Studies On Dynamical Changes Of Soil Enzyme Activities And Factors Of Soil Fertility In The Plateau Of Northwest For Heibei Province

The chestnut soil which is the main kind of soil is distributed in the Bashang plateau of northwest Hebei .The problem in agriculture is serious, so the grain self-sufficiency is important to economy and society development. Under existing heat and rain conditions, it is most vital to improve soil fertility so as to solve water and soil nutrition stress and grain yield. The paper studies the dynamical changes of factors of soil fertility and soil enzyme activities and the relationship between them under different farming measures through long-term experiment improving soil fertility, rhizosphere simulating experiment and potato mulching film experiment. The result shows: In the long-term experiment, using organic and inorganic fertilizers increases the yield of wheat, its effect is superior to sole chemical or organic fertilizers. Contrast to CK, N60P45. M22500. M22500N60P45. M22500N120P90 increase production by 65.7%. 43.0%. 79.0%. 91.5% respectively. Using organic and inorganic fertilizer improves the amount of available nutrient (N and P) and total nutrient (N. P. and C). The activities of urease alkaline phospatase . catalase of treatments using organic and inorganic fertilizers is more than using sole chemical or organic fertilizer. Soil temperature of treatment with organic and inorganic fertilizer is more than treatments with sloe chemical or organic fertilizer expect for seeding stages and harvest time. Soil moisture decreases with the amount of fertilizers. Through correlation analysis, the remarkable relationship exists between following the yield of wheat and three kind of enzyme activities ,total N. available N and urease activity, total P. available P and alkaline phospatase, organic C and catalase. In the rhizosphere simulating experiment, the result shows: all yield of fertilizer treatments is more than CK. Contrast to CK, N60P45. M22500. M22500N60P45 increase production by 9.0%. 62.6%. 64.6% respectively. Available N amount in the rhizosphere is more than in the nonrhizosphere expect for the milk stage. Available P in the rhizosphere is more than in nonrhizosphere before the milk stage and it is on the contrary after the milk stage. The urease activity in the rhizosphere is more than in the nonrhizosphere in joint stage, heading stage and milk stage. The phosphatase enzyme activity in the rhizosphere is more than in the nonrhizosphere during the whole growing period. The catalase enzyme activity in rhizosphere is more than in the nonrhizosphere during the whole growing period. Catalase enzyme activity of M22500. M22500N60P45 in the rhizosphere is more than in the nonrhizosphere in jointing stage and heading stage, while it is on the contrary in other stages. Through correlation analysis, the remarkable available relationship exists between the yield of potato and activities and between available N , available and urea enzyme , phosphatase enzyme activity. The result of potato mulching film experiment shows: mulching film plays a much role on improving yield of potato. The yield with film of flat cultivation ridging. ridging with chemical fertilizer ridging with chemical and organic fertilizers is more than the yield without film by 16.34%. 5.36%. 51.37% and 13.60% respectively. During the whole growing period , the amount of available N. P. K of all fertilizers treatments is more than the amount of N. P. K of treatments without fertilizer. Especially ,the amount of those of treatment using organic and inorganic fertilizer is the most in all tr...