Spatial Heterogeneity Effects In Micro-scale Aggregates On Acid Soil Autotrophic Nitrification

Soil aggregates is an important part of soil, at home and abroad to study the relationship between soil organic-inorganic composite soil aggregates a lot of research that material foundation and an important mechanism of organic-inorganic composite soil water stable aggregates formed. Soil aggregates, especially water-stable aggregates have a huge impact in the agricultural and soil erosion. Structure and its influencing factors of stability and water stability of soil aggregates as an important aspect of the study of soil science and soil erosion.Soil nitrification of ammonium nitrogen is converted to nitrate and nitrite nitrogen by biological oxidation process, the major part of the nitrogen cycle, but also one of the potential avenues of nitrogen loss. Therefore, the study of this system Jiangxi red soil aggregates nature of nitrification. Red soil by wet sieving method to filter out the>1.0mm,1.0-0.5mm,0.5-0.25mm,0.25-0.53mm, and<0.053mm5particle size of the aggregates, and filter out the particle size of the aggregatesnitrification culture, different reunion nitrification characteristics in vivo, and the use of kinetic equation simulation aggregates internal nitrification and nitrification potential. The solk water stable aggregates of different diameter(>1.0.5～1,0.25～0.5,0.053～0.25,<0.053mm) were gained and determined by wetting sieving method in jianxi red soil.The result indicated that red soil pH relatively low(4.83-5.36). The pH value in the distribution of the different particle fractions in the soil as the particle size decreases, its pH value first increases, then decreases, and finally a tendency to increase.Red soil acidity is determined by exchangeable Al3+. Exchangeable H+content is extremely low, accounting for5%to8%of the acid content of the exchange. Exchangeable acid content of the aggregate size with the particle size decreases, exchangeable acidity showing reduced-increasing-decreasing tendency.Studies have shown that the nature of the different size aggregates red soil nutrient content.In these red soils,soil organic C、N accumulated in aggregates of fractions>0.25mm, which shows that microbial biomass C、N in aggregate increased with the increase in particle size, especially soil organic C、N. As to>0.25mm water-stable aggregate, the content of their organic C、N and microbial biomass C、N increased with the enlarging of diameter of aggregate. Electrochemical Properties of red soil aggregates of different particle size,the specific surface area gradually increases with decreasing particle size of the aggregates (1～0.053mm); surface charge density of the surface electric field, and specific surface area has the same trend.<0.053aggregates trend of the type of the specific surface area of the particle diameter, a surface area of41.98m2/g; surface charge density of-2.2*10-2C/m2; surface farm-3.11*107J/MC.Studies have shown that different size aggregates red soil nitrification,different aggregate size changes in pH during the28days of culture, as the culture of the increase in number of days, pH showing the trend first and then decreased. Different size aggregates nitrate content increased with the culture of the increase in the number of days. Different size aggregates of ammonium nitrogen trend, as the culture of the increase in number of days, the ammonium nitrogen substantially increased and then decreased trend.Aggregates internal nitrification characteristics of>1.0mm,1.0-0.5mm,0.5-0.25mm,0.25-0.53mm, and <0.053mm5particle size of the aggregates internal nitrification process for the first-order kineticssimulation.