Effects On Functional Diversity Of Soil Microbial Communities Of Abandoned-field By Sowing Legume Species

Soil microbial plays a significant role in ecosystem which is the main index to evaluate soil microbial diversity is the important one of globle diversity. Exploring the effect of species restoration approaches on one of global soil microbial community can provide scientific bases for systemic and impersonal assessments of abandoned-field restoration approaches and the restoration practice of degraded ecosystems.The effects of sowing legume species (Medicago saliva, Melilotus suaveolen, Astragalus huangheensis) on functional diversity of soil microbial communities were studied in the abandoned-field succession of Loess Plateau. In the study, physical and chemical properties, soil microbial biomass, soil microbial community diversity and bacteria community variety were measured after sowing legume species in abandoned-field. Through the above measurements, soil fertility and soil microbial diversity of the ecosystems were researched. Results showed that:(1) After sowing legume species in abandoned-field, the result showed that there was low-lying soil water content, bulk density, pH (except for Melilotus suaveolen), higher soil organic carbon and total nitrogen. (2) There also was higher soil microbial biomass carbon (except for Melilotus suaveolen) and soil microbial biomass/organic carbon in the soil. Soil under Medicago sativa-adding had the highest soil organic carbon, microbial biomass and total nitrogen in all treatments. (3) In BIOLOG, it also indicated that the average well color development (AWCD) in BIOLOG assays was increased; the sole carbon source metabolic ability of soil microbial communities and the microbial metabolic diversity indices (the richness and diversity indices) were significantly higher; the number and structure of soil bacteria community was changed. Therefore, sowing legume species in abandoned-field could change the structure of bacteria community and increase the functional diversity of soil microbial communities and also influence the variety of the soil fertility and quality.