With dry conditions in Queensland and New South Wales showing little sign of easing, grain growers in these regions are encouraged to try an effective but simple-to-use app to assist in determining their soil moisture profiles this season.
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.
The new SoilWater app uses a water-balance model to calculate water inflows and outflows through a soil profile on a daily basis, Dr Freebairn explained.
“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.”
For example, 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,” Dr Freebairn demonstrated.
“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.”
The app automatically updates rainfall from the nearest Bureau of Meteorology station and rainfall for a local rain gauge can be easily added. 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.
The SoilWater app can be set up to monitor soil conditions from the previous winter’s harvest, providing growers with the profile at time of sowing and throughout the progress of the season. Furthermore, it considers all components of the water cycle on a daily basis,?using long term climate data to provide a forward-looking estimate of likely outcomes for the specified soil, location and fallow/crop conditions.
Dr Freebairn said that crops, in particular winter cereals and pulses grown in the summer cropping zones of Queensland and northern NSW – and dependent on water stored during fallow – 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 and even small amounts of water can make a large difference to crop yields by reducing stress in critical periods,” Dr Freebairn said.
“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.”