Harvest Report Year 2 (2014 season) on Trial at Coomandook.
Rebecca Tonkin
Rural Solutions SA
08 8539 2125 0427 273 891 [email protected]
Only the one trial was monitored this year, the large trial comparing spading, ploughing and various OM/Fertiliser
treatments.
Spading/Ploughing Trial with Organic Matter
The aim of the main trial was to overcome water repellence on the sand, and improve the nutrition of the soil at
depth. The treatment were those that were applied in 2013, and the site was sown to lupins on the 24/5 May 2014,
and treated as per district practice.
Soil treatments from 2013 were Control (nil), Mouldboard ploughing (MB) and Spading.
Nutrition treatments from 2013 were Aged Pig Manure (APM), Composted Pig Manure (CPM) at 10 t/ha, cereal
straw, triticale silage and vetch hay at 5 t/ha, composted grape marc (TPR) at 20 t/ha, and DAP fertiliser, applied
before sowing and then at 3 week intervals afterwards giving a total of ~ 40 units of N and P (Fert 2) , 20 units (Fert
1) and 10 units (Fert 3).
No new nutrition treatments or soil treatments were applied in 2014, the monitoring was to look at the ongoing
effects of the 2013 treatments.
The trial was replicated 4 times, so all treatments were done 4 times spread out over the trial area.
The harvest results are shown in the table and graph below, firstly as the actual amounts, then as a % of the control
(no soil treatment, no extra nutrition, only the usual farmer care).
Actual Yield (t/ha)
Soil_Mod
APM
Cereal
Control
CPM
Fert 1
Fert 2
Fert 3
Silage
TPR
Vetch
Control
1.34
1.35
1.41
1.38
1.17
1.28
1.25
1.05
1.22
0.83
MB
1.84
1.84
1.65
1.83
1.67
1.66
1.85
1.75
1.56
1.67
Spader
1.91
2.04
1.57
2.26
1.86
2.14
1.34
1.67
1.73
1.42
APM
Cereal
Control
% of control
Soil_Mod
Control
CPM
Fert 1
Fert 2
Fert 3
Silage
TPR
Vetch
95%
96%
100%
98%
83%
91%
89%
74%
87%
59%
MB
130%
130%
117%
130%
118%
118%
131%
124%
111%
118%
Spader
135%
145%
111%
160%
132%
152%
95%
118%
123%
101%
The control–unmodified soil has a yield of 1.41 t/ha, and the nutrition treatments on the unmodified soil are similar
or lower yielding. Vetch and silage were particularly low – it may be that the remaining organic matter affected the
lupins in a negative way. There may have been higher root disease, or the concentration of nutrition in the topsoil
may have reduced root growth into the subsoil, leading to haying off in the dry spring.
Mouldboard ploughing on average increased the lupin yield. Note that the cereal straw treatments on both the MB
plough and the spader showed yield improvements in 2014, as opposed to severe yield penalty in 2013. Nutrition
that was tied up in 2013 may have become available to the lupins in 2014.
Spading increased yield again over the MB plough results. When the nutrition treatments are averaged out, it can
clearly be seen that both MB plough and spader have improved yields over the control.
Yield t/ha
Soil Mod Trial Coomandook 2014
Soil Mod effects
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Control
MB
Spader
When nutrition is added into the results, spading shows a slight advantage over MB ploughing for most of the
nutrition treatments
Simmons Soil Mod Trial Coomandook 2014
Lupins Yield (t/ha)
2.75
2.5
2.25
2
Yield t/ha
1.75
Control
1.5
MB
1.25
Spader
1
0.75
0.5
0.25
0
APM
Cereal Control
CPM
Fert 1
Fert 2
Fert 3
Silage
TPR
Vetch
A reduction in yield is seen in most of the nutrition treatments on the control plots. This may be due to the early dry
spring, as plants with high early vigour but with shallow root depth would have suffered more moisture stress than
those with deeper root systems in the modified soils.
Simmons Soil Mod Trial Coomandook 2014
Lupins % of control
180%
160%
140%
120%
Control
100%
MB
80%
Spader
60%
40%
20%
0%
APM
Cereal Control
CPM
Fert 1
Fert 2
Fert 3
Silage
TPR
Vetch
Profit/Loss Analysis
An analysis of the $ benefits of the treatment was done, assuming a lupin price of $400 per ton (from Paul
Simmons).
In year 2, there are no costs of treatments, so in year 2 alone, the increase or decrease in the lupin yield is what
determines whether there was additional profit or loss. Additional profit was made in the MB plough and spaded
plots, ranging from $50-$320 per ha. The reduction in production on the nutrition treated control plots, combined
with the higher lupin price means that a loss in production causes a correspondingly high loss of income.
$400.00
Profit/Loss Year 2 of Coomandook NWS trial, no
treat costs
Profit / Loss ($) over control
$300.00
$200.00
$100.00
Control
MB
$0.00
-$100.00
Spader
APM
Cereal Control
CPM
Fert 1
Fert 2
Fert 3
Silage
TPR
Vetch
-$200.00
-$300.00
.
