Abstract: A greenhouse pot experiment was conducted to study the effects of wheat root activity and fertilization mode on the microbial amount and urease and phosphatase activities in black soil. Under the conditions without wheat planting, the amounts of soil fungi  increased by 47.0%  in treatment NPK, and the activities of soil urease and phosphatase under fertilization increased by 17.2%-32.7%, and 21.2%-25.9%, respectively. With wheat planting, the amount of soil microbes and the activities of soil urease and phosphatase in treatment CK increased by 39.0%, 302%, and 38.5%, respectively, due to the root activity of wheat. The coupling of fertilization and wheat root activity increased soil microbial amount and soil urease and phosphatase activities significantly, with the increment being 3.3%-31.4%, 59.0%-168%, and 15.2%-26.7%, respectively. Soil phosphatase activity and the amounts of soil bacteria and fungi had significant positive correlations with the above- and belowground biomass of wheat.

Key words: Dissolved organic matter, Soil, Organic pollutant, Environmental behaviors