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Farmers in southwest Western Australia will welcome research published by researchers at The University of Western Australia and grower groups, which suggests that light grazing of sheep on crop residues over summer has little impact on the following no-tillage crops.

Dr Ken Flower from UWA’s School of Plant Biology and Institute of Agriculture led the study to determine if summer grazing of residue impacts the following crop yields in the no-tillage system.

Thirteen farm trial sites were used: with six in Western Australia spread across four farms at Cunderdin, Yealering, Meckering and Wickepin; four in northern Victoria at Banyena, Ultima, Hopetoun and Quantong; and three in southern Victoria in Inverleigh, Lake Bolac and Werneth. The results showed that light grazing of sheep on crop residues had no significant effect on the amount of residue, soil properties, soil water, weeds or yield in the following crop. The main effect of grazing was to knock down and scatter the standing crop residues.

Crop residue is seen by many farmers as a valuable livestock feed; however, soil cover provided by crop residues is a key component of conservation agriculture for maintaining favourable soil structure and high yields.

Dr Flower said this has led to the perception that no-till is incompatible with livestock grazing of residue due to the effect on soil cover and perceived problems including trampling, compaction and reduced infiltration, weed seed burial and transport and erosion.

“Most farmers still consider it important to maintain livestock for a more sustainable and diverse system, as a result of reduced economic risk and greater flexibility in weed control with the use of pastures,” Dr Flower said.

“In Western Australia, the majority of producers have adopted conservation farming methods so these results will give confidence to farmers to utilise stubble in their no-tillage systems.”

The findings were published in the paper Light grazing of crop residues by sheep in a Mediterranean-type environment has little impact on following no-tillage crops in the European Journal of Agronomy. The collaborating groups were WANTFA, Facey Group, Birchip Cropping Group, CSIRO, Falkiner Ag Pty Ltd, Mallee Focus and Nicon Rural Services Pty Ltd. The research was funded by the Grains Research and Development Corporation (GRDC) and the Australian Government’s Caring for our Country initiative through the Grain and Graze 2 project, with assistance from the Australian Centre for International Agricultural Research (ACIAR).

Media references

Dr Ken Flower (+61 8) 6488 4576

Diana Boykett (Communications Officer, The UWA Institute of Agriculture)

(+61 8) 6488 3756 / (+61 4) 04 152 262