177
Measurement techniques and yield estimates of fodder beet in
Canterbury and Southland
H.G. JUDSON1, S. McKENZIE1, S. ROBINSON1, A. NICHOLLS2 and A.J.E. MOORHEAD1
1 Agricom, P.O Box 3761, Christchurch, New Zealand
2 Macfarlane Rural Business Ltd, Ashburton, New Zealand
[email protected]
Abstract
A survey of commercial fodder beet crops across
Canterbury and Southland was undertaken to determine
average yields and to provide some basic information
on commercial crops. Commercial yields were
approximately 19 t DM/ha but higher yields (34 t
DM/ha) were achievable. Dry matter content (DM%)
of bulbs was higher for lighter than for heavier bulbs.
Variation in DM% between bulbs was greater than
the variation between parts (inner and outer fractions)
of the bulb suggesting a rapid method of sampling
multiple bulbs may lead to increases in accuracy of
DM% assessment. A rapid coring method was tested.
on the commercial yields (both dryland and irrigated)
being achieved in Canterbury and Southland.
Methods
Survey
Yields of commercial fodder beet crops in Canterbury
and Southland were collected between 2011 and
2016. This included yields from the “Fodder Beet
Profit Partnership” group (A. Nicholls unpubl. data)
over 3 years (2014-2016) and on-farm survey data by
Agricom. Fodder beet yield (t DM/ha) in each paddock
(n=132) was assessed using a procedure similar to those
described by Dairy NZ, Chakwizira et al. (2014) and A.
Nicholls (pers. comm., for the Fodder Beet Partnership
Group), as outlined briefly below.
Keywords: fodder beet, yield, survey, dry matter yield
Row spacing was determined for each paddock by
random selection of a start row (row 1) and measuring
Introduction
the distance between the middle of the plants in this row
Fodder beet (Beta vulgaris) has become a popular forage
across 10 inter-row spaces to row 11. The distance (in
for feeding sheep, cattle and deer typically through the
metres) was divided by 10 to determine row spacing.
autumn and winter months in southern New Zealand.
At least five randomly selected sites within
This increased interest in fodder beet is a recognition
representative parts of each paddock were sampled. At
of the crops high yield and utilisation potential and feed
each site, all beets were removed from a section of a
quality relative to other options (Westwood & Mulcock
single row, the length of which provided a 2 m2 sample
2012; Chakwizira et al. 2013). The practical use of
based on the row spacing (e.g., 4 m in length for a 50 cm
fodder beet grazed in situ for both beef and dairy cows
row spacing or 4.44 m when row spacing was 45 cm).
is unique to New Zealand in its scale and has benefited
Any soil aggregating around the bulb was removed by
from recent research (Gibbs 2011; Gibbs & Saldias
scraping with a blade and then the tops were removed
2014).
by cutting as close to the crown of the bulb as possible.
The estimation of crop yield is an important aspect
The fresh weight of bulb and leaf was determined using
of fodder beet usage. Accurate yield estimation is
portable scales with a resolution of 0.01 kg.
important for feed budgeting purposes, to allow
A sample of bulbs (n=3-5) and a subsample of leaf
appropriate allocations to livestock through full
(approximately 300 g) were selected from each site for
transition, to allow comparison of feed costs, selling
DM% determination. Leaf samples were oven-dried at
crops in situ and benchmarking agronomic outcomes.
65°C for 48 hrs to determine DM%. Bulbs were cut into
Anecdotal evidence suggests large variations in crop
quarters lengthways and then one quarter was diced and
yields across the industry but industry statistics are not
shredded in a kitchen blender. Shredded samples were
yet available.
then weighed into pre-weighed trays and oven-dried at
Estimates of fodder beet yield relies on the
65°C in a thin layer until constant weight was achieved
determination of fresh weight per unit area and
at around 48 hrs.
