玉米地土壤反硝化速率与N<sub>2</sub>O排放通量的动态变化

玉米地土壤反硝化速率与N₂O排放通量的动态变化

摘要: 应用乙炔抑制原状土柱培育法测定了4种施肥处理的玉米地N素反硝化损失速率和氧化亚氮(N₂O)排放通量，并分析了它们与土壤湿度、土壤温度以及硝态氮(NO^-₃-N)含量之间的关系，计算了因反硝化和N₂O排放造成的N肥损失率。结果表明，玉米生育期内土壤N素的反硝化损失量为0.67～3.85kg/hm²，N肥的反硝化损失率为0.5%～1.5%；土壤N2O排放总量为0.55～1.42kg/hm²，N肥的N₂O排放系数为0.2%～0.5%。

Abstract: Denitrification rates and N₂O fluxes are measured by using the acetylene inhibition method on intact soil cores in different N－fertilized maize plots.The relationships among denitrification rate and N₂O flux with soil moisture,soil temperature and NO^-₃-N concentration in soil are analyzed,and losses of N－fertilizer caused by denitrification and N₂O emission are calculated.The results show that denitrification loss from soil is 0.67～3.85kg/hm² during the growing period of maize,percentage of denitrification loss from N－fertilizer is 0.5%～1.5%,the total N₂O emission is 0.55～1.42kg/hm²,and N₂O emission coefficient of N－fertilizer is 0.2%～0.5%.