摘要
研究了紫花苜蓿改善土壤的物理性状、水文效益、渗透速度、茎叶截雨量、根系密度、生物量和经济效益。结果表明：紫花苜蓿可以减小土壤容重、增加土壤孔隙度、提高土壤贮水量，茎叶吸水率达到自身重量的５２．８９％，根系的７８．２６％集中分布于０～３０ｃｍ土层内，根系密度４２．７条／１００ｃｍ２，生物量１３．５６６ｔ／ｈｍ２，年产干草１７．６８７ｔ／ｈｍ２，水土保持效益和经济效益显著。
The effects of alfalfa were tested on the physical properties improvement of soil, the hydrological benefit, the infiltration rate, the interception of rainfall by stem and leaves, the root density, the dry matter production and economical benefit. The results showed that alfalfa could decrease the soil unit weight increase the porosity of soil and enhance the water-holding capacity of soil. The water absorption of stem and leave amounted to 52.89% of its own weight, The water absorption of roots accounted for 78.26% of it own weight, the root system was mainly distributed in soil layer from 0 cm to 30 cm. The density of roots was 42 7 roots 100 cm 2, the biomass was 13 566 t/hm 2, 17 687 t/hm 2 dry grass was producted soil protect effect and economic effect, were remarkable. Therefore, alfalfa is a excellent plant species for soil and water conserva tion.