DM% of both bulb and leaf. This paper describes the
Paddock yield (t DM/ha) was calculated as the
development of techniques to determine dry matter
average of site measurements:
percentage and to provide some broad industry statistics
(total fresh wt leaf (kg) x leaf DM%) +(total fresh wt bulb (kg) x bulb DM%)
Site Yield (t DM/ha) =
x10
2
[
ISSN 2463-2872 (Print) ISSN 2463-2880 (Online)
]
178
dates, soil
types, moisture profiles and soil fertility was 19 ± 0.5 t DM/ha (mean ± SEM) and
Results
varied from 8-34 t DM/ha (Figure 1).
The average commercial fodder beet crop yield in early winter for a range of cultivars, sowi
Journal
New Zealand
78: (2016)
dates, soil
types,ofmoisture
profilesGrasslands
and soil fertility
was177-180
19 ± 0.5 t DM/ha
(mean ± SEM) an
varied from 8-34 t DM/ha (Figure 1).
Dry matter sampling method
DM% of both bulb and leaf was determined (using
the method above) for a range of cultivars in field
experiments.
The variation in DM% throughout the bulb was
determined by separating bulbs (n=18) (from a range
of low and medium DM% cultivars) into top, middle
and bottom fractions and further into inner and outer
fractions (see Figure 6). Each fraction was shredded
and dried at 65°C for 48 hrs to determine DM%.
The use of a coring device was also evaluated for
sampling bulbs. A corer (1 cm in diameter) wasFigure
used1 Frequency distribution of fodder beet dry matter yield from 132 commercial crops
surveyed
and Southland, New Zealand.
to sample bulbs (n=56), from a range of cultivars,
at in Canterbury
Figure 1 Frequency distribution of fodder beet dry matter
1
Frequency
distribution
of 132
fodder
beet dryaround
matter
yield
from 132
the top of the bulb and on one side, extractingOna average,
12-Figure
leaf made up 17%
of this
yield
representing
3.5
t DM/ha,
butcommercial
varied fromcrops
yield
from
commercial
crops
surveyed
in
and Southland, New Zealand.
5-40%.surveyed in CanterburyCanterbury
15 cm long sample. The other side was quartered
and Southland, New Zealand.
On average, leaf made up 17% of this yield representing around 3.5 t DM/ha, but varied fro
longitudinally and its DM% determined.
5-40%.
Linear regression was used to describe the
relationship between bulb weight, bulb DM% and DM
yield. A Duncan test was performed on bulb fractions
to determine significant differences (P>0.05) in DM%.
Results
The average commercial fodder beet crop yield in early
winter for a range of cultivars, sowing dates, soil types,
moisture profiles and soil fertility was 19 ± 0.5 t DM/ha
(mean ± SEM) and varied from 8-34 t DM/ha (Figure
1).
On average, leaf made up 17% of this yield
representing around 3.5 t DM/ha, but variedFigure
from2 Dry matter content of fodder beet bulbs (n=1592) (variable fresh weights) from a
Figure 2 Dry matter content of fodder beet bulbs (n=1592)
5-40%.
range of crop cultivars surveyed in Canterbury and Southland, New Zealand.
(variable fresh weights) from a range of crop
Figure 2 Dry matter content of fodder beet bulbs (n=1592) (variable fresh weights) from a
The DM% of fodder beet bulbs for different
crop
cultivars
surveyed
Canterbury
Southland,
The DM%
ofoffodder
beet bulbs
for different
crop in
cultivars
rangedand
from
8-28%
and were
range
crop cultivars
surveyed
in Canterbury
and Southland,
New
Zealand.
cultivars ranged from 8-28% and were negatively
New
Zealand.
negatively correlated with bulb
size,
in that heavier bulbs had a lower DM% (Figure 2). This
correlated with bulb size, in that heavier bulbs had The
a DM% of fodder beet bulbs for different crop cultivars ranged from 8-28% and were
negatively correlated with bulb size, in that heavier bulbs had a lower DM% (Figure 2). Thi
equivalent inner fraction (18.3%) but the top (19.0%)
lower DM% (Figure 2). This represents approximately
no different to the bottom (19.2%) or mid-section
a 1 unit decrease in DM% for every 1 kilogram of
(19.0%).
