WAYS to get the best yields from poor performing sandy rises, in the most profitable manner, are being explored through a Lowbank & Districts Agricultural Bureau project.
Early results of the project – Sand improvement through manure profiling in low rainfall Northern Mallee – were on show at a recent trial inspection and crop walk day run by the bureau at Waikerie.
Often, differences in trial treatments are not evident until the crops are harvested and analysed but there were obvious variations shown during the crop walk.
Lowbank Agriculture Bureau chairman Brenton Kroehn said the project targeted a common issue in the district.
"The tops of sandhills are not yielding as well as the flats, they could be half the yield on the top than on the bottom," he said.
The project is being run on local farmer David Schmidt's property.
The trial was sown on April 29 and the paddock has a history of continuous cereal cropping.
"The hills are poor and they go down to our heavy flats," Mr Schmidt said.
"The paddock was summer sprayed once and then sown with Kord wheat.
"There were 55 kilograms a hectare of Kord wheat sown, along with 60kg of 15:13:11 fertiliser and urea, and the whole paddock was EM mapped.
"It was sown with a Seed Hawk (seeder) on 33 centimetre spacings with paired rows."
By July 20, the paddock had received 102 millimetres of rainfall for the year, with 36mm falling in January and 66mm in the growing season.
The trial work is being undertaken by Insight Extension for Agriculture's Chris McDonough.
Each plot Mr McDonough has set up is 15 metres wide and goes for 400m, over two sand hills and through loamy soils as well, with the trial fully replicated.
Moisture probes will help monitor the depth of rain penetration and crop water use under the various treatments.
The cost of treatments have generally been kept to a level that even with a 0.5 tonnes/ha yield increase there will be a return on investment in less than three years.
Fifteen different treatments range from a control right through to a 'kitchen sink' treatment.
"The kitchen sink treatment has the lot – chicken manure, spading, clay spreading, high granular fertiliser and trace elements – just everything thrown at it," Mr McDonough said.
"While it wouldn't be economical on a large scale, it is interesting to see the results."
The trial is exploring the difference between surface spreading various treatments, which is easier and less expensive, against the value of deep-working nutrients and organic matter through spading and deep ripping.
Mr McDonough said working out how long it took to pay for farm treatments was an important part of the project.
"Once you work out your cost a hectare, you can start to work out how many years of benefits it will take to pay for the treatments," he said.
He said one of the treatments that looked most promising and profitable was putting out 2.5t/ha of chicken manure and spading it.
At a cost of about $200/ha, it would take two years to return if a 0.5t/ha yield increase was achieved.
Mr McDonough said the cost of chicken manure had become more affordable, with the increase in chicken farms in the area.
"At a cost of about $30/t for chicken manure, if you can pick up 0.5/ha of extra yield, it won't take long to repay the initial cost," he said.
"We need to see if there's long-lasting benefits, and get good data on those benefits to see if it's worth the cost.
"But, I think putting out 2.5t/ha of chicken manure and spading it into the ground could be a real option for this area. However, the initial risk of wind erosion of newly spaded light sands should not be overlooked. This may be reduced by rolling and establishing crop cover as quickly as possible."
