Study Of Field Experiment Of Soil Water Movement Under The Condition Of Straw Mulching Of Different Depth Of Crops

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.