南疆盐渍化地区棉花水氮迁移机理及效应模拟研究

Cotton is the most important oasis farming commercial crop for Southern Xinjiang, and the cotton yield of Xinjiang is 40% of the total of the whole nation; but, because of the strong illumination, lack of rainfall and serious drought and salination of the soil in Xinjiang, how to improve the utilization efficiency of water and nitrogen under the condition of widespread natural drought in Southern Xinjiang is the key problem for cotton industry to develop with high efficiency. Under the background of widespread soil drought and serious soil salination in Southern Xinjiang, using cotton-an important commercial crop-as study object, according to soil-plant-air (SPAC) continuum analysis theory, fully considering the cotton canopy water evaporation, root distribution characteristic, soil water distribution, soil nitrogen distribution and so on, and the influence of salinity and excess fertilization to the migration of water and nitrogen, this project has studied the simulation of root distribution, of soil water migration, of nitrogen transfer and transformation process, and the simulation method and model of crop growing process, and has clarified the transfer characteristic of water and nitrogen fertilizer between soil and cotton roots. By using model simulation to describe the actual quantitive relation between the cotton absorbing volume of water and nitrogen, and the volume of fertilization and the different watering model, this project has revealed the water and nitrogen transfer mechanism of cotton in drought and salinity area of Southern Xinjiang, has set up the dynamic model of the migration-transformation and combined effect of soil water and nitrogen, and has supplied the theoretical foundation to guide cotton watering and fertilizing.

棉花是新疆南疆绿洲农业最重要的经济作物，新疆棉花产量占全国棉花总产的40%，但新疆地区的光照强、雨量少、土壤干旱与盐渍化严重，如何在南疆普遍干旱的自然条件下提高水氮的利用效率是棉花产业高效发展面临的重要问题。本项目在南疆土壤普遍干旱和盐渍化严重的背景下，以重要的经济作物棉花为研究对象，根据土壤—植物—大气（SPAC）连续体的分析理论，充分考虑棉花冠层水分蒸散、根系分布特征、土壤水分分布、土壤氮分布等因素，以及盐分、过量施肥对水氮迁移的影响，研究根系分布模拟、土壤水分运移模拟、氮素迁移转化过程模拟、作物生长过程模拟方法及模型，阐明水分、氮肥在土壤和棉花根系间迁移特性，用模型模拟描述棉花实际吸收的水、氮量与施肥量、不同灌溉模式间的定量关系，揭示南疆干旱、盐渍化地区的棉花水氮迁移机理，建立土壤水、氮迁移转化与综合效应的动力学模型，为指导棉花灌溉和施肥提供理论依据。

棉花是新疆南疆绿洲农业最重要的经济作物，新疆棉花产量占全国棉花总产的40%，但新疆地区的光照强、雨量少、土壤干旱与盐渍化严重，如何在南疆普遍干旱的自然条件下提高水氮的利用效率是棉花产业高效发展面临的重要问题。本项目在南疆土壤普遍干旱和盐渍化严重的背景下，以重要的经济作物棉花为研究对象，根据土壤—植物—大气（SPAC）连续体的分析理论，充分考虑棉花冠层水分蒸散、根系分布特征、土壤水分分布、土壤氮分布等因素，以及盐分、过量施肥对水氮迁移的影响，研究根系分布模拟、土壤水分运移模拟、氮素迁移转化过程模拟、作物生长过程模拟方法及模型，阐明水分、氮肥在土壤和棉花根系间迁移特性，用模型模拟描述棉花实际吸收的水、氮量与施肥量、不同灌溉模式间的定量关系，揭示南疆干旱、盐渍化地区的棉花水氮迁移机理，建立土壤水、氮迁移转化与综合效应的动力学模型，为指导棉花灌溉和施肥提供理论依据。