控释尿素施用方式及用量对夏玉米氮肥效率和产量的影响

在大田条件下以不施氮为对照,研究了施氮量为75和150kgN·hm-2条件下,普通尿素底施、控释尿素底施和侧施对夏玉米光合性能、氮肥效率和产量的影响.结果表明:与普通尿素相比,相同施氮水平下,包膜控释尿素处理玉米果穗叶光合速率、叶绿素含量、硝酸还原酶活性、籽粒灌浆速率均显著提高,玉米籽粒产量比普通尿素平均提高9.5%;与控释尿素侧施相比,底施使玉米籽粒产量提高6.2%.包膜控释尿素处理的氮肥农学利用率(AE)和偏生产力(PFP)比普通尿素平均分别提高74.5%和11.0%;与包膜控释尿素侧施相比,底施使AE和PFP分别提高26.8%和5.7%.控释尿素施用量较高时,玉米光合性能得到改善,产量、AE和PFP显著提高;与控释尿素侧施相比,底施对玉米产量、AE和PFP的增加效果更显著.

Effects of different application modes and rates of controlled release urea on fertilizer nitrogen use efficiency and grain yield of summer maize

A field experiment was conducted to study the effects of different application modes (bottom application and side-dressing) and rates (0，75，  and 150 kg N·hm^-2) of controlled release urea on the photosynthetic capability, fertilizer nitrogen use efficiency, and grain yield of maize (Zea mays L.). Compared with conventional urea (U), the controlled release urea (CU) at same application rates increased the leaf photosynthetic rate, chlorophyll content, nitrate reductase activity, and kernel filling rate significantly, and promoted the grain yield by an average of 9.5% (P<0.05). Bottom application of CU induced a 6.2% higher grain yield than side-dressing CU. The average agronomic efficiency (AE) and partial factor productivity (PFP) of CU were 74.5% and 11.0% higher than those of U, and bottom application of CU increased the AE and PFP by 26.8% and 5.7%, respectively, compared with side-dressing CU. Higher application rates of CU improved the photosynthetic capability, and increased the grain yield, AE, and PFP. Bottom application of CU could significantly increase the grain yield, AE, and PFP of maize, compared with side-dressing CU.