Influences of Fertilizer,Irrigation Fire on Community Characteristics and Soil Nutrient in Desert Steppe

The experiment investigated influences of fertilizer,irrigation and fire on community characteristics and soil nutrient.The results indicated that fertilization increased the content of available N significantly(P0.05),reduced the pH value slightly,no significantly influences of soil total nutrient;Irrigation reduced the content of available N,increased the pH value,no significantly influences on soil total nutrient;Fire increased pH value,soil total nutrient and available nutrient had increased trend,reduced the content of organic matter;Fertilizer,irrigation and fire reduced the cluster number(P0.05)and coverage of communities;Fertilizer and irrigation increased the communities height(P0.05),fire reduced the communities height but no significantly differences;Fertilizer and irrigation increased the above-biomass(P0.05),fire reduced the above-biomass but no significantly differences.