Ms Kanch Wickramarachchi1, Dr Gaus Azam1
1DPIRD-WA, Northam, Australia, 2DPIRD-WA, Northam, Australia
Biography:
Kanch Wickramarachchi, a research scientist of DPIRD WA, has been playing a pivotal role in the Soil Reengineering Project, jointly invested in by DPIRD and GRDC, aiming to enhance crop root systems' access to water and nutrients stored in deep subsoils. Leveraging her extensive research background, Kanch conducts controlled environment studies complementing ongoing field trials. Her research delves into the impact of soil reengineering on crop root development and crop growth, teasing out the nuances of complex plant-soil interactions present in field trials. With a fervent dedication and extensive experience in root phenotyping, Kanch contributes to advancing soil reengineering research
Abstract:
Extending the root systems of crops beyond the typical depths achieved in prevailing field conditions can enhance their ability to access moisture and nutrients from deeper subsoils, thereby improving crop water use efficiency in arid and semi-arid climates in Western Australia (WA). However, prevalent subsoil constraints in WA, such as compaction and acidity, hinder the development of deep root systems. Duplex soils, common in the region, exacerbate these challenges, leading to suboptimal yields.
A field trial of soil reengineering experiments involving soil loosening and the incorporation of different ameliorants to a depth of 80 cm in a duplex soil profile with subsoil acidity and compaction reported that barley yields could be doubled by deep incorporation of lime, fertiliser, and clay compared to the surface application of the ameliorants. However, the deep incorporation of fertiliser to an 80 cm depth presents practical challenges in the annual replenishment of nutrients based on crop demand.
The current semi-controlled environment study investigates the effect of fertiliser placement (surface or deep incorporation) at different rates on shoot and root growth of a barley crop grown in a re-engineered (decompacted and lime incorporated to an 80 cm depth) duplex soil. The second phase of the study examines different rates of surface-applied nitrogen on barley crop yield on the above reengineered profile. The findings will inform optimised fertiliser management practices, thereby contributing to sustainable agriculture in water-limited environments and advancing the sustainable intensification of crop production for a resilient future.