Penny Roberts1, Michael Moodie2, Nigel Wilhelm3
1 SARDI, 155 Main North Road, Clare, SA, 5453, email@example.com
2 Frontier Farming Systems, 7B Byrne Court, Mildura, Victoria, 3500
3 SARDI, GPO Box 1671, Adelaide, SA, 5001
Intercropping has the potential to provide production and sustainability benefits in low rainfall dryland cropping systems. With a small number of growers adopting break crop intercropping in the SA Mallee environment there is demonstrated potential for this practice to be adopted more widely.
Two years of field based research was undertaken at Waikerie in the South Australian Mallee to investigate break crop species mixes suited to this environment. The trials conducted in 2016 and 2017 focused on pulse/canola intercrops and were compared to monoculture stands of the intercrop components. Grain yield, biomass and soil nitrogen were measured to determine the relative benefit of the different intercrops.
There was over-yielding in all intercrop combinations, demonstrating that increases in productivity of 12 to 80% are achievable in this Mallee environment. An economic analysis demonstrated that most intercrops combinations had similar or higher gross margins than the monoculture crops in both years, with the benefits greater in seasons with more favourable growing season conditions.
This work demonstrates that intercropping has the potential to increase both productivity and financial returns in low rainfall cropping regions. In addition, the adoption of this practice could lead to ancillary benefits such as increasing groundcover on erosion prone soils.