氮素和水是生态农业中最常见,最重要的限制因素。牧草,特别是豆科牧草在生态农业系统中的作用越来越重要。如何向豆科牧草提供更多可供吸收的氮素,同时保持土壤中有充足的氮素储备,保持豆科牧草优质高产,是解决当前草地畜牧业快速发展中蛋白质饲料不足问题的重要措施。把豆科牧 Nitrogen and water are the most common and important constraints in eco-agriculture. Herbivores, especially legumes, play an increasingly important role in eco-agricultural systems. It is an important measure to solve the problem of insufficient protein feed in the rapid development of pasture husbandry in grassland so as to provide more available nitrogen to the leguminous pasture while maintaining sufficient nitrogen reserves in the soil and maintaining high quality and high yield of leguminous pasture. The legume animal husbandry