棉花是我国乃至世界最重要的纤维作物。棉花生产为我国国民经济发展作出了重要贡献，但因生产成本上升、种植效益下降，其持续生产面临现实挑战。我们认为，以缩短棉花生产周期、保证棉花产出水平不变为前提的棉花“省工、减肥”高效生产，是解决上述问题、确保棉花生产持续发展的重要途径。但是，棉花高强度物质积累、产量形成的群体建成、冠层结构有何特点？其养分利用、光合作用、及碳氮代谢等生理过程有何特点？本项目拟选用大田推广品种，采用大田和盆栽试验、同位素示踪、色谱-质谱联用等技术，研究棉花高效生产群体建成，1.与播种时间的动态关系及其生理过程，2.与肥料用量的关系及其生理过程，3.与养分三要素协同利用的关系及其生理过程，从而从群体建成和代谢生理的角度明确棉花“省工、减肥”的高效生产机理。本项目的实施，不仅可从理论上阐明棉花高强度资源（物质、能量）利用的机理，而且可为棉花高效持续生产提供理论依据。

Cotton is the most important fiber crop in China or even in the world. Cotton production has attributed greatly to the national economy development. However, its sustainable production is facing real challenges such as cost enhancement and profit decreasing. We conclude that cotton production with reduction in labor and fertilizer by shortening the production period and ensuring the equal yield will be an important way to meet the challenge and realize cotton sustainable development. Nevertheless, what are the features in population formation and in canopy structure for cotton plants fast accumulation in biomass and efficient distribution to reproductive organs? What are the characteristics in physiological process in nutrients utilization, photosynthesis, and carbon/nitrogen metabolism? The project will, by adopting commercial cotton variety, field and pottery trial, isotope tracing, and chromatography – mass spectrometry, deal with the relationships between the canopy formation for cotton efficient production population and 1.dynamic sowing dates and its physiological process, 2.fertilizer rates and its physiological process, 3.coordinating utilization of 3 major nutrients and its physiological process. The project will elucidate the theory for cotton efficient production in canopy formation and in metabolism physiology. Therefore, this project will not only help us to understand the mechanism of cotton plant for efficient resource (matter and energy) utilization, but also lay a solid foundation for cotton sustainable and efficient production.