Latina™ Fresh and Landcare Australia Cover Crop and Stubble Manipulation Trials
In 2020, Landcare Australia and Latina™ Fresh, a General Mills brand, launched a series of agricultural trials. Conducted in partnership between Landcare Australia and the Northern Grower Alliance, the trials followed a needs analysis with durum wheat farmers in northwest NSW who indicated that they want to understand more about the benefits of cover crops and managing harvest stubble.
Cover Crop Trials
Cover crops can provide a range of potential benefits, including reduced erosion and weed growth, and improving nutrient availability in the soil. Recently they have also been adopted to increase fallow efficiency, which is the rainfall that is stored in the soil profile over a fallow period for subsequent crops to use.
Two trials to determine the benefits of cover cropping to support increased fallow efficiency, were undertaken at Rimanui Farms in northwest NSW. The results found that millet and sorghum performed better at increasing fallow efficiency and yield of the subsequent crop in the trial years. In the trials, the sorghum treatments resulted in the highest yields.
Stubble Height Management Trials
Previous research has highlighted that increasing stubble cover to reduce evaporation can significantly improve fallow efficiency. Stubble cover refers to crop residue left standing or on the soil surface after harvest.
Nine trials were launched to evaluate the impact of harvest stubble height on fallow efficiency and the performance of the following crop, however very wet seasonal conditions flooded the majority of the trials,with only three producing results.
The very wet season impacted the harvested trials, which showed no significant differences in fallow efficiency or subsequent crop performance from the variation in stubble height. Seasonal conditions with both lower rainfall prior to trial establishment and lower rainfall over the trial period may have provided significantly different results.
The Northern Grower Alliance is now looking to independently continue the cover cropping trials with the addition of Faba bean and Vetch in an effort to increase soil nitrogen and ground cover, guiding recommendations on fallow management and improving water use efficiency into the future.