Growers are seeking to better understand which components are key to managing the system and what some of the potential trade-offs might be around transitioning to a strip and disc system in local soils which include large areas of alkaline and sandy soils. It was hypothesised that the use of strip and disc systems (which reduce evaporation), may contribute to significant yield improvements in years with summer and early autumn rain.

Growers believed there were opportunities for strip and disc systems to minimise soil disturbance, conserve more soil moisture, improve logistics (particularly speed of operations), and potentially improve yields. However, some of the challenges such as the impact of high stubble on summer spray efficacy, an improved pest habitat for snails, mice, and weeds, extra investment into machinery, differing herbicide options for discs with differing amounts of soil throw and integration of livestock, needed further investigation.

• Large plots of stripper stubble and two heights of conventional stubble were set up during the harvest of 2023 at Cleve and Minnipa to measure their effects on soil water evaporation using soil moisture probes.
• Various herbicide strategies have been implemented across the three stubble types to measure the effect of summer weeds on soil water losses over summer.
• The different stubble systems will be sown in 2024 by disc.

Replicated broadacre stubble management treatments were implemented using growers’ harvester fronts in November 2023. The Minnipa site was implemented over two soil types, a red loam flat and a sandhill to capture differences in soil moisture on the different soil types.