【摘要】 田间试验研究了不同土壤氮素供应水平和底追比例对玉米籽粒产量、土壤硝态氮和农田氮素平衡的影响。与农民习惯施肥(N 240 kg.hm-2,基肥和大喇叭口追肥为1∶2)相比,氮肥减量10%(N 216 kg.hm-2)和20%(N 192 kg.hm-2)处理的玉米产量并没有降低,而氮肥利用效率显著增加。氮肥减量后移可使耕层无机氮供应较好地与作物吸收同步,降低收获期0～100 cm土层的硝态氮积累,减少氮素的田间表观损失,提高氮肥利用效率。在本试验条件下,氮肥减量20%(N 192 kg.hm-2),基追比例1∶3∶1处理的植株产量、地上部植株氮肥吸收利用率、氮肥农学利用率均较高,0～100 cm土层未出现硝态氮明显累积,氮素表观损失量最少,是最佳施氮运筹模式。更多还原

【Abstract】 Field experiment was conducted to investigate the effect of reducing and postponing of nitrogen fertilizer on yield,plant N uptake,soil N supply,utilization and N balance in maize.Results showed that grain yield was no significant difference with N application of 10% and 20% reducing,while the N efficiency was increased.The reducing and postponing N application could improve synchronization of soil N supply and crop demand during maize growing stage,while NO-3-N accumulation of 0~100 cm soil profile and apparent N loss in maturity stage decreased and the N efficiency was increased.In conclusion,treatment N 192C which nitrogen fertilizer rate was 192 kg·hm-2 and the ratio of base and topdressing was 1∶3∶1 had higher grain yield and N using efficiency and minimized apparent N loss and the risk of soil nitrate leaching,which would be one of the most appropriate nitrogen fertilizer applying regimes in maize production in local region.更多还原