Effect of No-Tillage on Soil Microbial Biomass Carbon in Arid Area of Yellow River Under Different Rotation Patterns

摘要

Based on effects of no-tillage on the vertical distributions and dynamic change of soil microbial biomass carbon, rotation effect, and crop yield in arid area of Yellow River (treatments were conducted in 2005,and taking sample was between 2006 and 2008), change trend of soil microbial biomass carbon of five different treatments under three rotation patterns of oat, corn and soybean was analyzed. The results showed: (1) The change of soil microbial biomass carbon was diauxie curve in growing period. The soil microbial biomass carbon content of different treatments under three rotation patterns was: high stubble mulching>low stubble mulching>high stubble>low stubble, and the first peak values of two stubble mulching treatments was earlier than other treatments, which indicated that improvement of soil temperature and water effect of straw mulching speeded up the decomposition of stubble and straw and enhanced the soil microbial activity.(2)The soil microbial biomass carbon content at different depth was:0-10cm>10-20cm>20-30cm.There was significant difference in soil microbial biomass carbon at the depth of soil 0-10cm of different treatments(p<0.01),and significant difference at the depth of 10-20cm,especially the straw mulching(p<0.05).Because biological indicator of soil quality could be evaluated by soil microbial biomass carbon, executing conservation tillage in arid area of Yellow River of no-tillage with straw mulching could enhance the soil microbial activity and improve the soil quality.