控释氮肥施用方式及用量对玉米干物质积累及子粒产量的影响

在大田条件下以不施氮为对照，采用随机区组设计了5个施氮水平，研究了控释氮肥施用方式及用量对玉米干物质积累、叶面积指数及子粒产量的影响。结果表明:施氮量在0~150 kg/hm2范围内，玉米干物质量、叶面积指数均表现为随施氮量的增加而增加，施用控释尿素处理玉米的干物质量、叶面积指数大口期前低于常规尿素处理，花后却显著高于常规尿素处理。该试验条件下，上述指标和施氮量均呈正相关关系。研究还表明，施氮量在0~150 kg/hm2范围内，玉米子粒产量随施氮量的增加而显著增加，增幅为5.0%~21.4%。施氮量为75 kg/hm2时，控释尿素底施、侧施比常规尿素分别提高6.7%和3.4%；施氮量增至150 kg/hm2时，控释尿素底施、侧施比常规尿素分别提高8.8%和1.9%。与常规尿素相比，控释尿素能更好地协调玉米的地上部生长，具有明显的“前控后保”效果，利于获得高产，而底施则可以显著提高这种效果。 

Effects of Methods and Rates of Controlled Release Urea on Dry Matter Accumulation and Yield of Maize

No nitrogen as control，five nitrogen rates were designed to investigate the effects of methods and rates of controlled release urea（CRU）application on the dry matter accumulation and yield of maize in a randomized design.The results showed that the dry matter accumulation and leaf area index were getting more increase with increasing of N application rate，compared with normal urea，CRU has obvious superiority.It could increase them before male tetrad stage，while decrease them after anthesis in the range of 0～150 kg/hm2.In the experiment，the targets went up along with the increasing of N application rate.The results also indicated the grain yield of maize was getting more increase with increasing of N application rate in the range of 0～150 kg/hm2，and it was increased by 5.0%～21.4%.Compared with the normal urea，the 75 kg/hm2 treatment of the grain yield was improved by 6.7%，3.4% under bottom application and side dressing between the rows of CRU and the 150 kg/hm2 treatment of the grain yield was improved by 8.8%，1.9%，respectively.In conclusion，using CRU can coordinate the growth of shoot to get higher grain yield，and increase of bottom application is benefit to improve the effects of CRU on grain yield.