追氮方式对寒地玉米干物质积累、转运及氮肥利用率的影响

Effects of Nitrogen Topdressing Methods on Dry Matter Accumulation,Translocation and Nitrogen Use Efficiency of Maize in Cold Zone of China

为了探讨寒地玉米最佳追氮方式,通过大田试验,在追氮总量115 kg hm-2不变条件下,测定玉米主要生育时期根、茎、叶干物质量;氮肥偏生产力、农学效率及氮肥利用率,分析不同追氮方式[不施肥(CK);不施氮肥(PK);基肥+追肥浅追一次(NPK+SD1);基肥+追肥深追一次(NPK+DD1);基肥+追肥深追二次(NPK+DD2)]对寒地玉米干物质积累、转运及氮肥不同利用率的影响。结果表明,灌浆期茎干物质达到最大值,较CK和PK分别提高43.42%~59.40%(P【0.1)和23.12%~36.84%(P【0.1);吐丝期叶干物质量达到最大值,较CK和PK分别提高33.31%~47.14%(P【0.1)和25.88%~36.96%(P【0.1)。不同追氮方式提高了寒地玉米茎、叶转运量、转运率及对籽粒总贡献率,且氮肥深追较浅追茎运转率提高4.3%~5.61%(P【0.5),对籽粒贡献率提高1.49%~2.04%(P【0.1);叶运转率提高3.75%~4.18%(P【0.5),对籽粒贡献率提高0.98%~1.09%(P【0.5)。较CK和PK产量分别提高78.0%~99.7%(P【0.1)和54.4%~73.2%(P【0.1),且氮肥深追较氮肥浅追产量提高8.76%~12.2%,以氮肥深追二次产量最高。氮肥深追较氮肥浅追偏生产力提高5.8~8.0 kg kg-1(P【0.5),农学效率提高5.8~8.0 kg kg-1(P【0.5),利用率提高了8.3%~10.7%(P【0.1)。综合看来,氮肥深追一次、氮肥深追二次有利于寒地玉米茎、叶干物质积累、运转及对籽粒贡献率,提高氮肥不同利用率,从而提高产量,且氮肥深追好于氮肥浅追,以氮肥深追二次效果最好。

To discuss the optimum nitrogen topdressing methods of maize in cold zone of Northeast China, keeping the same condition of total nitrogen application of 115 kg·hm-2, a series of field experiments were conducted with the different nitrogen topdressing methods(i.e. CK: no fertilizer; PK: P and K base fertilizer without N; NPK + SD1: N, P and K base fertilizer with once N surface topdressing; NPK + DD1: N, P and K base fertilizer with once N deep topdressing; NPK + DD2: N, P and K base fertilizer with twice N deep topdressing to investigate the effects of different nitrogen topdressing methods on dry matter accumulation, translation and nitrogen use efficiency of maize root, stem,leaf and its yield in cold area during the main growth stages. The results showed that stem dry matter reached the maximum in filling stage, which increased by 43.42% ~ 59.40%(P < 0.1) and 23.12% ~ 36.84%(P < 0.1) compared with CK and PK, respectively; Leaf dry matter reached the maximum in silking stage, which increased by 33.31% ~47.14%(P < 0.1) and 25.88% ~ 36.96%(P < 0.1) compared with CK and PK, respectively. The N topdressing methods improved the grain total capacity, transport rate and contribution rate of maize stem and leaf, meanwhile,compared to the N surface topdressing, the N deep topdressing increased stem transport rate by 4.3% ~ 5.61%(P <0.5) with the contribution rate to grain increasing by 1.49% ~ 2.04%(P < 0.1); Moreover, leaf transport rate increased by 3.75% ~ 4.18%(P < 0.5) with the contribution rate to grain increased by 0.98% ~ 1.09%(P < 0.5). Additionally,compared with the treatments of CK and PK, the yield increased by 78.0%-99.7%(P < 0.1)and 54.4% ~ 73.2%(P < 0.1),meanwhile, it increased by 8.76% ~ 12.2% compared with the treatment of NPK + SD1, with the highest yield in the treatment of NPK + DD2. Compared to the N surface topdressing, the partial productivity in the treatment of N deep topdressing increased by 5.8 ~ 8.0 kg kg-1(P < 0.5), with the agronomy efficiency increasing by 5.8 ~ 8.0 kg kg-1(P <0.5), and the utilization ratio increasing by 8.3% ~ 10.7%(P < 0.1). In general, the different nitrogen topdressing methods were good for dry matter accumulation, translation, assimilation of maize stem and leaf in cold zone. Improve the nitrogen utilization efficiency would improve the yield, and nitrogen fertilizer deep application was better than surface application, meanwhile, the treatment of NPK + DD2 had the best effect.