Diverse species mix proves worth

CSIRO Agriculture and Food principal research scientist Mark Farrell said the project was looking at species evaluation and demonstrations, across different rainfall zones in SA, Vic and Tas.

Funded by the National Landcare Smart Farms program, the four-year project finishes in 2022.

Dr Farrell said considerations included the movement of soil nutrients up and down the profile, insect responses, as well as monitoring yields of the following "cash crops".

He said similar work had been done overseas but in the Australian environment, moisture could be a limiting factor for cover crops.

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While there was not much data available yet, species evaluation trials at Minnipa showed interesting results when grown in place of a 2019-20 winter crop.

"The mixed species, relative to the individual species, there was a significant different in yield," he said. "It fits with evidence we've seen in the United States that different species exploit different niches and yield more than they would have on their own."

Dr Farrell said many of the species in the mix were also represented individually, such as vetch, canola, tillage radish and peas.

He said the trials compared single species and multi-species cover crops as well as the "business as usual" approach of the grower.