普通尿素与控释尿素单施及其配施对直播油菜产量和氮肥利用率的影响

为探明控释氮肥在直播油菜上的应用效果和施用技术,研究成都平原冲积性水稻土上普通尿素与控释尿素单施及其配施对油菜产量和氮肥利用率的影响。2011—2012年,在相同施氮量(N 189 kg/hm~2)条件下,设置普通尿素单施(PU)、控释尿素单施(CU)、普通尿素与控释尿素各50%配合施用(PCU)3个处理。2012—2013年,在相同施氮量(N 180 kg/hm~2)条件下,按普通尿素与控释尿素配施比例33%、50%、67%(PCU33、PCU50、PCU67)和一次性基施氮肥(T1)、基肥+1次苗期追肥分次施氮(T2)设置6个处理(PCU33T1,PCU33T2,PCU50T1,PCU50T2,PCU67T1,PCU67T2)。结果显示:同等施氮量(N 189 kg/hm~2)下,与普通尿素单施处理(PU)相比,普通尿素与控释尿素配施处理(PCU)具有相对较高的籽粒产量(3 166.9 kg/hm~2)、氮肥农学利用率(8.0 kg/kg)、氮肥偏生产力(16.8kg/kg)、氮肥贡献率(47.9%)和氮肥表观利用率(54.5%)。在相同施氮量(N 180 kg/hm~2)和普通尿素、控释尿素配施条件下,PCU33、PCU50处理的籽粒产量(162 9.0、182 0.1 kg/hm~2)和氮肥利用率均显著或明显高于PCU67处理的。结果表明,本试验条件下,普通尿素与控释尿素配施比例为33%~50%,并采用氮肥一次性基施有利于直播油菜高产、高效。

Effects of single and combined application of controlled release coated urea and conventional urea on yields and nitrogen fertilizer use efficiency of direct sowing rapeseed (Brassica napusL.)

Two field experiments were carried out to explore the effects of single and combined application of controlled release coated urea and conventional urea on yield and nitrogen fertilizer use efficiency of direct sowing rapeseed (Brassica napusL.) at a paddy field in Chengdu plain. During the period from 2011 to 2012, three experiments were conducted with controlled release coated urea (CU), conventional urea (PU), and 1:1 of coated urea and conventional urea (PCU)) at the same N fertilizer amount (189 kg/hm2) in form of single basal application. During the period from 2012 to 2013, six experiments were set up, they were combined application of conventional urea and controlled-release coated urea the ratio of 33%, 50% and 67%, labeled by PCU33, PCU50 and PCU67 respectively; single basal application (T1), basal application and one time topdressing (T2) at the same N fertilizer amount (180 kg/hm2).The results indicated that seeds yield(3166.9 kg/hm2), agronomic efficiency of N fertilizer (AEN, 8.0 kg/kg), partial factor productivity of N fertilizer(PFPN,16.8 kg/kg), N fertilizer contribution rate(NCR, 47.9%)and apparent recovery efficiency of N fertilizer(REN, 54.5%)in treatment PCU were relative higher than that in treatment PU at the same amount of N application (189 kg/hm2). Seed yields in treatment PCU33 and PCU50 were 1629.0 and 1820.1 kg/hm2, respectively, which were obviously higher than that in treatment PCU67 at the same amount of N application (180 kg/hm2), the same situation was true for nitrogen fertilizer use efficiency in treatments PCU33 and PCU50 compared with treatment PCU67. Therefore, combined application of 33% to 50% controlled release coated urea as single basal application could be beneficial to high yield and use efficiency for direct sowing rapeseed in Chengdu plain.