Response of the black soil enzyme activities to different fertilizer applications.

On the base of field experimentation and sampling,the status and diversity of enzyme activities relevant to cycle of C,N,P in the black soil from the Hailun Agroecological Experimental Station were tested.The results showed that soil enzyme acted as a biological catalyst in soil cycle,and its variation could be used as an indicator for soil fertility.The application of different organic and inorganic fertilizers significantly affected the soil enzyme activities under the field conditions.N fertilizer could increase invertase and protease activities,and organic fertilizer increased the organic contents and urease activity significantly.Urease activities were significantly correlated with different fertilizer applications and crops,and extremely significantly correlated with the interaction among crops and fertilizer application,which showed that urease activities could be used as the characteristic of fertilizer level under different crops and fertilizer applications.The activities of invertase,protease,phosphatase and urease under waste land were less than those of the continuous tillage,which indicated that catalase was less sensitive to tillage than the other four kinds of enzyme.