Should crop sequences in Western Australia include more lupins?

Abstract

Context Reducing greenhouse gas emissions is an increasing priority for Australian grain producers. Could substituting lupins for canola, as a rotational break crop, enable farmers to reduce their emissions by less use of nitrogenous fertilisers? Aim This study aims to identify if replacing canola with lupins in rotations at a range of locations in Western Australia’s grainbelt is environmentally and economically attractive. Methods Bio-economic simulation modelling is used to examine the gross margins and emissions associated with replacement of canola by lupins at 14 locations in the grainbelt of Western Australia in various land use sequences. Key results Replacing canola with lupins unambiguously leads to reduced emissions in crop sequences at all locations considered. However, the higher gross margins from canola production cause lupins to only be a preferred break crop option at 4 of the 14 locations. Even with various plausible incentives to favour lupins, they remain economically unattractive at most locations other than those where lupins are well adapted to the environment. Conclusions Lupins’ current lack of commercial attractiveness for farmers limits its role in emissions reduction in the region’s farming systems. Implications The profitability of lupins needs to increase if lupins are to be widely readopted. This requires developing higher yielding lupin varieties, grain quality improvements, and policy changes to reward lower emission cereals. However, this study shows these changes, apart from yield improvement, are unlikely in the short term. At locations with suitable soils alternative pulse crops may offer higher gross margins whilst delivering emission reductions.