It’s not exactly breaking news that the human population is exploding, and demand for food along with it. One of the major limitations to meet that demand will likely be water availability; as groundwater supplies dwindle, droughts will only become more common. Water shortage will no doubt affect the yield of every crop humans cultivate, but legumes are one of the most agriculturally and economically important crops in the world. (Second only to cereal for food security, global legume production is valued at roughly $31 billion annually.) The plant family encompasses peas, beans, peanuts, lentils—any pod-encapsulated seed—and grows in almost every climate region.
A team of researchers sought to find out how drought will affect the many varied species of legumes grown around the world. To determine how legume species, drought timing, regional climate, and soil texture influence crop yield, the study authors conducted a meta-analysis of 110 studies, carried out between 1980 and 2014, that looked at the drought-time yields of individual species of legumes.
The team reports in PLoS One that both the species of legume and the stage of the plant’s life cycle influenced the impact that drought had on crop yield. For example, yield was generally lower when droughts occurred during the plant's reproductive stage. The study also found that lentils, peanuts, and pigeon peas held up well to drought conditions. The common bean, on the other hand, was highly sensitive to drought.
Because the region where the plants grew had less of an effect on drought-time yields than the species of legume, the researchers write, the creation of drought-resistant legumes could be a widely applicable approach to combating drought-induced crop losses.