Study On Soil Microbial Quantity, Soil Enzyme Activity And Physicochemical Factor In Various Saline-alkali Soil In Hexi Corridor

11typical plots of the different saline-alkali soils in Hexi Corridor wereselected for the study, the seasonal change of soil microbial quantity and soil enzymeactivity. And the relationship among soil microorganism, soil enzyme activity and soilphysicochemical factors, was studied by variance analysis, simple correlation analysis,stepwise regressive analysis and principal component analysis.The result showed that quantity of bacteria, actinomyces and fungi decreased inthe order: bacteria, actinomyces, fungi. The most quantity of bacteria appeared in thesummer and maximum values of actinomyces and fungi appeared in the autumn. Thepeak of cellulose degradation bacteria, relating to nitrogen-cycle and carbon-cycleappeared in the spring and the autumn. The soil microbial quantity was generally at alow level and at the regularity: primary saline-alkali soil<secondary saline-alkalisoil<farmland soil. There were obvious differences between the plateau swampwetland in Gannan and the saline-alkali soils in Hexi in soil microbial quantity, soilenzyme activity and soil physicochemical, and the saline-alkali soils were morebeneficial for the survival of actinomyces.The study of enzyme activity showed that the data of1and2were high; the dataof farmland soil10and11were relatively high; others were low. Though there was noobvious regularity in the seasonal dynamics of soil enzyme activity, the threephosphatase activity and catalase activity were lowest in the winter and the peaks ofurease activity and cellulase activity were in the winter.The relationship among soil microbial quantity, enzyme activity and soilphysicochemical, resulting from simple correlation analysis, was caused by thepopulation of fungi, actinomycetes, urease activity, phosphatase activity, pH andSO₄^2-et al. The ideal regression equations about soil microbial quantity, soil enzymeactivity and soil physicochemical, were obtained by using stepwise regressionmethod.Principal component analysis among soil microbial quantity, enzyme activitiesand soil physicochemical showed that pH, Na⁺, fungi urease activity and phosphataseactivitywere should be considered as important factors to soil fertility characteristics.The results also indicated that soil nitrogen-cycle and phosphorus-cycle influenced thefertility of saline-alkali soil in Hexi Corridor.The study of the relationship among microbial population, enzyme activity andsoil physicochemical factors in saline-alkali soils in Hexi is helpful to reveal therelationship among various ecological factors in the soils.and provide basic and scientific evidences for the improvement of saline-alkali soils in this area.