High potential contribution of intercropping to soybean and maize self-sufficiency in Europe

This study examines whether maize-soybean intercropping could improve the European Union's soybean self-sufficiency while minimizing trade-offs with maize and other crops production. Assuming a four-year return, intercropping on 6.3, 13.1, and 20.1 Mha could produce 9.1 (28.8), 18.2 (63.7), and 27.2 (99.0) Mt of soybean (maize), achieving 25% (34%), 50% (75%), and 75% (116%) self-sufficiency. Reaching similar co-productions with sole crops require an additional 11.1, 24.7, and 36.5 Mha, implying 20-21% land savings with intercrops. Full soybean self-sufficiency could require more than 25 Mha of intercrops (25% of European cropland) annually. These estimates held under a large range of nitrogen inputs and temporal overlaps between crop species, provided 1 hectare of intercropping produced more soybean than 0.5 hectare of sole soybean. Geographic variation in sole crop yields should therefore be considered when assessing intercrops land-use efficiency. Our results highlight intercropping as a strategy to simultaneously improve European soybean production, satisfy maize needs, and save lands.