Maximising fallow rotations with a Strip and Disc strategy to increase water use efficiency and subsequent crop yields in the central eastern wheatbelt region of WA

Overall Objective

This project aims to provide grain growers across the wheatbelt region with stubble management strategies utilising a ‘strip and disc’ system which incorporates a chemical fallow rotation to increase soil moisture retention for maximum yield potential in the subsequent cropping season.

This project will establish a farmer-scale trial located in the central to eastern wheatbelt region, to examine the effects of utilising a ‘strip and disc’ strategy with chemical fallow compared to the typically used ‘draper front and tyne’ sowing across the wheatbelt over the two year trial. This project will assess both agronomic and economic outcomes for WA growers.

Project Synopsis

This project was delivered by the Corrigin Farm Improvement Group (CFIG) and supported/funded by The Council of Grain Grower Organisations (COGGO).It was successful in providing insight into stubble management strategies utilising a ‘strip and disc’ system (harvesting with a stripper front and seeding with a tyne system).  A chemical fallow rotation was incorporated to increase soil moisture retention for maximum yield potential in the subsequent cropping season. The strip and disc system focuses on minimised soil disturbance for moisture conservation.

This project utilised a farmer-scale trial located in the central to eastern wheatbelt region, to examine the effects of utilising a ‘strip and disc’ strategy with chemical fallow compared to the typically used ‘draper front and tyne’ (harvesting with a draper front and seeding with a tyne system) sowing across the wheatbelt over the two-year trial. The draper/tyne system incorporates the traditional soil disturbance method.

This project assessed both agronomic and economic outcomes for WA growers. Included in the assessment of outcomes was grain yield, quality, machinery efficiency, soil moisture retention and weed populations.

The key takeaways from the project where:

In respect to yield, the Draper/Tyne system was slightly higher (4.52 t/ha in 2022 vs. 4.47 t/ha for Disc/Stripper). However, the difference was small (less than 5%), likely due to high rainfall in 2022.

The Disc/Stripper System however had higher grain quality (higher hectoliter weight, lower screenings, higher protein) giving a higher price/gross return.

The soil moisture retention was higher in the Disc/Stripper system which is of high importance in the low rainfall zones.  Soil moisture was higher both pre- and post-harvest. Disc/Stripper also retained 16% more moisture post-fallow, showing the Disc Stripper System having improved moisture retention especially in drier years.

The weed density was also lower and in regard to machinery efficiency, the Disc/Stripper system was twice as fast and more fuel efficient.

• For high-rainfall years, both systems perform similarly.
• For dry years, the Disc/Stripper system is expected to outperform.
• For economic efficiency, the Disc/Stripper system saves fuel, time, and reduces chemical costs.
• Overall, the Disc/Stripper system provides more advantages for long-term sustainability, especially in lower rainfall conditions.