The Vertical Distribution Pattern of Alfalfa's (Medicago sativa L.) Root Biomass
In order to provide the evidences for further research of alfalfa (Medicago sativa L. ) , the substantial studies of alfalfa root biomass in China, the United States and Canada were summarized. The vertical distribution pattern of alfalfa root biomass and its dominant factors in different natural regions were discussed. Factors included the depth of soil layer, underground water level, soil properties, fertilization, irrigation, cutting, mixture sowing, cultivar, and growth period. The distribution of alfalfa root biomass in topsoil was increased as the depth of soil layer lessened and the level of underground water increased, or soil conditions became worse. Fertilization, especially phosphate fertilizer increased the distribution in submerged soil. Different irrigation amount, frequency and pattern had the complex effect on vertical distribution of alfalfa root biomass. Less single irrigation amounts and higher irrigation frequency increased the distribution of alfalfa root biomass in topsoil. Higher cutting frequency decreased the distribution in submerged soil. Mixture sowing with graminous plants increased the distribution of alfalfa root biomass in topsoil. Alfalfa cultivars have different vertical distribution patterns of root biomass. The soil layer of vertical distribution became deeper as the plants grew. Alfalfa root biomass decreased exponentially with soil depth increasing. Under normal conditions, the distribution ratios of alfalfa root biomass in the 0~30 cm depth were about 60% to 90%, and in the 0~60 cm depth were about 65% to 95%
Medicago sativa L.RootRoot BiomassVertical distributionVertical distribution pattern
NETL
NSTL
万方数据
维普