additional fresh weight. Cultivars broadly conformed
The coring method returned similar bulb dry
to groups based on DM %.
matter contents to the more conventional longitudinal
Figure 3 provides individual bulb dry matter content
quartering method, regardless of DM% (Figure 7).
measurements for cultivars classified as having
medium (cv. Rivage) or low (cv. Brigadier) dry matter
Discussion
contents. While these two cultivars represent two
The survey described here estimated average fodder
distinct populations, there was considerable variation
beet yields across Canterbury and Southland to be
between bulbs of the same fresh weight and cultivar,
approximately 19 t DM/ha. This is similar to estimates
and individual cases can overlap these broad grouping.
of 15-18 t DM/ha recorded in cultivar trials in southern
Survey data were analysed to determine if the average
New Zealand (Milne et al. 2014) but lower than the
DM% of the bulb was correlated with final yield of the
potential of this crop in some areas which are reported
crop. For a range of cultivars and crops yields (n=76),
to have reached 40 t DM/ha (Milne et al. 2014). The
there was no relationship between the DM% of bulb
highest yielding fodder beet crops in this survey reached
and final crop yield (Figure 4).
34 t DM/ha confirming that these yields are possible
The DM content of leaf averaged 11.4% (range
(Figure 1). Agronomic factors such as sowing date, field
7-18%) for 68 leaf samples across cultivars (Figure 5).
emergence, plant population, weed, insect and disease
There was significant (P<0.05) variation in the DM%
control, fertiliser applications and optimal irrigation
of different fractions of the fodder beet bulb (Figure
are likely to affect yield alongside environmental
6). The outer fraction (19.8%, average of top, mid and
conditions such as thermal time accumulation (◦C day)
bottom outer portions) was higher in DM% than the
bulbWhile
(Figure
6).two
The outer fraction (19.8%, average of top, mid and bottom outer portio
having medium (cv. Rivage) or low (cv. Brigadier) dry matter contents.
these
Figure
3 provides
bulb
dry matterthere
content
for cultivars
classified
as
cultivars
representindividual
two distinct
populations,
wasmeasurements
considerable higher
variation
bulbs the
of equivalent inner fraction (18.3%) but the top (19.0%) no differ
inbetween
DM% than
having
medium
(cv.
Rivage)
or
low
(cv.
Brigadier)
dry
matter
contents.
While
these
two
the same fresh
weight
and
cultivar,
and
individual
cases
can
overlap
these
broad
grouping.
the
bottom
(19.2%)
or
mid-section
Measurement
techniques
and yield
(H.G.variation
Judson,between
S. McKenzie,
S. Robinson,(19.0%).
A. Nicholls and A.J.E. Moorhead)
179
cultivars represent
two distinct
populations,
thereestimates...
was considerable
bulbs of
the same fresh weight and cultivar, and individual cases can overlap these broad grouping.
Inner
Outer
20.0%
18.0%
19.6%
18.3%
19.8% 18.6%
Top
Mid
Bottom
Figure 3 Bulb dry matter percentage of a low (n= 92) (■) and a medium (n=132) (○) dry
The coring method returned similar bulb dry matter contents to the more conventional
matter content cultivar of various fresh weight.
longitudinal
quartering method, regardless of DM%.
