Dr Gaus Azam1, Kanch Wickramarachchi1, Hasin Rahman1, Md Shahinur Rahman1, Chad Reynold1, Glenn McDonald1, Wayne Parker1, David Hall1, Craig Scanlan1, Steve Davies1, Chris Gazey1
1DPIRD, Northam, Australia
Biography:
With the Department of Primary Industries and Regional Development (DPIRD), Dr Gaus Azam leads a GRDC funded re-engineering soils project, addressing multiple interacting soil constraints in the crop root zone through combining innovative soil amelioration techniques and soil profile reengineering. Previously, Gaus successfully managed a DPIRD/GRDC-funded project developing innovative approaches to manage subsoil acidity in the western regions. He has a PhD from the University of Adelaide and has over 15 years of research experience in various areas including soil science, agronomy, and crop physiology. Gaus received GRDC's prestigious award 'Recognising and Rewarding Research Excellence' in 2023.
Abstract:
Unpredictable climatic events such as wet winters and dry hot springs are increasingly common, threatening the sustainability of the grains industry. Existing literature suggests that deep soil amelioration and re-engineering might double the grain yield and water use efficiency (WUE), particularly in more favourable seasons. However, the crucial question remains: will these enhancements endure during low decile seasons? To address this inquiry, we investigated five experiments over three seasons at Kalannie, Bolgart, Meenar, Badgin, and Tarin Rock in Western Australia.
The average growing season rainfall for these sites in 2021, 2022, and 2023 were 371 mm, 386 mm, and 185 mm, respectively, with estimated water-limited yield potentials for cereal crops were 5.56 t/ha, 5.76 t/ha, and 1.89 t/ha for the same periods. Our findings reveal that the improvements in soil properties persisted for three seasons and are expected to last for a longer period. The average grain yield and WUE of major crops exhibited significant increases, rising by 2.1-, 1.7-, and 1.9-fold across the 2021, 2022, and 2023 seasons, respectively. The maximum recorded yield improvements were 2.0 t/ha, 2.7 t/ha, and 2.1 t/ha for wheat, barley, and canola, respectively, compared to the control.
While yield enhancements were more pronounced during wetter seasons (2021 and 2022), WUE demonstrated higher performance during the drier season (2023). It is anticipated that upon adoption by grain growers, the insights gained from re-engineering soil research will unlock the potential for achieving a new frontier in grain yield and WUE in WA.