The data from year 1 and year 2 of the trial was then combined to give a cumulative profit/loss statement.
Control
Compost Pig
Manure
(10 t/ha)
Fert 1 (135
kg/ha DAP)
Fert 2 (270
kg/ha DAP)
Fert 3 (67.5
kg/ha DAP)
Triticale
Silage
(5 t/ha)
TPR (Grape
Marc, 20
t/ha)
Vetch
Hay, 5
t/ha
-$44.50
-$64.25
$0.00
-$133.00
-$67.63
-$114.75
-$188.06
-$279.00
-$906.50
MB
-$34.75
-$58.50
-$65.00
-$105.00
-$84.88
-$195.75
-$82.06
-$290.50
-$945.00
Spader
-$60.00
$11.00
$0.50
$9.25
-$64.37
-$57.00
-$118.81
-$326.25
-$903.25
Control
-$34.50
-$54.25
$0.00
-$123.00
-$57.63
-$104.75
-$178.06
-$269.00
$53.50
MB
-$24.75
-$48.50
-$65.00
-$95.00
-$74.88
-$185.75
-$72.06
-$280.50
$15.00
Spader
-$50.00
$21.00
$0.50
$19.25
-$54.37
-$47.00
-$108.81
-$316.25
$56.75
$1,462.00
$1,428.75
$1,451.50
$1,452.00
$1,418.75
$1,441.50
Control
$75.50
-$44.25
$0.00
$87.00
-$47.63
-$94.75
-$168.06
-$9.00
$63.50
-$142.00
MB
$85.25
-$38.50
-$65.00
$115.00
-$64.88
-$175.75
-$62.06
-$20.50
$25.00
-$108.75
Spader
$60.00
$31.00
$0.50
$229.25
-$44.37
-$37.00
-$98.81
-$56.25
$66.75
-$131.50
All costs
Control
No Transport
Costs
Cereal
Straw
(5 t/ha)
No OM Costs
Soil
Treat
Aged Pig
Manure (10
t/ha)
Profit/loss as a result of treatment after 2 years of crop.
When all costs are taken into account (cost of nutrition, transport, and spreading), most of the nutrition treatments
have still not shown a profit. Spaded straw and Spaded CPM are just above break-even, as is spading alone. The MB
plough has not reached break-even yet, although it has a lower cost/ha to implement, as the yields have not
increased as much as those with the spader. Vetch Hay is particularly bad as it has been priced at commercial rates.
The high cost of transport for the TPR (Grape Marc) causes that to show a large loss as well.
Cumulative P/L Year 2 (2014) Coomandook Trial
all costs
$200.00
$0.00
($200.00)
($400.00)
($600.00)
Control
MB
($800.00)
Spader
($1,000.00)
($1,200.00)
($1,400.00)
($1,600.00)
If transport costs are removed from the equation, then Grape Marc shows a small profit over the 2 years, with more
profit from grape marc with either spading or no soil modification. Spaded straw, spaded control or spaded CPM
have very small profits.
Cumulative P/L Year 2 (2014) Coomandook Trial
no trans costs
$200.00
$0.00
($200.00)
($400.00)
($600.00)
Control
MB
($800.00)
($1,000.00)
($1,200.00)
($1,400.00)
($1,600.00)
Spader
If the cost of organic matter is removed from the equation (ie free supply of compost, manure or hay/straw/silage),
then aged or composted Pig Manure and Grape Marc are all profitable. (Costs for granular fertiliser have been
retained.) Vetch hay is still down due to the yield suppression on the lupins causing a loss of income.
Cumulative P/L Year 2 (2014) Coomandook Trial
no OM costs
$250.00
$200.00
$150.00
$100.00
$50.00
Control
MB
$0.00
Spader
($50.00)
($100.00)
($150.00)
($200.00)
Key Points:




Spading has reached break-even at 2 years, compared to the control.
MB plough costs less initially, but is taking longer to pay for itself.
The profitability of compost, manure or plant matter depends greatly on the cost of the product and the cost
of transport. Generally, the cheapest closest decent source of nutrition is the most profitable, provided it is
able to be handled and used with machines available.
Adding OM with no soil modification has not shown an increase in profit so far. Although yields were
increased by OM in 2013 (barley crop), the increased income did not pay for the cost of the OM, transport
and spreading. In 2014, surface OM had no effect or led to a reduction on the lupin yield. This may be due to
the OM causing an increase in early growth with good nutrition in the topsoil, but the dry early spring meant
that crops with high biomass and shallow roots were affected more by the dry conditions, resulting in a loss
of yield.
Where to from here?



It would be great to be able to monitor the site for another year.
There is potential to look at ways of getting OM/slow release nutrition deeper into the soil without using
very disruptive processes – subsoiler, deep narrow point rig?
?