Effect of improving soil fertility by organic materials on the composition, C, N distribution and activity of microaggregates

Dou Sen et al

soil fertility, organic materials, microaggregates distribution, activity

The effects of improving soil fertility by organic materials(ISFOM) on the composition, C, N distribution and activity of microaggregates were studied with field experiments in Brown earth and Black soil. The method used in this paper for preparating microaggregates was also evaluated. The results were summarized as follows; 1, the dominant and secondary dominant partical sizes in the soils were 10-50 and 50-250|im, respectively. The C, Ndistribution in various partical sizes of microaggregates were generally in follow sequence: 10- 50>50 - 250^0- 5> 5-10|am fractions; 2, the carbon activity(CA)and nitrogen activity(NA)were increased with the increase of the partical size of microaggregates; 3, the content of 50-250|am partical size in microaggregates composition and the CA, NA of various sizes of microaggregates were basically increased after EJFOM; 4, the sedimentation siphonage method for preparation of microaggre-gates is available before a new method found.