Dr Daniel Hendrie1, Dr Stephen Akpa1, Mr Doug Crawford2, Prof. Roger Armstrong1
1Agriculture Victoria Research, Horsham, Australia, 2Agriculture Victoria Research, Ellinbank, Australia
Biography:
Daniel is a researcher in the Soil Sciences team at AVR in Horsham. His research focuses on spatially explicit amelioration of subsoil constraints to improve crop production and reduce yield gaps in Western Victorian cropping systems. He is also involved in developing screening procedures and identifying lentil germplasm with greater tolerance to soil acidity.
Abstract:
Subsoil amelioration has the potential to improve crop production in dryland cropping systems, but the high cost of application and uncertainty in crop responses limit practise uptake by grain growers. Multiple soil factors affect crop responses to subsoil amelioration, so we sought to determine if crop responses to subsoil amelioration can be optimised by delineating paddocks into zones to spatially manage the application of amendments, rather than ameliorating the whole paddock. Two soil types were identified in a medium rainfall zone paddock in western Victoria: a Sodosol and a sodic grey Vertosol. Five soil amelioration treatments (deep ripping, deep gypsum, surface and deep applied lucerne pellets with gypsum and deep fertiliser nutrients), plus a control, were applied in four randomised blocks in each of the two soil types in April 2021. Crop production and soil water use responses were then measured over the following three cropping seasons. Significant yield responses to amelioration occurred in the Sodosol every season, with relative yield increases of up to 66% for faba bean (2021), 58% for canola (2022) and 21% for wheat (2023). This corresponded to 70%, 42% and 32% increases in water use efficiency over these seasons, respectively. In contrast, no significant yield responses to soil amelioration occurred in the sodic Vertosol in any year and in some instances, yields were reduced. Therefore, the cost effectiveness of subsoil amelioration is highly dependent on targeting amelioration to only where soil conditions will result in the amelioration producing the greatest benefits.