To reduce the N2O emission from soil and enhance N utilization by crop, a field experiment was carried out to study the effects of nitrapyrin-N fertilizer application rates (0, 180, 270, 360 kg N·hm-2) on soil N2O emission and N apparent loss, grain yield and N utilization of summer maize. Results showed that the soil N2O emission under different N fertilizer treatments mainly occurred in periods from sowing to seedling, and from jointing to tasseling. Soil N2O emission peaks were observed after basal and top dressing events. Maize yield increased with N fertilizer rates but there was no significant difference between 270 and 360 kg N·hm-2, and the net income of these two treatments was 5209 and 5426 yuan·hm-2, respectively. Compared with no N fertilizer treatment, the N uptake in the N fertilizer treatments was increased by 109.6%-134.1%. The treatment of 270 kg N·hm-2 had the highest agronomic N efficiency and N use efficiency, but the N apparent loss was low. The treatment with nitrapyrin-N fertilization rate of 270 kg N·hm-2 appeared to be the optimal rate to obtain high maize yield and N use efficiency, and low soil N2O emission and N apparent loss.
为减少土壤N2O排放,提高作物氮素利用,采用田间试验法研究了不同氮肥用量喷涂一定比例的吡啶(0、180、270、360 kg N·hm-2)对夏玉米生育期内土壤N2O排放和氮素表观损失、籽粒产量及氮素利用的影响.结果表明:不同氮肥用量下喷涂吡啶的土壤N2O排放主要集中在播种-苗期和拔节-抽雄期,基肥和追肥后均会出现显著的土壤N2O排放通量高峰.随氮肥用量增加,玉米产量不断增加,但270和360 kg N·hm-2间无显著差异,2种施氮量下的玉米分别净增收5209和5426元·hm-2.与不施氮肥比,各施氮处理下的玉米籽粒吸氮量提高幅度为109.6%～134.1%.各处理间的氮肥农学效率和氮肥利用率均以氮肥喷涂吡啶270 kg N·hm-2较大,而土壤氮素表观损失较小.氮肥喷涂吡啶在270 kg N·hm-2时玉米增产增收,氮肥利用效率较高,土壤N2O排放和氮素表观损失较少,是一种较为合理的氮肥调控施用技术.
Keywords: N 2 O emission; N utilization; nitrapyrin-N fertilizer; summer maize; yield.