It is becoming clear that the productivity gains required for Australian agriculture to remain competitive, and contribute to the increasing global demand for food, fibre and energy, will need not only small incremental gains in productivity, but may also require transformational changes to existing production systems. The challenge for farmers and researchers is to devise new cropping systems or ‘break through innovations’ that sustainably and substantially increase production with minimal risk. Australia’s northern grains growing region has a predominantly summer rainfall pattern that imposes constraints on existing cropping systems, but also provides opportunities to maximise the use of available resources like rainfall, sunshine, temperature, and soil nutrients. Opportunistically sowing legumes into standing wide row summer cereal crops in response to late season rainfall could sustainably increase production and farm profitability and manage climate risk in controlled traffic systems across the Northern Grains Region.
This paper investigates the production of maize-mungbean relay crops compared to convention sole crops. Five maize-mungbean relay crops were sown over 3 years at Gatton, Queensland to investigate the influence of mungbean sowing time relative to maize phenological stage and row spacing. Grain yields for maize cultivar “34N43” and mungbean cultivar “Crystal” ranged from 3.9 to 9.6 and 0.4 to 2.4 t/ha, respectively.
Relative sowing time had the greatest influence on mungbean yield and overall production, but did not influence maize yield. Grain yields of mungbeans sown into maize between late grain fill and physiological maturity were equal to or greater than sole crops and increased overall land productivity by up to 2.4 fold.
There is a need to further test relay cropping technologies on-farm in multiple environments across the Northern Grains region and to identify potential novel multi-crop arrangements.