王少华 刘涛 周雄 任涛 李小坤 鲁剑巍

摘要：为了探究低地力下直播和移栽油菜（Brassica napus L.）氮肥施用效果和适宜施氮量，设8个施氮处理（0、45、90、135、180、225、270、360 kg/hm2），研究直播和移栽条件下施氮量对油菜产量和经济效益的影响。结果表明，低地力条件下，直播和移栽油菜不施氮处理产量分别仅为140 kg/hm2和613 kg/hm2；当施氮量分别为206.0 kg/hm2和249.2 kg/hm2时达到最高产量，最高产量分别为2 525 kg/hm2和2 899 kg/hm2。施氮显著提高了直播和移栽油菜的产值和纯收益，当施氮量超过270 kg/hm2后不再增加。相较于移栽油菜，直播油菜产值虽然平均降低了1 347元/hm2，但纯收益却增加了482元/hm2。低地力条件下，直播油菜依然能节省43.2 kg/hm2氮肥，提高纯收益最高达972元/hm2。

关键词：低地力；油菜（Brassica napus L.）；直播；移栽；氮肥用量；产量；经济效益

中图分类号：S565.4；S147.22 文献标识码：A 文章编号：0439-8114（2018）07-0041-03

DOI：10.14088/j.cnki.issn0439-8114.2018.07.009

Effects of Nitrogen Application Rates on Yield and Economic Benefit of Direct-Sowing and Transplanting Rapeseed under Low Soil Fertility

WANG Shao-hua1，LIU Tao2，ZHOU Xiong1，REN Tao2，LI Xiao-kun2，LU Jian-wei2

（1.Wuxue Bureau of Agriculture，Wuxue 435400，Hubei，China；

2.College of Resources and Environment，Huazhong Agricultural University，Wuhan 430070，China）

Abstract： To investigate nitrogen application effects and suitable N application rate of direct-sowing and transplanting rapeseed （Brassica napus L.） under low soil fertility condition，8 different N levels （0，45，90，135，180，225，270 and 360 kg/hm2） were set，and the effects of N application rates on rapeseed yield and economic benefit were studied under direct-sowing and transplanting. The results showed that，under low soil fertility condition，the yield of direct-sowing and transplanting rapeseed without N fertilizer were only 140 kg/hm2 and 613 kg/hm2，respectively； the maximum yields were reached when N application rates were 206.0 kg/hm2 and 249.2 kg/hm2，respectively， and the maximum yields were 2 525 kg/hm2 and 2 899 kg/hm2，respectively.The output value and net profit of direct-sowing and transplanting rapeseed were significantly increased by N fertilization and no longer increased when the nitrogen application rate exceeded 270 kg/hm2. The output value of direct-sowing rapeseed decreased by 1 347 yuan/hm2 on average compared with transplanting rapeseed， but the net profit was increased by 482 CNY/hm2. Direct-sowing rape could save 43.2 kg/hm2 N fertilizer and increased net profit up to 972 CNY/hm2 under low soil fertility condition.

Key words： low soil fertility； rapeseed（Brassica napus L.）； direct-sowing； transplanting； N application rate； yield； economic benefit

直播和移栽是現阶段中国油菜（Brassica napus L.）栽培的两种主要种植模式[1]。随着劳动力条件以及生产力水平的影响，油菜的栽培方式发生了重大转变[2]。直播具有省工省时，便于机械化生产等优点，是当前油菜发展的主要方向[1，2]。但是，相较于移栽油菜，直播油菜个体生长较弱，受环境、养分缺乏的影响更大[3，4]。因此，对于如何保证直播油菜高产高效提出了更大的挑战。

氮素是限制作物生长的主要矿质营养元素，尤其是对于需氮量较高的油菜而言[5]。直播和移栽油菜对氮肥的响应存在显著差异，不施氮时直播油菜减产幅度高达到96.9%，远高于移栽油菜[6]。而不同地力条件下，两种种植模式对氮肥的响应并不一致。目前研究主要在中高地力水平条件下开展[7，8]，对于直播油菜而言，地力水平也是限制其生产以及对氮肥响应的关键因素。……