Abstract: In order to select optimal coated ureas as single nitrogen application to replace conventional nitrogen application practice (preplant + side-dressing)，so as to improve the utilization rate of nitrogen. Using corn variety Bayu 11 as experimental material, this paper investigated the effects of different nitrogen sources (fertilizer types) and timing of N application on the soil inorganic nitrogen, corn yield and nitrogen use efficiency. The experiment was carried out as field experiment with six treatments, including control (CK), single application of preplant conventional urea (CU1), preplant conventional urea + side-dressing at stem-elongation of corn (CU2), single application of sulfur coated urea (SCU), single application of polymer-coated urea (PCU), and single application of 50% polymer-coated urea + 50% conventional urea (HPC). Ammonium nitrogen and nitrate nitrogen in soil of 1 m depth was measured according to the growth stages of corn. Corn yield was measured after harvest and the nitrogen use efficiency was calculated as well. The results showed that CU1 released nitrogen at higher rates at the initial stage. Though both SCU and PCU delayed the release rate of nitrogen, nitrogen release rate of SCU was clearly higher than that of PCU at the initial stage. Corn yield followed the order: PCU>HPC>CU2>CU1>SCU>CK, the yield increased by 46.3%, 38.8%, 29.5%, 25.8% and 16.9% than CK, respectively. While the nitrogen use efficiency followed the order: PCU>HPC>SCU>CU2>CU1, which increased by 49%, 43%, 39%, 36%, 25% than CK, respectively. It was concluded that both PCU and HPC significantly increased corn yield and nitrogen use efficiency. PCU and HPC could be replaced the traditional way of nitrogen application in production. The results provided theoretical basis and reference of production application for one-time nitrogen application in black soil.

Key words: nitrogen sources, corn yield, soil inorganic nitrogen, nitrogen use efficiency

摘要： 为了提高氮肥利用率，选择合适的包膜尿素（一次性基施）代替尿素（基肥+追肥），以玉米品种巴玉11为试验材料，研究不同氮源（氮肥品种）、不同施氮时期对土壤无机氮含量、玉米产量和氮利用效率的影响。田间试验设置空白（CK）、尿素基施（CU1）、尿素基施+追肥（CU2）、硫包膜尿素基施（SCU）、树脂包膜尿素基施（PCU）、50%树脂包膜尿素+50%普通尿素基施（HPC）共6个处理，测定不同生育时期1 m土体内铵态氮含量、硝态氮含量、玉米产量及氮利用效率。结果表明，与传统施氮方式相比（CU2），尿素一次性基施（CU1）处理前期氮素释放快，后期脱肥；两种包膜尿素均可延缓氮素释放，硫包膜尿素表现为前期氮素释放快的典型特征，树脂包膜尿素在整个生育时期表现较平稳氮释放。各处理产量表现为PCU>HPC>CU2>CU1>SCU>CK，相对于不施氮依次增产46.3%、38.8%、29.5%、25.8%、16.9%；氮肥利用率表现为PCU>HPC>SCU>CU2>CU1，利用效率依次为49%、43%、39%、36%、25%。树脂包膜尿素基施处理和50%树脂包膜尿素+50%尿素基施处理，可显著提高玉米产量和氮利用效率，可代替传统施氮方式应用于生产。研究结果为黑土区一次性施氮提供理论依据和应用参考。

关键词: 氮源, 玉米产量, 土壤无机氮, 氮利用效率