Productivity Advantage of Crop–Perennial Pasture Intercropping in Southeastern Australia

Abstract

Annual‐based pasture and/ annual crops are now commonly the basis of farming practices in higher rainfall regions of southern Australia. For environmental reasons, farming systems used in higher rainfall regions should ideally target use of more perennials in the landscape without impacting farm productivity or profitability. Intercropping may provide the opportunity to achieve this, where the pasture component is a perennial species. The perennial pasture species lucerne (Aurora Medicago sativa L.) and chicory (Puna Cichorium intybus L.) were established and maintained for three seasons with annually sown crop species (Whistler wheat [Triticum aestivum L], Wonga lupin [Lupinus angustifolius L] and Sapphire canola [Brassica napus L.]) in a double skip row arrangement. These intercrops were compared for production and productivity with individual crops and pastures grown as monoculture stands. Grain crop yields were reduced when grown in intercrop with lucerne and chicory. Yield reductions ranged from 0 to 46% for wheat, 45 to 74% for lupin, and 8 to 83% for canola. Pasture dry matter was also reduced when intercropped, with reductions ranging from 0 to 78% for lucerne and 19 to 78% for chicory. Despite reductions in crop and pasture production, the land equivalent ratio (LER) ranged from 0.42 to 1.78, with most intercrop combinations overyielding. Chicory was well adapted as an intercrop species, with chicory intercrops overyielding more frequently than lucerne intercrops. In addition, the overyielding of lupin and canola intercrops demonstrates the potential to expand intercropping to include break crops, creating a more flexible system suited to southeastern Australia.