低地力下施氮量对直播和移栽油菜产量和经济效益的影响

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

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。

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.