Overcoming constraints to the profitability of cropping systems on ironstone gravel soils within the Southern cropping region of Australia. - Phase 2

The idea for increased profitability on ironstone gravel soils originated from the Albany and Kwinana west port zone within the western region, however, is it applicable to a wider area of the southern cropping region. Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, and which contains a substantial proportion of iron compounds (> 15%). The term ironstone gravel is loosely defined, as it covers a broad range of gravel soils which are located predominantly within the medium to high rainfall zones of the western region, lower Eyre Peninsula and on Kangaroo Island in the southern region. It is estimated that more than 2 million hectares of these soils are used for agricultural production in both regions. Ironstone gravels are important cropping soils and a better understanding of their properties and management is urgently required to improve crop production.

The properties of these soils are poorly understood; however, two major constraints have been identified in a scoping study, which are low plant available water and extremely high P fixation. Establishing the physical distribution of these soils, as well as their chemical properties, iron content, particle size and topography, is being undertaken to better understand the extent of the constraints in these soils (UWA1906-008RTX).

Once detailed understanding of the mineralogy of these soils has been achieved, the focus of this proposed investment will be to relate this new knowledge to mineralogy, hydrology, root architecture and P availability and interaction with crop performance and profitability. The next phase is to build and exploit this information and develop an understanding of crop production on these soils. This understanding will be used to identify the links between soil properties including mineralogy and chemistry to develop tools, methods and technologies to increase P and moisture availability to canola and wheat crops. The use of innovative techniques and approaches, using technology from mining and other industries, will potentially provide growers with transformational tools to increase profitability on these soils.

This new investment will build on the new knowledge and work conducted by the current investment (UWA1906-008RTX).