Figure 3 Bulb
dry3matter
percentage
of a percentage
low (n= 92) (■)
medium
(n=132)
Figure
Bulb
dry matter
of aand
lowa(n=
92) (n)
and (○) dry
Survey data were analysed to determine if the average DM% of the bulb was correlated with
matter content cultivar ofavarious
fresh
weight.(¡) dry matter content cultivar
medium
(n=132)
Figure
6 Dry matter percentages as measured for different
final yield of the crop. For a range of cultivars and crops yields (n=76), there was no
various
fresh
parts of the fodder beet bulb (mean of 18 bulbs).
relationship
between
the of
DM%
of bulb
and
final
crop yield
(Figure
Survey
data were
analysed
to
determine
if weight.
the
average
DM%
of the4).
bulb was correlated with
final yield of the crop. For a range of cultivars and crops yields (n=76),
there
Figure
6 was
Dryno
matter percentages as measured for different parts of the fodder beet bulb
relationship between the DM% of bulb and final crop yield (Figureof
4).18 bulbs).
Figure 4 Figure
The relationship
between
fodder beet
bulb DM%
andbeet
total bulb
fodderDM%
beet crop yield (t
4 The
relationship
between
fodder
DM/ha) for 76 crops. and total fodder beet crop yield (t DM/ha) forFigure
7 between
Relationship
between
matter of
content
Relationship
dry matter
contentdry
estimates
fodderestimates
beet bulbs using
76 7 Figure
The DM content of leaf averaged 11.4% (range 7-18%) for 68 leaf samples across
cultivars.
quartering
orofa fodder
coring technique.
beet bulbs using longitudinal quartering
Figure 4 The relationshipcrops.
between fodder beet bulb DM% and total fodder longitudinal
beet crop yield
(t
or a coring technique.
DM/ha) for 76 crops.
Discussion
The survey described here estimated average fodder beet yields across Canterbury and
Southlandbeet
to be crops
approximately
19 t DM/ha.variable
This is similar
of 15-18 t DM/ha
are inherently
due totoestimates
the inevitable
recorded in cultivar trials in southern New Zealand (Milne et al. 2014) but lower than the
gaps
in rows
left
bywhich
plants
that failed
establish.
In (Milne
potential of
this crop
in some
areas
are reported
to havetoreached
40 t DM/ha
al. 2014).many
The highest
yielding
fodder
beet crops
this survey
reached 34 have
t DM/ha confirm
cases,
where
only
3-5 in
sites
in paddocks
that these yields are possible (Figure 1). Agronomic factors such as sowing date, field
been sampled to generate the paddocks mean, 95%
emergence, plant population, weed, insect and disease control, fertiliser applications and
confidence
intervals
typically
than conditions
± 2 t DM/
optimal irrigation
are likely
to affectare
yield
alongside greater
environmental
such as ther
time accumulation
(◦C day)
and soil
Improvements in agronomy on-farm are likely to
ha and more
likely
± type.
4 t DM/ha.
increase average yields, however, in many cases yields are constrained by growing crops o
Leaf measured in early winter contributed 17% of
free-draining soils of low organic matter in dry and or drought affected sites. This suggests
the totalmay
DM
which
on average
equated
paddock selection
be ayield
key factor
in determining
yield
potentialto
andaround
maybe responsibl
the wide range
yields reported
here. Other represents
crops such as akale
yielded only
11 t DM/ha
3.5 tofDM/ha.
This probably
mid-way
point
across similar areas (Judson & Edwards 2008).
Figure 5 Frequency distribution of DM% for fodder beet leaf.
between greater autumn leaf yields and potentially
Figure 5 Frequency distribution of DM% for fodder beet leaf.
Although lower
this survey
returned
an estimated
t DM/ha as
for fodder
beet crops, it is
yields
towards
the mean
end ofof19winter
leaf drop
important to give context around confidence in this estimate. Fodder beet crops are inheren
There was and
significant
(P<0.05)
variation in the DM%
of different on-farm
fractions ofvariable
the fodder
beet
soil type.
Improvements
in agronomy
are
occurs.
