A REDUCTION in fertiliser applications of up to 50 per cent is one way Mt Ney producer, Tom Brown is producing crops under variable climatic conditions.
Mr Brown has seen the cost of fertiliser and chemicals rise and is keen to tailor the level of inputs to the potential seasonal conditions.
He crops about 4500 hectares, 85 kilometres north east of Esperance in southern Western Australia, growing canola, wheat, barley and more recently, field peas.
He sees nitrogen-fixing crops as one way to reduce his fertiliser bill.
“Peas will become a greater proportion of the cropping program to make sure I have a nitrogen-fixing crop in the mix and also have a break crop in place,” Mr Brown said.
“I’m also playing around with a little bit of clover which I’m looking at mulching rather than harvesting.”
Soil type and moisture are two other factors which Mr Brown believes have a major impact on the efficient use of fertilisers.
He has found the problem of non-wetting soils on the farm has been increasing.
“I have noticed this is getting worse and worse and I would say 10-20pc of the property has a non-wetting soil problem,” Mr Brown said.
“We’re looking at various ways of combating it from a wetting agent behind the bar, to a trickle down the centre of the press wheel run to try and get that wetting up on the first three or four millimetres after we finish seeding.
“I’m also examining claying some of the worst areas on the property.”
The other area Mr Brown is examining is the application of variable rate technology on his property to optimise the fertiliser use.
There is a trial in one of his paddocks being conducted by local agronomists and the CSIRO, with funding from the Grains Research and Development Corporation (GRDC).
“Certainly for the savings there is no point in putting too much seed and fertiliser on areas which just don’t return the yield,” Mr Brown said.
“We have a fairly large experiment happening this year but I’m also listening to what other people are doing as well.”
The trial paddock on the Mt Ney property has seen a 40-50pc variation in the MAP starter fertiliser used during this year’s planting.
There has also been a small increase in the urea application to try and keep the nitrogen level consistent across the paddock.
Researchers have included some very high fertiliser strips and some very low fertiliser strips through the paddock and hope to pick a variation between the two.
“The computer certainly showed that we did have a fairly large saving on the amount of MAP we used,” Mr Brown said.
“I’ll be looking forward to work out the performance once we have yield mapped it this year.
“The researchers use pretty sophisticated software and they’ll be able to analyse my yield maps far better than I’m able to do myself.”
Mr Brown said he expected to find out whether he could push a better yield without increasing input costs from this year’s variable rate experiment.
Like much of southern WA, the 2009/2010 summer was amongst the driest on record and there was a tough start to the winter cropping program.
This has prompted an expansion of the fertiliser trial to determine the impact of summer rainfall and hence stored soil moisture on the winter crop’s performance.
“The researchers brought out 16 small tanks and half-filled them with water and placed a little soaker hose out from the bottom of those and covered them all with black plastic,” Mr Brown said.
“They filled the very small areas with a fair bit of moisture as they topped up those tanks twice.”
Before the water was applied, the area was drilled and core tested to determine the level of available moisture for the plants.
The researchers then went back and core tested the same areas after the black plastic was lifted and the tanks removed.
“They have analysed the difference between the two core tests and I’ve seen the electro magnetic survey – the results very interesting,” Mr Brown said.
A challenge with the research was that each of the areas to receive water was less than two metres wide, so the core samples and electro magnetic surveys are the only data which can be used.
“We are not going to be able to yield map the very small areas they soaked but I’m sure in the future it will be very interesting to observe this paddock.” Mr Brown said.
“If we have a low rainfall year and we stay on the drier side, I expect we will start seeing some pretty strong differences in the crop growth where they had their soaker hoses as opposed to where they didn’t.”
Mr Brown hopes to use the results of this study to tie in with the Department of Agriculture and Food WA (DAFWA) long range weather prediction system.
“If we come out of a fairly wet summer and we have a lot of available moisture in the soil, I hope to be able to apply more fertiliser onto the following crop than if we have a dry summer period,” Mr Brown said.
“When we can check the moisture with core testing as we have been done this year and there is good soil moisture we can place a bit more fertiliser on at planting.
“Even if they forecast a drier winter, if we get about 100mm of available moisture in the soil, we can still grow a good crop.
“That will make a big difference to the crop we can grow and in the past we didn’t know that potential was there and our yields suffered.”
Mr Brown hopes the trial will provide knowledge that will allow him to realise a lot more yield from some of the better soil types.
“In the future it’s potentially going to be a much more profitable way to grow crops in the better years and in the poorer seasons we can cut back inputs,” he said.
“If DAFWA is telling us we are going to have a drier than average winter, then we’ll look at cutting our fertiliser rates back.
“On the other hand, if we have had good summer rainfall and are expecting an average winter, then we would look at pushing the production system to try and produce a bigger crop.
“I’m keen to yield map it correctly and get the information right so we can improve crop performance by one, two or up to ten per cent.”
For more information, visit www.grdc.com.au.
