App calculates rainfall effectiveness
An app that marries grower knowledge with weather and soil data is being fine-tuned to give growers a tool to help make cropping decisions such as whether to plant or fallow, or how much nitrogen to apply.
The SoilWater App has been developed with GRDC funding by the University of Southern Queensland’s National Centre for Engineering in Agriculture in Toowoomba.
The app works by overlaying Bureau of Meteorology data with on-farm rainfall figures and soil-type information.
Project leader Dr Brett Robinson says the app calculates the effectiveness of rainfall and its implications for a following crop. It estimates soil water availability by analysing rainfall, climate, soil and paddock-management information, and can incorporate data from soil-water sensors. The app produces a graph that shows whether the soil water is near the surface or deep in the profile or both, and the distance between subsoil and surface moisture if there is a dry band between.
“We have had these models of rainfall and soil water on our big clunky computers for a long time, and growers have the experience and paddock knowledge to interpret their rainfall patterns. Now they can be brought together on a phone in the paddock,” Dr Robinson says.
The app allows growers to select more than one soil type per paddock and can incorporate data from more than one rain gauge if rainfall is variable across a paddock.
“It uses work done by CSIRO on soil descriptions and gives users a menu of about 20 soil types in each state so they can accurately select which ones they have.”
The app requires a starting moisture value, given as a percentage of a full profile at the beginning of fallow, and then looks at climate and rainfall data over the fallow period. It can also incorporate estimates of soil water from sources such as electromagnetic mapping, capacitance probes and soil coring.
Dr Robinson says the app can be used to avoid overspending on crop nutrition when the season’s start is tough, or under-nourishing when prospects for a big yield are high.
“A profile that’s nearly full is one of the most important signals for higher inputs in terms of the crop nutrition and crop protection that are needed to get maximum yield. You might need 60 or 80 units of nitrogen per hectare instead of 40 on average, or if it’s a poor start, then only 20.”
The app is being trialled by 50 growers across Australia. It is scheduled to be available through the Apple Store later this year.
More information:Liz Wells
University of Southern Queensland
07 4630 8863
GRDC Project Code USQ00014