Effects of adding poplar and willow branches on organic carbon, moisture and microbial activities of sandy soil

Taking sandy soil of Yinchuang, Ningxia Hui Autonomous Region as research object, the organic carbon content, moisture, microbial quantity and enzyme activities of soils, that were treated with different methods, including without any treatment(A, control), adding poplar woody chips(B), adding poplar woody chips+covering with willow branches(C) and covering with mixed woody chips of poplar and willow(D), were tested in this study. The results indicated that, treatments of B, C and D could significantly increase soil organic carbon content, moisture and microbial quantity(bacteria, fungi and actinomyces), especially the quantity of bacteria and actinomyces. The activities of urease and catalase were largely improved by treatment B and C. However, the urease activity of treatment D was lower than that of control, and the catalase activity treatment D had no significant difference with control(P0.05). The results of correlation analysis indicated that, there were significant correlations among soil organic carbon content, moisture, bacterial quantity, fungi quantity, actinomyces quantity, urease activity and catalase activity(P0.05). So adding organic matters can significantly improve sandy soil and increase soil bacterial activities.