【作者】 吴旭春；

【导师】 虎胆·吐马尔白；

【作者基本信息】 新疆农业大学 ， 水文学及水资源， 2007， 硕士

【摘要】 本论文根据土壤水动力学理论、SPAC(土壤-植物-大气连续体)理论和空气动力学理论,通过对作物不同地下水埋深不同位置秸秆覆盖条件下土壤水分运动试验,确定了非饱和土壤水分运动基本参数。根据根系调查结果和根量分布特点,建立了相应的根系吸水模式,建立了秸秆覆盖条件下,有作物生长的垂向一维土壤水分运动的数学模型,对蒸发和降雨或灌溉条件下土壤水分运动,进行了数值模拟预测,计算值与实测值吻合较好,表明所建立的数学模型是可靠的,数值方法是可行的,上边界条件的处理和所选参数是合理的。在试验和理论研究的基础上,分析研究了不同地下水埋深不同位置秸秆覆盖条件下,节水保墒效果和盐分运移规律。研究表明:(1)秸秆覆盖能有效减少棵间蒸发量,增加有效水储量,具有明显的节水增产效应;(2)在同一地下水埋深条件下,地表覆盖秸秆保墒效果较距地表30cm处覆盖秸秆的效果好;(3)距地表30cm处覆盖秸秆具有压盐和防止返盐的作用,这对于盐碱地治理,在农田中防止产生盐碱化,提高土地生产力和农业综合生产能力都具有十分重要的意义。更多还原

【Abstract】 In this paper, according to the theory of soil water dynamics, SPAC and aerodynamics, the paper determines the basic parameters of soil water movement under unsaturation, by the experiment of soil water movement under the condition of straw mulching of different depth and the condition of different buried depth of phreatic water levels. According to the investigation of root system and the distribution of root weight, the corresponding form of soaking water for root system is decided. The paper develops one-dimensional vertical numerical model of soil water movement under straw mulching of crops, and seeks its numerical solution, simulates soil water movement under both evaporation and rainfall. The results indicate that the values of computation and the experimental data are of consistency, the numerical model effective, the numerical technique feasible, the processing for the upper boundary, and the parameters chosen reasonable. On the basis of the experiment and study of theory, the paper analyzes water-salt transport regulation and the effect of saving water under the condition of straw mulching of different depth and the condition of different buried depth of phreatic water levels.The study results show that as follows: (1)there is the effect of saving water and increasing yield under mulching of crops; (2) the effect of saving water under the surface mulching is good on the same groundwater table, comparing with its under straw mulching of 30cm depth; (3)there is the effect of preventing from soil salinization under the condition of straw mulching of 30cm depth. This measure is much important means about preventing farmland from soil salinization, increasing the productivity of land and enhancing agricultural comprehensive productivity.更多还原