两种追氮方式对砂壤质潮土夏玉米产量及氮肥利用率的影响

采用大田小区试验,在氮肥施用量200 kg N/hm2下,观测了夏玉米季两种追氮方式对夏玉米籽粒产量及氮肥利用率的影响,试验设置不施氮(CK)、常规拔节期一次性追氮(T1)、拔节期与大喇叭口期分两次追氮(T2)三个处理.结果表明,与对照相比,追施氮肥能显著增加夏玉米叶片的叶绿素相对含量、籽粒产量以及氮肥利用率.在总追氮量一定的情况下,分两次追氮(拔节期、大喇叭口期)无论在叶绿素相对含量、籽粒产量还是氮肥利用率等方面,均优于一次性追氮(拔节期).因此,在砂壤质潮土区域夏玉米拔节期和大喇叭口期分两次追施氮肥更有利于增加玉米籽粒产量和提高氮肥利用率.

Summer Maize Yield and Nitrogen Use Efficiency at Two Nitrogen Topdressing Ways in Sandy Loam Fluvo-aquic Soil Region

Under the field experiment condition,effects of two nitrogen（N）topdressing ways on summer maizeyield and N use efficiency were studied at the same amount of N application with 200 kg·ha^-1in summer maize season.There were three treatments including no fertilizer（CK）,once N topdressing in jointing period（T1）and twice Ntopdressing in jointing period and the bell-mouthed period（T2）. The result showed that compared with CK,the SPADvalue,yield and N use efficiency of N topdressing treatments were increased significantly. Under the same N applicationrate,compared with N topdressing only once in jointing period treatment,N topdressing at twice time in jointingperiod and the bell-mouthed period treatment could provide the higher SPAD value,yield and N use efficiency. Inconclusion,N topdressing at twice respectively in jointing period and the bell-mouthed period would be an optimizedN topdressing way for enhancing summer maize yield and increasing N use efficiency in sandy loam fluvo-aquic soilregion.