However,
survey
did highlight
leafIn many ca
due
to the inevitable
gaps the
in rows
left by plants
that failed to that
establish.
bulb (Figure 6). The outer fraction (19.8%, average of top, mid and bottom outer
portions)
where
only
3-5was
sites
in
paddocks
have
beentotal
sampled
toin
generate
the
paddocks
mean, 95%
likely
to
increase
average
yields,
however,
in
many
made
up
much
less
of
the
DM
some
crops
which
higher in DM% than the equivalent inner fraction (18.3%) but the top (19.0%)
no different
to
confidence
intervals
areissue
typically
greater
than ± 2relied
t DM/ha
and
more
likely ± 4 t DM/ha.
cases
yields
were
constrained
by
growing
crops
on
may
be
an
if
leaf
is
being
on
as
an
important
the bottom (19.2%) or mid-section (19.0%).
in early
winter contributed
17%considerable
of the total DM yield
which onin
average equ
free-draining soils of low organic matter in dry andLeaf
or measured
protein
source.
There was
variation
to around 3.5 t DM/ha. This probably represents a mid-way point between greater autumn l
drought affected sites. This suggests paddock selection
the
dry
matter
percentage
of
leaf
(7-18%),
averaging
yields and potentially lower yields towards the end of winter as leaf drops occurs. However
Inner
Outer
may be a key factor in determining yield potential and
20.0% for 18.0%
maybe responsible
the wideTop
range of yields reported
here. Other crops such as kale yielded only 11 t DM/ha
across similar areas (Judson & Edwards 2008).
18.3%
Mid an estimated mean
Although this19.6%
survey
returned
of 19 t DM/ha for fodder beet crops, it is important to
give context around confidence in this estimate. Fodder
19.8% 18.6%
Bottom
11.4% DM. Using the same fresh weight this range in
DM% would have seen leaf yields vary from 2.1 to 5.5,
which is not large in the context of the total yield, but
again may be important if leaf is being considered an
important source of protein.
Bulb dry matter percent varied widely (8-28%) and
was negatively correlated with bulb size. Regardless
180
Journal of New Zealand Grasslands 78: 177-180 (2016)
of variety, increasing bulb size was found to reduce
DM% by 1 percentage unit for every extra kilogram in
bulb fresh weight. This has important implications for
measuring DM% to calculate DM yields. Selecting a
sample of bulbs that do not represent the average bulb
size of the paddock will lead to over or underestimating
of the DM% and therefore the yield. There was also
a considerable range (8-10 percentage units) in the
DM% of bulbs within a cultivar for similar sized bulbs.
This possibly reflects environmental effects such as
soil moisture, fertility and crop age, and highlights
the danger of using “average values” to determine the
DM% of a crop.
There was no relationship between average bulb
DM% and total yield. This contrasts with the finding
of Milne et al. (2014) who reported a strong correlation
between these variables for seven cultivars in field
experiments across Canterbury and Southland. A lack
of an effect of DM% on yield in this survey suggests
that in commercial crops total DM yield may be more
sensitive to factors other than DM%, such as soil
moisture profiles and fertility.
The different parts of the fodder beet bulb returned
different DM contents, with outer segments being
higher than inner segments. This supports the advice
to submit longitudinal sections of both inner and outer
bulb for DM% assessment to capture this variation.
However, given the variation in DM% between bulbs
(Figure 3), even within a paddock of the same cultivar,
was much larger (8-10%) than within a bulb (1-2%),
increasing the number of bulbs sampled will lead to
a better estimate of bulb DM%. The coring device
provided a rapid, in-paddock method of sampling
numerous bulbs.
ACKNOWLEDGEMENTS
Summary
This survey has provided some understanding of both
yield and DM% of fodder beet crops across parts of
Canterbury and Southland. This information provides
growers and researchers with commercial benchmarks
for other comparisons. It has highlighted the danger
of using a single bulb for DM% measurement and the
need to test leaf material for DM%. It also provides
some validation of a coring technique for sampling
bulbs for DM%.
The authors acknowledge Beef + Lamb New Zealand
for funding the ‘Fodder Beet Profit Partnership’ which
has contributed data for this paper, and the considerable
efforts of the Kimihia Research Team carrying out crop
yield assessments and processing fodder beet bulbs.
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