关键词: 移栽油菜, 直播油菜, 氮肥, 施肥效果, 适宜施氮量

Abstract: 【Objective】In order to provide a scientific basis for rapeseed fertilization, the effects of nitrogen fertilization on growth and yield of transplanting and direct-seeding rapeseed were studied to seek the characteristics of nitrogen nutrition for direct-seeding rapeseed, and to compare and understand the difference of nitrogen fertilizer effect and optimum fertilizer rate between the transplanting and direct-seeding planting patterns.【Method】A field experiment of nitrogen fertilization on transplanting and direct-seeding rapeseed was conducted in Shayang of Hubei during 2009-2010, field surveys and yield analysis were taken, and the optimum nitrogen fertilizer rate was determined based on the fertilizer effect model. 【Result】 Due to the different planting patterns, the plant morphology and growth characteristics were quite various for transplanting and direct-seeding rapeseed. Transplanting rapeseed developed better in all aspects than direct-seeding rapeseed, the advantage of individual plant was obvious, but the direct-seeding rapeseed had group advantage, and the yield level was similar to that of transplanting rapeseed. Nitrogen fertilizer promoted effectively growth and increased significantly yield of both transplanting and direct-seeding rapeseed. Meanwhile, effects of nitrogen fertilizer on rapeseed were different in two planting patterns, and the growth and yield formation of transplanting rapeseed were more significantly influenced by nitrogen fertilizer. Direct-seeding rapeseed had a large root group, could uptake more nitrogen from soil, and the requirement to exogenous nitrogen was lower than that of transplanting rapeseed. The optimum fertilizer rates of transplanting and direct-seeding rapeseed in this experiment were 228.4 kg•hm-2 and 130.3 kg•hm-2, respectively.【Conclusion】 The plant morphology, growth and nitrogen effect of transplanting and direct-seeding rapeseed are obviously different. Compared to transplanting rapeseed, direct-seeding rapeseed requires less nitrogen fertilizer, and has high economic benefit when their yield are similar. Therefore, the direct-seeding rapeseed has better prospects for rapeseed production.

Key words: transplanting rapeseed, direct-seeding rapeseed, nitrogen fertilizer, fertilizer effect, optimum nitrogen fertilizer rate