秸秆还田对灌溉玉米田土壤反硝化及N_2O排放的影响

运用乙炔抑制技术研究了不同施氮水平下秸秆还田对灌溉玉米田土壤反硝化反应和氧化亚氮(N2O)排放的影响。结果表明,土壤反硝化速率及N2O的排放受氮肥施用、秸秆处理方式及其交互作用的显著影响。与秸秆燃烧相比,不施氮或低施氮水平时,秸秆还田可刺激培养初期反硝化反应速率及N2O排放,增加培养期间N2O平均排放通量;高施氮水平时,秸秆还田可降低反硝化反应速率及反硝化过程中的N2O排放。秸秆还田可降低反硝化中N2O/N2的比例。

Acetylene inhibition method was used to study effects of stubble incorporation and nitrogen fertilization on denitrification and N_2O emission in an irrigated maize soil.Stubble management was designed as stubble incorporation and stubble burn.Nitrogen fertilizer was applied with 5 rates: 0,100,200,300,400 kg/ha.Samples were taken after experiment has been set 4 years.Fresh soils were incubated at 85% WFPS(water filled pore space) with 1 kPa or no C_2H_2 for 8 d,and N_2O emission was measured during incubat...