不同氮肥喷涂吡啶对夏玉米田氮素利用及土壤N2O排放的影响

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.

Effects of nitrapyrin-nitrogen (N) fertilizer application rates on N utilization and N2O emission in summer maize field.

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.