The Simulation Study Of The Acidification Of The Black Soil Nature Of Respiration

Sulfuric acid solution to adjust the black soil of pH, respectively transferred4.5,5.0,5.5,6.0,6.5,7.0. Monitoring the dynamic changes of the50d within the soil carbon dioxide emissions rate, the carbon dioxide accumulated emissions. Revealed the number of soil microbial acidification, enzyme activity, microbial biomass carbon, dissolved organic carbon, respiratory quotient, soil properties, soil respiration, the main conclusions are as follows:(1)Acidity of soil respiration rate had a major impact, the different acidity of soil CO2emission rate of the size of the order pH4.5<pH5-<pH5.5and<pH6<pH6.5<pH7, When the pH between6-7, soil microbial activity is exuberant, the reunion of the enhanced role of good soil aeration increased rate of CO2emissions; when the pH dropped to5.5-6, soil microbial activity is weakening, but the agglomeration continues lead to enhanced ventilation increased CO2emission rate is still increased, but the growth rate decreases; slow decline in pH in the5-5.5, soil microbial activity continue to weaken, the rate of CO2emissions; when the acidity reduced to below5, the soil microbial activity has been seriously hampered, activity decreased to quickly lower the rate of CO2emissions.(2) Summer soil respiration is greater than in autumn, which may be less affected by the biological activity with the fall of CO2emission and pH decreased, better soil aeration, reduce CO2emission differences between the different pH. pH in the4.5-5.0, summer soil respiratory quotient is less than the fall, this is due to the low pH, better soil aeration. With the increase of the pH of the summer soil respiratory quotient greater than the fall, this may be due to high summer temperatures, strong microbial activity.(3) Soil acidification, the correlation between the summer and autumn, the cumulative number of microorganisms in the soil, soil enzyme activity and soil CO2emission slightly different, but the acidity affect the bacteria in the soil, put the line of the number of bacteria and mold, thus affecting the soil enzyme activity in the soil carbon cycle, and thus soil acidification and inhibition of soil respiration to a certain extent.(4) When the acidity, respectively, between4.5-5.0,5.0-5.5, soil cellulase, invertase activity reached the highest value, indicating that soil acidification to a certain range, soil cellulase, invertase activity was excited. The pH value of6.0-6.5, soil peroxide highest CAT activity, the mineralization of organic carbon, soil respiration is also strong. When the pH value of5.0-5.5, soil urease activity, but the soil respiration but was suppressed. Amylase activity in the soil pH value of4.5-5.0, with the rise of pH and reduce the accumulation of CO2emission increase.(5) Acidification affected soil microbial utilization of organic carbon, thus inhibiting the respiration of the soil. Compared with pH=7processing, the content of soluble organic carbon content was significantly less than the soil is neutral. Soil acidification has led to differences in soil microbial biomass and activity, thereby affecting soil respiration, MBC content in the soil and higher DOC concentrations in soil respiration is the stronger.(6) Soil acidification, with the increase of soil organic matter content, soil respiration increase. Lower acidification, soil cation exchange capacity decreased, the enhanced role of soil aggregation, soil aeration changed for the better, soil respiration strong.