Dynamics of invertase activity of black soil treated by a long-term located fertilization and its influence.

The dynamics of the invertase activity in the soil w ith a long term located fertilization during the crop growi ng season were studied. The results show that a significant difference is found in soil invertase acti vity of black soil treated by high organic fertilizer in crop growing seas on, while t here is no significant difference in that treated by low organic fertilize r. The invertase activity is gradually increased in the early crop growing stage, and does not changed in the late plant growing season when the soil is treat ed with chemical fertilizer or without fertilizer. The invertase activity in the soil with organic manure treatment is higher than that with chemical fertilize r treatment, without fertilizer treatment, and with low organic fertilizer treatment , it is conserved over 56mg/g soil ·d and changes little in different seasons. The organic mat ter can protect the soil invertase significantly. Significant and positive signi ficant correlations are found between soil invertase activity and soi l biologica l, physical and chemical properties of partial soil in without and wit h low org anic fertilizer treatment and mostly soil factors, N, P and K contents of plants.