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Soil-mapping techniques lauded

By Country News

Grain growers may one day soon be able to map soil in their paddocks without sending a single sample to the laboratory thanks to the efforts of an innovative young researcher.

Edward Jones is a post-doctoral research fellow from the University of Sydney, who is working on new technology with Grains Research and Development Corporation investment, examining how sensors can be used to scan soil for properties, such as clay content, water holding capacity, sodicity and pH.

His work has shown that by using a range of sensors to scan multiple soil samples across a paddock, it is possible to build an accurate digital soil map identifying variation within a paddock.

GRDC agronomy, soils and farming systems northern manager John Rochecouste said the ability to map soil types in paddocks, without sending samples to the laboratory, would be an invaluable management tool for grain growers and potentially save them significant costs.

‘‘Soil properties do not change rapidly, so once growers have developed a digital map it would become an important tool to guide their decision making and importantly it would not need to be updated annually,’’ Dr Rochecouste said.

‘‘Soil properties don’t change significantly for pretty much decades, if not longer, unless there has been major intervention such as incorporating significant amounts of lime or gypsum.

‘‘Things like sodicity and clay content are pretty fixed without intervention.

‘‘While pH can decrease (acidify) gradually with time, essentially they are pretty much fixed properties.

‘‘Nutritional element can vary significantly over seasons, so that’s why nutritional sampling is treated differently.’’

Dr Rochecouste said to 3D characterise a paddock was expensive in terms of sampling costs, so the work by Dr Jones was looking at significantly reducing this expense.

‘‘Knowing your soil characteristics across a paddock, and the variation within paddocks, is invaluable information and really is the foundation for effective crop planning and management,’’ he said.

‘‘However, there is a series of complex steps required to develop sensors, which can effectively calculate soil properties.’’

Dr Jones has been trialling the new sensors and digital soil mapping techniques at a research property at Narrabri in NSW.

His plan is to showcase these digital technologies destined for broadacre agriculture to growers, farm advisers and industry stakeholders at a field day early next year.

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