The Mineralization Characteristics Of Soil Orgnic Carbon Under Different Nitrogen And Phosphous Fertilizers

Effect of different fertilizers on the soil organic matter mineralization is studied. As known to us, the biological activity of soil organic matter directly reflects the level of soil quality and production capacity. Gradually, high attention is paid to soil microbial biomass as a sensitive quality standard nowadays. This subject is studied under different water contents and nitrogen and phosphorus fertilizers in the soil to find how the soil organic carbon mineralization rate and microbial biomass C and N dynamic changes will be affected. The main results were as follows:1. Influence of changing nitrogen fertilizer application rate on microbial biomass carbon was not significant, While that of changing phosphate fertilizer application rate on microbial biomass carbon was significant.2. Different nitrogen fertilizer levels affect soil nitrate more significantly, Changes of nitrate nitrogen is in the range of 32.27~189.95 mg/kg. Soil water moisture content has a centain extent effect on ammonium.The minimum value of ammonium is 2.22 mg/kg, the highest value reached 21.72 mg/kg. Changes of nitrate nitrogen is in the range of 38.29 ~ 104.26 mg/kg. Soil moisture content has not an obvious effect on nitrate nitrogen.3. Soil moisture affect the microbial biomass by affecting microbial life when other related conditions were in a certain circumstance. Fluvo-aquic soil microbial life activities require moderate water content which is about 70% of soil water holding capacity.4. The order of accumulative mineralization value which is under three soil moisture content is 70%WHC>100%WHC>40%WHC. Under each water content treatment , highest value of soil organic carbon cumulative mineralization is not synchronized emergence.5. Relationship between microbial biomass carbon and soil organic carbon is positive significally correlation.