Field Evaluations of Liquid Organic
Fertilizers on Strawberries
Mark
k Gaskell
k ll
Farm Advisor – Santa Maria
University of
California
Cooperative
Extension
Overview – in-season organic
g
ffertilization
•
Need efficient fertilization practices
- materials uncertain, changing
- lack solubility
•
Need mineralization for plant uptake
- biological process
•
Commercial organic N fertilizers
- dry bulk, + pelleted
- liquid
University of California Cooperative Extension
Santa Maria, CA
Concentrate on Nitrogen
g
• Nitrogen is often most critical limiting factor
• Nitrogen status is shifting
• Phosphorus,
Phosphorus potassium less problematic
- composts, powdered, granular, liquid, etc
- tend to accumulate in soils
- can apply preplant incorporated – use
economical materials, manage long term
• Preplant N gone after 6-8 weeks
University of California Cooperative Extension
Santa Maria, CA
N availability from organic fertilizers related to
characteristics that affect mineralization
•
Portion
P
i
off material
i l iis ammonium,
i
amino
i
acid
id ffragments rapidly transformed to ammonium
- relatively rapid mineralization and N availability
- temperature??
•
•
Chilean nitrate is special case
Particulates collect in system even when finely ground
and pre- sieved
- growers bypass filtration
- losses of material?
- losses in irrigation distribution uniformity
•
Hidden losses likely throughout the system
University of California Cooperative Extension
Santa Maria, CA
Rate o
of N Minerralization aand Nitroggen Uptakke
Pre‐plant organic
p
g
material
mineralization
Crop N demand
0
....
2 4 4
6
6 10
10 8
8 Week
Time
1
2 14
14 16
16 18
18 20
Rate o
of N Minerralization aand Nitroggen Uptakke
Pre‐plant organic
p
g
material
mineralization
Strawberry
Crop N demand
SSouthern h
Districts
Northern Northern
DIstricts
....
0
2 4 6
6 10
10 8
8 Week
1
2 14
14 16
16 18
18 20
Will need periodic (weekly(?) Will
need periodic (weekly(?)
organic N injection
Time
- not 100% efficient
- leaching losses and EC mgmt
Accumu
ulation off N (lb/ A))
Seasonal Nitrogen Accumulation for Celery
Compare to corn?
20-25 ppm nitrate-N?
Days After Transplanting
MG2
Match N availability
y to crop
p needOrganic strawberries
• Transplanted strawberry N uptake about 4 lb N/acre
- first 90 days.
• During the next 20 weeks of growth, N uptake
approaches 70 to 90 percent of seasonal total
~ 130-150 lb N/acre
/
• N uptake is steady and continuous for the entire period
• Current
C
t strawberry
t
b
ffertigation
ti ti
reccs ffor FL
= 0.3 lb – 0.75 lb N /acre/day
University of California Cooperative Extension
Santa Maria, CA
Slide 10
MG2
chek stby numbers
Mark Gaskell, 12/25/2008
Weekly residual soil nitrate-N at varying
weekly organic N fertigation rates
2008 Season – Santa Maria
Residual Soill Nitrate- N ((ppm) /
R
Total Vegetaative N (lbs/A
/Acre)
Total Strawberry Vegetative N & Residual Soil Nitrate- N
at Different Weekly Organic N Fertilization Rates
Manzanita Ranch -Santa Maria, 2008
Accumulation of strawberry plant fresh weight at varying rates
of weekly organic N fertigation
Accumulation of strawberry plant dry weight at varying rates
of weekly organic N fertigation
