Landscape evaluations help make precision ag pay

Precision agriculture can show a grower zones of variability in a field, but this has little link to improving profits unless they can understand the reasons behind variability and what they can do about it.

One of the program's founders, Terrabyte consultant and now Graham Centre researcher, Jonathan Medway, said he believed there was a surge of interest in how to make sense of precision agriculture.

"Farmers have gradually replaced their harvesters or tractors and the equipment to do spatial management is usually part of the tractor now," Mr Medway said.

"It's not as optional as it used to be so farmers are increasingly asking 'well how do we make use of this technology?'."

Mr Medway said for the past 10 to 15 years, most precision farming decisions have been based on single factors.

"A single piece of yield data is used to make agronomic decisions, where in fact most agronomy requires lots of different layers of information," Mr Medway said.

"The program we have developed has used as much information as we can access from the past 10-15 years to more robustly spatially analyse the trends in crop production and then go out and do a landscape evaluation of what's driving those changes."

Mr Medway said the landscape evaluation began with an international standardised soil profile description.

"We're taking soil cores down to a metre and describing the soil in terms of characteristics like clay content, inferred water holding capacity, dispersion and pH," Mr Medway said.

He said they then look at how the soils fit into the landscape, for example considering whether they're on a side slope, top of a hill, or drainage line.

"We can make some generic assessments about the types of soils we have in the different zones, then working with the agronomist and the farmer we can come up with a strategic plan to investigate what the best management options are going to be," Mr Medway said.

Working alongside Mr Medway is Peter and Hazel McInerney from 3D Ag.

Mr McInerney said profitability in farming was slipping all the time.

"Expenses in farming are going up and as we deal with that in a more volatile climate, we really need to make sure we're not just taking our money down to the casino," Mr McInerney said.

"Growers need to do everything they can to get their inputs in the right places for the best return.

"A hectare of land that grows two tonne of wheat per hectare costs you the same amount of money as the one that grows you 4t/ha."

He said they already have several properties undertaking the program and they were seeing results.

"On one property there was a 123ha field and the average saving was over $50/ha. That's more than $6000 for one field," he said.

"One of our long-term clients is on their fourth lap around their farm, looking at progressively applying varying rates of animal manures to try and remove variation in the soil, increase organic ground matter and feed the microbiology.

"The client's harvesting contractor comes in and says his crops are becoming more uniform every year.

"On that farm we're lifting the lower performing areas, the higher performing areas might stay the same.

"The client is now further refining his input decisions based on the zone information provided by PIP."

Mr McInerney said the solutions for different clients and even different parts of a field can vary significantly, making a tailored approach relevant.

"Animal manure is what we're looking at there, but we could also easily be looking at lime, gypsum or variable rate fertiliser inputs. There are a number of solutions when we know what the problem is," Mr McInerney said.