Australia
June 16, 2017

USQ soil scientist David Freebairn is recommending growers try an effective, but simple-to-use SoilWater app to assist in determining their moisture profiles this season

Grain growers in Queensland and New South Wales are increasingly concerned about the winter crop weather forecast, with dry conditions showing little sign of easing.

University of Southern Queensland soil scientist David Freebairn said while weather forecasting can provide some insight into conditions, growers can determine with reasonable certainty the level of sub-soil moisture in their profile through the use of new technologies.

“Forecasts are prone to false positives and false negatives in terms of how growers see the season progressing, but that doesn’t have to be the case in monitoring plant available soil water,” Dr Freebairn said.

“A Grains Research and Development Corporation investment, the SoilWater app uses a water-balance model to calculate water inflows and outflows through a soil profile on a daily basis.

“Local weather data including rainfall, temperature, solar radiation and evaporation are used to simulate crop growth, runoff, drainage and stored moisture levels in each soil layer.”

Dr Freebairn said the SoilWater app is currently showing that despite the lack of rain, many regions in Queensland are looking relatively positive in terms of plant available water.

“A quick look for Chinchilla and Dulacca, both locations with similar soil types, show that Chinchilla is sitting on about 24 per cent of a full profile while Dulacca has 86 per cent, demonstrating how variable rainfall can be within a region,” he said.

“In New South Wales we can see Dubbo is sitting on 71 per cent, which is similar to last year and slightly above average, but Wagga is well below average at nine per cent. Then 60km down the road at Henty, the profile is at 17 per cent again demonstrating how significant the difference can be within a region.

“Checking these percentages takes less than a minute as the SoilWater app automatically updates rainfall from the nearest Bureau of Meteorology station and rainfall for a local rain gauge can be simply added.”

Dr Freebairn said that SoilWater app is a spin-off from the popular CliMate app, which has been downloaded 20,000 times and is roughly used 5000 times a month.

“SoilWater just reached its 1000 download, and is being used about 500 times a month, predominately by agronomists, but my message is that the simplicity of this platform means it’s valuable to growers too,” he said.

“You can set it up to monitor soil conditions from last winter’s harvest, so it not only gives you the profile at time of sowing, but also as that season progresses.”

“SoilWater considers all components of the water cycle on a daily basis and also uses long term climate data to provide a forward-looking estimate of likely outcomes for the specified soil, location and fallow/crop conditions.”

Winter cereals and pulses grown in the summer cropping zones of Queensland and northern NSW are particularly dependent on water stored during fallow.

“This means that these crops in particular can benefit from monitoring with the app. Up to 70 per cent of a winter crop’s moisture in Central Queensland can be derived from water in the soil at planting,” Dr Freebairn said.

“Even small amounts of water can make a large difference to crop yields by reducing stress in critical periods.

“Growers will even have the capacity to monitor from paddock to paddock, meaning local differences in soil type and management will be accounted for, and so its use for in-crop management is effective too.”

Visit http://www.soilwaterapp.net.au/ to read more about the app, which can be downloaded from the App store.

Growers can learn more about plant available water with the GRDC Manual, Estimating Plant Available Water Capacity which can be found on the GRDC website or via this link.

 

Website: http://www.grdc.com.au

Published: June 16, 2017