology/climatic conditions/location
Results
Buffers greater than 6 m are effective and reliable in removing
sediment from any situation; for example, Hook et al. (2003)
reported that more than 97% of sediment was trapped in the
rangeland riparian buffer area with a 6 m buffer in any of the
experimental conditions they studied.
66
67