Effects Of Long-Term Fertilization On Microbial Biomass Carbon, Nitrogen And Microbial Utilization Ratio Of Carbon Source In Three Typical Soils Of China

By the means of chloroform fumigation method, Biolog-Eco method, and potassium permanganate colorimetry, soil microbial biomass carbon, soil microbial biomass nitrogen, AWCD content, and utilization ratios of 31 carbon sources by soil microbe of long-term located fertilization points in Hunan Qiyang, Henan Zhengzhou, and Jilin Gongzhuling were compared; and analyzed soil microbial biomass carbon, soil microbial biomass nitrogen, organic carbon, total nitrogen, and active organic carbon of red soil in Qiyang at 2008~2009 winter wheat's seedling stage, regreen stage, and mature stage; and after 19 years long-term fertilization in Qiyang, we analyzed the basic physical and chemical properties of red soil, and also analyzed the correlation relationship between the red soil properties and the red soil microbial properties. The major results were summarized as follows:1. Compared with control and inorganic fertilization, after 19 years fertilization at wheat seedling stage total soil microorganism of manure application and inorganic fertilizaton combinated with manure were higher. Manure application and inorganic fertilizaton combinated with manure increased the red soil microbial biomass carbon and microbial biomass nitrogen. To the utilization ratios of carbon sources by red soil microbe, the order of the values were as follow: manure application > control > inorganic fertilization. On the whole, the utilizations that the red soil microbe utilized polymer carbon sources especially tween 40 and tween 80, were at a high level. Compared with control and inorganic fertilization, manure application and inorganic fertilizaton combinated with manure raised the utilization ratios of carbon sources by red soil microbe, and the carbon sources included carbohydrates, polymers, amines, phenols, carboxylic acids. The carbon sources utilization ratios of manure application were similar to that of inorganic fertilizaton combinated with manure.2. Compared with control and inorganic fertilization, after 19 years fertilization at corn maturity stage the drab soil microbial biomass carbon, nitrogen of inorganic fertilizaton combinated with manure and high-power inorganic fertilizaton combinated with manure, were higher. Among the treatments, the utilization ratios of carbon sources by drab soil microbe had a little difference. The utilizations that the drab soil microbe utilized polymer carbon sources, especially tween 40 and tween 80, were higher, and carbohydrate carbon sources next.3. After 19 years fertilization, at corn maturity stage the black soil microbial biomass carbon, nitrogen of inorganic fertilizaton combinated with manure were higher than that of control and inorganic fertilization. The carbon sources utilization ratios of manure application by black soil microbe were higher than that of control and inorganic fertilization. On the whole, to 6 carbon sources utilization ratios by black soil microbe, the utilization ratios of carbohydrates, especially D-mannitol, D-cellobiose and D-xylose, were higher than that of others, and that of phenols lowest.4. The red soil microbial biomass carbon, soil microbial biomass nitrogen, total carbon, total nitrogen, and active organic carbon of wheat regreen stage were all higher than that of seedling stage and maturity stage. Among various treatments there was a little difference between the microbial quotient, the proportion of microbial biomass nitrogen to total nitrogen and the proportion of microbial biomass carbon to microbial biomass nitrogen. Soil microbial biomass carbon, nitrogen and carbon sources utilization ratios of wheat maturity stage were positive related to grain yield.5. The microbial biomass carbon of black soil was higher than that of drab soil, and that of red soil lowest. There was no significant difference between the microbial biomass nitrogen of red soil and drab soil. To the ratios of microbial biomass carbon to microbial biomass nitrogen, the black soil and drab soil were higher than red soil. While to the utilization ratios of amino acids, carbohydrates, phenols, amines, polymers, and carboxylic acids, the black soil were higher than red soil and drab soil.