Towards sustainable consumption of legumes: How origin, processing and transport affect the environmental impact of pulses

Pulses are important components in sustainable diets and cropping systems. This study evaluated the environmental impact of cultivation of five Swedish pulses (yellow peas, grey peas, faba beans, common beans and lentils) in a life-cycle perspective. The impact of selected Swedish pulses (conventional or organic) was then compared with that of imported pulses in Sweden, including contributions from processing, packaging and transport. The influence of origin and transportation mode and differences between home cooking and canned pulses (Tetra Recart) were considered.

The impact of cultivation differed considerably between the Swedish pulses, ranging between 1.6–3.3 MJ, 0.18–0.44 kg CO₂e and 3.1–5.9 m² land use per kg dry product. In general, pulses with higher yield had lower cultivation impact. However, intercropping pulses and cereals showed potential to reduce environmental pressures, despite low per-hectare yield of the pulse crop. When processing, packaging and transport were included, the variation in impact was even greater, illustrating the importance of including post-farm activities in the assessment when comparing pulses. Emissions of greenhouse gases per kg cooked product ranged from 0.1 kg CO₂e for Swedish pulses purchased dry to 0.8 kg CO₂e for canned beans.

Long transport distances contributed considerably to energy use and climate impact, particularly when the pulses were processed and packaged far from the final destination, due to high moisture content of the product. Origin affected also biodiversity impact, since the risk of species losses differs widely between ecoregions. Pesticide use is reported to be high in many countries, and residues are commonly found in many pulses. However, lack of data prevented comparisons of ecotoxicity or pesticide use for different imported pulses. The important role of origin and post-farm activities, in particular transport, for the environmental impact of pulses calls for increasing awareness and action amongst purchasers, food industries, and consumers to achieve more sustainable sourcing of pulses.