Study On Denitrification Potential Of Calcareous Soils With Different Development Degrees

Typical calcareous soil?Huanjiang,Guangxi?as the research object,the soil column culture acetylene inhibition method is adopted to set up the denitrification potential of calcareous soil column experiment training system,compare the denitrification potential of calcareous soil in situ soil column,and explores the human C,N disturbance condition,the response characteristics of the lime soil denitrification potential.The main results are as follows:1.A culture experiment system suitable for Denitrification Potential?DP?of calcaric soil was established.The key parameters were:the culture time was 24h,the culture temperature was 25?,the soil saturated water capacity and unit weight were 1.05g/cm³.Under these conditions,the overall precision of soil DP can reach 29%.In the culture parameters,the soil DP has a strong response to the bulk density of the soil column,and the relationship betweenincrease of time.The linear regression equation between soil column culture time and denitrification potential is y=9.7367x-57.051?R²=0.996?,showing a positive correlation.The potential of denitrification increases exponentially with the increase of temperature.The regression equation between soil column culture temperature and denitrification potential isincrease of soil water holding capacity.The regression equation between soil moisture?WHC?2.Emission intensity of different soil denitrification potentials:in the summer soil column,the maximum DP was 22.0ug·h^-1·kg^-1 in black calcined soil,and the minimum DPsoil<brown calcined soil<corn upland soil<black calcined soil.In the winter soil column,the maximum DP was 17.5ug·h^-1·kg^-1 in brown lime soil,and the minimum DP was0.98ug·h^-1·kg^-1 in red soil.The correlation of different soil DP was that red soil<paddy soil<maize drought-land soil<black lime soil<brown lime soil.3.Interference experiments with the artificial addition of exogenous glucose and nitrate nitrogen showed that although the average value of soil DP increased with the addition of exogenous glucose and NO₃^-,the interference of C and N had no significant effect on soil DP.