Weekly strawberry production from plots receiving varying
rates of weekly organic N fertigation
Santa Maria, CA – 2008 Season
Total Frruit Yield (ggram/plot)
2000
1500
1000
500
0
12 lb N
6 lb N
3 lb N
Organic strawberry total fruit yield in plots receiving varying
rates of organic N fertigation
Santa Maria, CA – 2008 Season
To
otal comm
mercial yiield (lbs/A
Acre)
38000
36000
34000
32000
30000
28000
26000
24000
22000
20000
3
6
Weekly N Fertigation (lbs N /acre)
12
Organic strawberry total fruit yield in plots receiving varying
rates of organic N fertigation
Santa Maria, CA – 2008 Season
To
otal comm
mercial yiield (lbs/A
Acre)
38000
36000
34000
32000
30000
Weekly N
(lb)
Applied Season
Total (lb)
Cost / Unit
($/ lb N)
Season Cost
($/A)
28000
3
90
6
540
26000
6
180
6
1080
24000
12
360
6
2160
18
540
6
3240
22000
20000
3
6
Weekly N Fertigation (lbs N /acre)
12
Weekly average strawberry fruit weight from plots receiving
varying rates of weekly organic N fertigation
Santa Maria
Maria, CA – 2008 Season
25
Average F
Fruit Weightt (g)
20
15
10
12 lb N
5
6 lb N
3 lb N
0
26-Mar
26-Apr
26-May
26-Jun
26-Jul
Soil residual nitrate-N following application of varying rates of organic N fertigation
Santa Maria, CA - 2009 Season
16
12
10
8
6
18 lbs/A/wk
4
12 lbs/A/wk
2
6 lbs/A/wk
Date
9-F
Feb-05
2-F
Feb-05
26-JJan-05
19-JJan-05
12-JJan-05
5-JJan-05
29-D
Dec-04
22-D
Dec-04
15-D
Dec-04
8-D
Dec-04
1-D
Dec-04
0
24-N
Nov-04
Ressidual soil nittrate N (ppm
m)
14
Weekly residual soil nitrate- N at varying
weekly organic N fertigation rates
Santa Maria,
Maria CA – 2009 Season
16
Agrolizer
Soil Resid
S
dual Nitrate
e N (ppm)
14
12
10
0
8
6
4
2
18 lbs/A/wk
12 lbs/A/wk
6 lbs/A/wk
0
1/5/09
1/13/09
1/20/09
1/27/09
Sample Date
2/3/09
2/10/09
Weekly residual soil nitrate N following application of varying rates
of weekly organic N fertigation
12
Residual S
R
Soil Nitrate
e N (ppm)
Nitriboost
10
8
6
4
18 lbs/A/wk
2
12 lbs/A/wk
6 lbs/A/wk
0
Sample Date
Soil Nitrate – N Sampling?
Summary
In-season organic strawberry
b
ffertilization
l
• No apparent effect
ff
off preplant
l
compost.
• Challenge is to match N availability with crop demand.
• Diverse liquid organic fertilizers but little known about most
efficient materials, rates, timing of applications.
• Strawberries have little appreciable N uptake until.
mid –February (12 weeks post transplant) in Santa Maria.
• Plant growth and yield directly related to weekly applied N
in the range of 3,
3 6
6, 12 lb N per acre week
week.
• Current trials confirming soil and plant parameters with
expanded range of materials and fertigation rates.
University of California Cooperative Extension
Santa Maria, CA
Field Evaluations of Liquid Organic
Fertilizers on Strawberries
Mark
k Gaskell
k ll
Farm Advisor – Santa Maria
University of
California
Cooperative
Extension
Weekly residual soil nitrate-N at varying in-season
N fertilization rates (CAN 17)
nitrate-N (p
Resiidual soil n
ppm)
180
160
10 lb N
140
5 lb N
120
2.5 lb N
100
Begin Fertigation
80
60
40
20
0
Sampling Date
Rainy period
Weekly Residual Soil Nitrate-N at Varying Weekly
N Fertigation Rates (CAN 17)-
25
0 Pre-plant
Residu
ual Soil Nittrate N (pp
pm)
10 lb N
20
5 lb N
2.5 lb N
15
10
5
0
Date