Northern farming systems – Spring Ridge site report, 2015–2020

Abstract

Key findings • The lower crop intensity system resulted in a significantly lower overall system grain/ lint productivity (t/ha) compared with the baseline (−4.8 t/ha) however, it performed very well in the economic evaluation (+$56/ha). • Winter pulse crop choice (chickpea versus faba bean versus field pea) had little effect on the long-term soil nitrate dynamics. • The higher legume system required less nitrogen (N) fertiliser inputs (114 kg N/ha vs 137 kg N/ha) and exported more N (428 kg N/ha vs 347 kg N/ha), while maintaining higher soil nitrate (+80 kg N/ha) than the baseline system at harvest 2020. • Potassium (K) export in grain ranged from 34 kg/ha to 73 kg/ha between all systems. The highest removal was seen in the higher legume system. This K removal is concerning, particularly in the long-term, considering that currently there is no additional K applied to offset this removal. • Short fallows (4–8 months) out of wheat gave the highest fallow efficiencies (20–53%) compared with the two short fallows (4–8 months) following pulse crops (0–17%) and the longer fallows after cereals (10–34 months) (12–22%).