New Insights into the Yields of Underexploited Grain Legume Species

Protein-rich grain legumes are grown for both human food and animal feed, and their multiple benefits to the environment. Pea (Pisum sativum) is the most widely cultivated grain legume in Europe. In the world, several field experiments have compared the yields of a broad range of grain legumes in contrasting environments, but these experiments have never been synthesized. We address two questions: 1) What is the yield levels of pea compared to other grain legume species in Europe? 2) Which grain legume species with good yield performances in North America and Oceania are candidates for future European experiments? We conducted a statistical analysis of five variables – grain yield, total aerial biomass, grain crude protein, grain gross energy, grain nitrogen content – comparing 22 grain legume species with pea, based on experimental data extracted from 61 peer-reviewed articles and nutritional data. We identify soybean (Glycine max), narrowleaf lupin (Lupinus angustifolius), and faba bean (Vicia faba), as alternative grain legumes to pea in Europe. Grain legume species grown in North America do not outperform pea for most of the criteria. In Oceania, faba bean has significantly higher yield than pea, whereas several species do not differ significantly from pea. Based on data collected in North America and Oceania, we suggest assessing the relative productivities of several vetches and lupins (Lathyrus, Lupinus, and Vicia species) in European experiments. Our findings reveal new insights into the yields of as yet underexploited grain legume species for potential future use in Europe.