Improving pasture yield
Agriculture Victoria researchers have developed a new, more cost-effective method for farmers to determine soilwater properties.
Accurate soil-water information can vastly improve crop and pasture growth predictions.
Soil-water data determines a plant’s capacity to extract moisture from a soil profile and can be used to inform crop yield or pasture growth, thereby influencing crop choice and management.
Getting this soil-water data through direct infield measurement supported by laboratory analysis is expensive and time consuming.
The new technique uses state-of-the-art field and laboratory methods and mathematical functions to gather soil-water data, allowing farmers to derive their own soil-water information from cheap and easy-to-measure soil properties.
Enhanced soil characterisation will enable increased accuracy in predictions of:
Paddock to catchment scale soil moisture status;
Increase in grain production associated with improved farming practices; and
Grain loss due to heat stress associated with extreme weather conditions; and water-logging.
Croppers and graziers of Victoria will now be able to determine the upper and lower limit of water storage of the soil profile and the rate of water movement through the soil profile at the paddock level by using a simple description of their soil profile.
Using this soil-water data as an input into the yield prophet model, the Agricultural Production Systems sIMulator (APSIM) will enable farmers to improve the prediction of crop yield.
Agriculture Victoria Senior Researcher Dr Abdur Rab said based on seasonal rainfall forecasting, farmers would be able to better predict grain yield’ informing a range of decisions; for example, whether to sow crops or not.
“The new soil hydrological data and method could increase accuracy of predictions by 4050 per cent in areas where only limited information about soil composition or soil type is available,” Dr Rab said.
In addition to these new methods, this project will also provide base-line data on soilwater for major soil types and cropping management systems; for example, no till or control traffic.
Dr Rab said using this base-line data, farmers would be able to determine which soil properties may limit crop growth.
“This exciting development will inform what type of cropping management or soil types are better in terms of retaining soil-water, and how fast or slow water moves through the soil profile.”
The soil-water information is also essential for environmental, hydrological or land surface models, including weather forecasting, surface water flow and groundwater, and flooding.
Although this new soil data has been determined for the conditions of dryland cropping soils of north-western Victoria and some high rainfall dairy and sheep grazing pasture and cropping soils, it may be applicable to other regions of similar soil and climatic conditions.