除草剂对氮肥反硝化损失与N2O排放的影响

在华北平原潮土上,采用原状土柱培养乙炔抑制法研究玉米地氮肥反硝化损失和N2O排放量以及喷施3种除草剂(乙莠、丁莠和旱锄)的影响.结果表明,氮肥的反硝化损失量为2.66kgN/hm2,占施肥量的1.77%;氮肥产生的N2O排放量为3.14kgN/hm2,占施氮量的2.09%,反硝化不是该地区旱作系统氮肥损失的主要途径,但氮肥的施用大大增加N2O排放量.喷施除草剂显著或极显著降低氮肥的N2O排放量和反硝化损失量,比单施尿素处理分别降低2.01~2.85kgN/hm2和2.56~3.16kgN/hm2.

Influence of herbicides on denitrification loss of nitrogen fertilizer and emission of N2O

The denitrification loss and N2O emission amount of nitrogen fertilizer and the influence of 3 herbicides spraying in the maize-cultivated land was studied in the dry-land of North China Plain, adopting the method of intact soil incubation and acetylene inhibition. The denitrification loss amount of nitrogen fertilizer was 2.66kg N/hm2, occupying 1.77% of nitrogen fertilizer applied; the N2O emission amount produced from the fertilizer was 3.14kg N/hm2, occupying 2.09% of nitrogen fertilizer applied; and denitrification was not the main pathway of nitrogen fertilizer loss in the dry cultivation system of the area; but nitrogen fertilizer applied increased greatly the N2O emission. Spraying herbicides markedly or very markedly decreased the N2O emission amounts and the denitrification loss amounts of nitrogen fertilizer, which reduced 2.01~2.85kg N/hm2 and 2.56~3.16kg N/hm2 respectively, compared with that of the treatment applying urea alone.