氮肥用量对青海甘蓝型春油菜产量及氮肥利用效率的影响

Effect of nitrogen fertilizer on yield and nitrogen utilization efficiency of spring rapeseed in Qinghai

为了明确青海甘蓝型春油菜对施用不同用量氮肥的肥效响应程度,以青杂2号为材料,在青海省春油菜主产区通过田间小区试验,研究不同氮肥用量对油菜产量、氮素含量、氮素累积量及氮肥利用效率的影响。结果表明:与不施氮对照相比,施用氮肥60-240kg/hm^2,油菜籽粒产量可提高13.7%-25.6%;茎秆产量可提高1.1%~8.6%,角壳产量可提高16.7%-30.4%。施用氮肥可显著增加油菜植株不同器官内的氮素含量及氮素累积量(<0.05),氮素总累积量可由不施氮时的93.6kg/hm^2增至143.1kg/hm^2。油菜成熟期,地上部氮素累积量分配规律为:籽粒>茎秆>角壳,分别占总累积量的73.0%,16.8%和10.2%。随氮肥施用量的增加,氮素偏生产力(PFP N)、氮素农学效率(AE N)、氮素表观利用率(RE N)均呈下降趋势。因此,在青海省甘蓝型春油菜区以120kg/hm^2作为推荐施氮量,可达到高产和环境友好的目的。

In order to understand the response of spring rapeseed (Brassica napus L.) to the application of different amounts of nitrogen fertilizer, Qingza No. 2 was used as research material to study the response of spring under the different rate of nitrogen fertilizers. Field experiments were carried out to investigate the influence of nitrogen fertilizers on the yield, concentration of nitrogen, accumulation and nitrogen utilization efficiency of spring rapeseed in Qinghai plateau. Compared to the control treatment with zero N application, seed yield ranged from 13. 7 % to 25. 6 %, stem yield varied from 1. 1 % to 8. 6 %, and pod yield changed from 16. 7 % to 30. 4 % after N application increased from 60 kg/hm^2 to 240 kg/hm^2. The results indicated that N application promoted the concentration and accumulation of nitrogen at different tissue of spring hybrid spring rape significantly. Using N fertilizer,accumulation of nitrogen enhanced from 93. 6 kg/hm^2 to 143. 1 kg/ hm^2 compared to control treatment. In spring rapeseed mature period,the order of accumulation of nitrogen was seed >stem >pod,it took up 73. 0%,16. 8% and 10. 2% respectively of total accumulation of nitrogen. With the increase of the rate of N fertilization, partial factor productivity (PFPN), agronomic use efficiency (AEN),apparent recovery efficiency (REN) declined apparently. To meet the demands of high yield and environment-friendly ,120 kg/hm^2 of N fertilizer was the optimum in spring rapeseed production area of Qinghai province.