Abstract:

This article sub-elected seven sizes of soil aggregate under ridge tillage, conventional tillage and winter paddy field. Soil microbial biomass nitrogen and urease activity of soil aggregates were measured under the three tillage practices. The author tried to find the soil aggregates and soil urease activity of the relationship between tillage or soil aggregates in the urease activity and microbial biomass N correlation. The results showed that: the distribution of microbial biomass was mainly affected by soil structure, and not significant by tillages. The effect of different tillage methods on soil aggregates in the urease activity were obvious; urease activity and microbial biomass were not significantly correlated, indicating that the main source of urease in purple paddy soil might not be microorganisms.