氮素调控对玉米氮素同化过程及产量的影响

氮素调控措施与作物氮素吸收利用和产量密切相关，但目前关于不同氮素调控措施对玉米主要生育期氮素同化过程的影响仍不清楚。以郑单958为试验材料，设置不施氮肥（CK）、传统施肥（CN）、氮肥+生物炭（SN）和氮肥+硝化抑制剂DMPP（DN）4个处理，分析不同氮素调控对玉米氮素同化过程中铵态氮和硝态氮含量、硝酸还原酶（NR）和谷氨酰胺合成酶（GS）活性、游离氨基酸和可溶性蛋白含量以及氮素利用率和产量的影响。结果表明：DN和SN处理较传统施肥处理均可以提高玉米植株体内硝态氮和铵态氮含量、NR和GS活性；DN和SN处理显著提高灌浆期谷氨酸、游离氨基酸和可溶性蛋白含量；DN处理成熟期籽粒的氮素积累量显著高于SN和CN处理，分别显著增加18.4%和30.0%；DN处理产量最高，SN次之，二者并无显著差异，但相较CN处理分别显著增产1 483.0和1 154.2 kg·hm^-2。两种氮素调控均促进了玉米对氮素的吸收，显著提高氮肥吸收利用率，其中硝化抑制剂处理氮肥吸收利用率最高且显著高于其他处理。综上，生物炭或硝化抑制剂配施氮肥，可以促进玉米氮素同化和转运过程，显著提高玉米产量和氮肥利用效率，综合产量、籽粒氮素积累量和氮肥吸收利用率，硝化抑制剂配施氮肥可作为淮河流域玉米高产高效的栽培措施。

Effects of nitrogen regulation on nitrogen assimilation process and yield of maize

Nitrogen regulation measures are closely related to crop nitrogen uptake, utilization and yield, but the effects of different nitrogen regulation measures on nitrogen assimilation process in the main growth stage of maize still keep unclear. In this study, four treatments were set up: no nitrogen fertilizer (CK), traditional fertilizer application (CN), nitrogen fertilizer and biochar (SN) and nitrogen fertilizer and nitrification inhibitor DMPP (DN) by using Zhengdan 958 as materials, to analyze the effects of different nitrogen regulation on ammonium nitrogen and nitrate nitrogen contents, nitrate reductase (NR) and glutamine synthetase (GS) activities, free amino acid and soluble protein contents during the nitrogen assimilation, nitrogen utilization and the yield of maize. The results showed that both DN and SN treatments increased the nitrate nitrogen and ammonium nitrogen contents, NR and GS activities in maize plants compared with CN. Both DN and SN treatments significantly increased the contents of glutamate, free amino acid and soluble protein contents during the filling stage. Nitrogen accumulation in DN significantly increased by 18.4% and 30.0%, respectively than SN and CN in grains at the maturity stage. The yields of DN and SN increased by 1 483.0 and 1 154.2 kg·hm^-2, respectively, as compared to CN. Both nitrogen regulation promoted nitrogen uptake in maize and significantly improved nitrogen fertilizer uptake and utilization efficiency. The nitrogen fertilizer uptake and utilization efficiency of DN was the highest and significantly higher than the other treatments. In conclusion, biochar or nitrification inhibitor with nitrogen fertilizer promoted the process of nitrogen assimilation and transport in the maize, and significantly improved the maize yield and nitrogen fertilizer use efficiency. Therefore, combining the yield, grain nitrogen accumulation and nitrogen fertilizer uptake efficiency, nitrification inhibitor with nitrogen fertilizer can