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

Abstract The European Union is currently not self-sufficient in soybean and maize. Here, we examine the potential for maize-soybean intercropping to improve the European Union’s soybean self-sufficiency while minimizing trade-offs with the production of maize and other crops. Assuming a return every four years, intercropping on 6.3, 13.1, and 20.1 Mha produces 9.1 (28.8), 18.2 (63.7), and 27.2 (99.0) Mt of soybean (maize), respectively, thus achieving 25% (34%), 50% (75%), and 75% (116%) self-sufficiency levels, respectively. Reaching similar co-productions with sole crops require an additional 11.1, 24.7, and 36.5 Mha, corresponding to land savings of 20– 21% with intercrops. Meeting 100% of European soybean demand would require growing intercropping on more than 25% of European cropland (25 Mha) every year. These estimates held under a large range of nitrogen inputs and temporal overlaps between crop species, provided that soybean production from 1 hectare of intercropping exceeded that from 0.5 ha of sole soybean. Expected land-savings estimates suggest that geographic variation in crop yields should be considered to estimate land-use efficiency of intercrops. Our results underline that intercropping is an effective strategy to simultaneously improve European soybean production, satisfy maize needs, and save cultivated lands.