Winter legume rotation improves rice yield (#journal)

Winter legumes in rice crop rotations reduces nitrogen loss, and improves rice yield and soil nitrogen supply

Intensive irrigated rice-wheat crop systems have caused serious soil depletion and nitrogen loss in  China. A possible solution is the incorporation of legumes in rice, but little is known on the impact of legumes on rotation, soil fertility, and nitrogen loss. This study considered the effect of five rice-based rotations on soil nitrogen, rice yield, and runoff loss. Results show that replacing 9.5–21.4 % of nitrogen fertilizer by rape, vetch or bean residues maintained rice yields, and using legumes as a winter crop in rice-bean and rice-vetch combinations increased rice grain yield 5 % while decreasing nitrogen runoff 30–60 %.