HOW TO balance low rainfall and profits and come up with the right level of management inputs - that was the challenge WA's Liebe Group set itself in trials last season.
The ' Practice for Profit' trials, based at Ron Carlshausen' s property 'Namron Downs' 5 km south of Wubin, aimed to evaluate the gross margins returned from crops of Arrino and Calingiri wheat with low, medium and high rates of inputs at the time of sowing. The year received only 181 mm of the 'normal' 250 mm of growing season rainfall.
The study demonstrated how risky it can be to apply high inputs at sowing time based on assumed average to above-average seasonal conditions. "This season in a highly productive paddock with a good fertiliser history and low weed burden, the dollars spent on in puts would have been best left in the bank," said Liebe Group coordinator Amanda Just. She suggests that long-range weather forecasts can give growers some indication of the likely season.
Low-input treatments were based on a farmer delivering grain to the bin at the lowest possible cost, regardless of seasonal conditions. Only the basic pre-sowing inputs, such as the minimum rates of herbicides and DAP fertiliser, were applied. Medium inputs were set to district practice in the Liebe Group area. High-input treatments were based on what could be expected from a grower who wanted to spend more than the district average to aim for bumper yields from a well set-up paddock. (The inputs for each of the treatments are shown in the table.)
Because of the very dry season, postseeding applications of post-seeding inputs such as foliar fungicides, insecticides and extraurea of the higher management packages were not applied because of the lack of yield potential, soil moisture and low incidence of disease.
Yields remained low
Crop emergence, crop vigour, tiller counts and head counts in both wheat varieties were better in the high-input treatments than in any of the other treatments. However, the yields were still low at 2 t/ha, and Ms Just says a modest increasc in yield from higher inputs did not justify the extra cost.
"The only significant yield difference was the high-input treatment of Arrino, which outyielded the low-input treatment of Arrino by a mere 300 kg/ha," Ms Just said.
Calingiri yields were the same for all three input treatments. According to Ms Just, the dry season prevented both Arrino and Calingiri from achieving the yield potentials that were being targeted at higher input levels.
As well as no real effect on yields, there was also no real difference in grain quality as a result of the level of input. However, protein levels did differ sign ificantly for both Arrino and Calingiri.
Noodle grade a concern
"The medium and high inputs gave us grain protein levels that took the crop out of the noodle grade." Mr Carlshausen said. Only the low-input treat ments achieved the ASWN payment grade. This is the main reason they gave the best gross margins."
Mr Carlshausen manages most of his property with input rates that are at the medium level used in the trials - at district practice. He avoided the price penalty from high protein levels by assessing the grains off each paddock and blending them to get into the right noodle grade with the right parameters of protein and screening.
"The lesson for us is that we now look a lot more closely at the costs of production of each paddock and the management inputs that we should apply to each," he said. "Although, we have never gone for high inputs, except for the better paddocks where we would expect better yields.
Weed control not big issue in these trials
" In the trial a rea we didn't have a big problem with ryegrass or wild radish and so we didn't have to spend a lot on control," adds Mr Carlshausen.
This was co nfirmed by the low but variable counts of wild radish in the trials, with the weed more commonly found near the fence regardless of treatment. Even so, Ms Just says that a spray treatment was necessary on the trial plots because the radish was quite thick where it had emerged. Pre-emergent herbicides failed to control wild radish, but all post-emergent herbicides achieved complete control.
The trials also suffered little from ryegrass invasion. The low-input treatments were most severely affected, but at only 17.8 and 16.7 plants per square metre, the amount of ryegrass was considered unlikely to have an influence on yield. "We think the difference in ryegrass control in the trials might be because of the different pre-emergent herbicides used in the three input treatments," says Ms Just.
Dry season effects this time but trials to continue
Both Mr Carl shausen and Ms Just attribute the overall profitability of the low-input treatments directly to the dry season. In a wetter or even a 'normal ' season, the results could be very different and this is why the Liebe Group want to run the trials over 10 years.
Rates of management inputs for Arrino and Calingiri wheat treatments
|Input||Treatment (rate) Low||Medium (District)||High|
|Seeding rate||50 kg/ha||70 kg/ha||100 kg/ha|
|Seed dressing||Nil seed dressing||Premis 100ml/100kg||Real 150 ml/100 kg (Arrino) Premis 150 ml/100kg (Calingiri)|
Glyphosate 1 L/ha
Glean 10 g/ha
MCPA 400 ml/ha
Diuron 350 ml/ha
Glyphosate 1 Uha
Trifluralin 1.5 Uha
Logran 35 g/ha
2,4-0 Amine 1 L/ha
Glyphosate 1 L/ha
Trifluralin 1.5 L/ha
Logran 35 g/ha
Tigrex 500 ml/ha
|Fertiliser||DAP 50 kg/ha|
Agstar 100 kg/ha
Urea 50 kg/ha
Agstar 140 kg/ha
Urea 80 kg/ha
Coptrel 250 ml/ha
MOP 80 kg/ha
|Spraying/spreading||2 operations||3 operations||5 operations|
|TOTAL INPUT COSTS||$49.80||$115.37/ha|
Yields, grain quality and gross margins for Arrino and Calingiri wheat input triats at Liebe
|Input||Grain yield (t/ha)||Grain protein (%)||Grain weight (kg/hL)||Grain screenings (%)||AWB payment Grade||Total return ($/ha)||Total return treatments ($/ha)|
|Low input||1.830 b||11.70 bc||81.43 b||0.18 cd||ASWN||$426.91 b||$381.31 b|
|Medium input||2.002 ab||12.63 ab||82.35 a||0.12 d||ASW||$461.38 ab||$355.45 b|
|High input||2.131 a||13.17 a||80.38 c||0.23 c||ASW||$490.50 a|| $267.58 c|
|Low input||1.928 a||10.67 c||82.92 a||0.59 a||ASWN||$493.03 a||$418.98 a|
|Medium input||2.074 a||12.93 ab||82.49 a||0.35 b||ASW||$476.75 a||$322.58 b|
|Data followed by same letter do not significantly differ (P=0.05, LSD)|
Acknow ledgements: Farm
Contact: Ms Amanda Just 08 9664 2030 emait email@example.com