关键词: 前促后稳, 氮肥综合管理, 高产高效, 冬油菜

Abstract: Oilseed rape is one of the predominant oil crops in China. Yangtze River Basin is the key winter oilseed rape production region in China, where the specific climatic conditions, soils and cultivation practices induce the different characteristics of soil nutrient supply, crop growth and nutrient demand. High crop yield, high economic benefit and high nutrient use efficiency are the determinants of agricultural production and sustainable development. Asynchrony between oilseed rape nitrogen (N) demand and soil N supply in space and time is the major reason that excessive N or deficient N input is the most important limiting factor of rapeseed yield and economic benefit. Optimal N fertilization is critical to achieve high seed yield and high N fertilizer use efficiency. In this paper, the authors reviewed the recent perspectives on oilseed rape N management, including crop N uptake, soil N supply, the critical N fertilizer application methods and the matching techniques. Further, considering the characteristics of crop growth and soil N supply, an integrated N management strategy, of which the key is “promotion in early and stabilization in late” to match crop N uptake and soil N supply, is put forward. The core content of the strategy includes (1) adjusting the timing and proportion of N fertilization and N sources to satisfy N requirement in the seedling period, focusing on soil N supply to promote N transfer and re-utilization since stem elongation period; (2) Depending on soil N supply under different rotations and/or crop straw incorporation, coordinating the distribution of N fertilizer in whole growing season; (3) Synergistic interaction with other practices including optimal plant density, fertigation, application with other nutrients and mechanization to obtain high seed yield and high N fertilizer use efficiency.

Key words: promotion in early and stabilization in late, integrated N management strategy, high yield and high use efficiency, winter oilseed rape