Study For Soil Water Salt Movement Under Drip Irrigation With Film Mulch Of Cotton

Agricultural development and sustainable development of the major constraints, and salt and land salinization. Generally do not produce deep seepage drip, can not use irrigation water leaching the basic salt, salt transferred only in the soil can not be eliminated. Sustainable agricultural development based on consideration of Xinjiang, long-term use of drip irrigation may be a potential ecological risk of secondary salinization. Thus, different years of drip irrigation has become an oasis of water and salt transport for sustainable agriculture research priorities and hot issues. In this paper, 121 Mission Shihezi example, select a typical drip irrigation plots in 6 different years of this follow-up survey for 2 years, through the collection before sowing, seedling stage, flowering, harvest field test data, analysis of the film under drip irrigation under Water and Salt Transport of the field. Freezing and thawing in winter field experiment to study the effects of salt in the winter years of drip irrigation of cotton fields and accumulation in migration law. This study achieved the following:(1) RETC model using the formula has been related to soil water characteristic curve.(2) Different years soil moisture drip irrigation cotton boll overall trend is the biggest of water, the smallest harvest moisture content, water content of seedling and center before sowing, the period before sowing cotton in the seedling, boll, harvest water rate in the vertical direction, the general trend is 0-20cm depth of water containing the minimum rate of soil water content,20-40cm growing to 40cm of water content at most of the growth,40-60cm at the maximum water content is also sometimes Large,40-60cm of water at a transition zone. Then drip irrigation reduces deep percolation because of the reason.60cm depth in water content with depth the following increases. When the impact of groundwater by the water content at 100cm will occasionally rise.(3) Drip irrigation in the horizontal direction of the water content and salinity is a gradual process of change, emitter at the top of the soil moisture content, salinity minimum. Descending horizontal moisture is dripping at the Central→narrow line between film, and in the emitter at the Central→film→narrow line between the variation of salinity is from small to large.(4) Spring planting a large number of antecedent land surface evaporation has no irrigation, the soil salt accumulation in the trend of the cotton from seed to start to drip irrigation, especially in the summer increase in the number of irrigated cotton crops in order to ensure normal growth. Cycle throughout the cotton growing cotton under drip irrigation will continue to wash shower, wash cotton in summer as drip irrigation season salt leaching. Since the fallharvest crops into the high temperature has not dripping irrigation wash shower, a large number of surface soil water evaporation causes salt accumulation in surface drip irrigation cotton, so autumn is the season of salt drip irrigation cotton back.(5) Through drip irrigation at different ages for two consecutive years of growth of cotton in different changes in different soil salinity can be compared with the growth of plant life in different layers of soil profile Drip years will slowly salt evenly to each soil layer. Drip irrigation at different ages, the average salt content in soil and plant life of the plant life as the graph shows the growth of salinity in the soil into:Start planting a large salt content in the soil, and salt content dropped to a certain extent, and then will be a growing trend.(6) As the frozen layer of down like frozen layer will gradually moving down the frozen layer of salt distributed more evenly, and freezing level is not below the seasonal changes in the depth of the impact of salt. Most of the freezing process of salt along with the freezing of soil water remaining in the frozen layer. That the winter salt in the incubation period. When the winter snow melts in the spring, snow on the surface of a wash shower 0～10cm role in the surface of the snow pressure salt effect is obvious. When complete facilities permafrost, surface evaporation gradually strong at the surface 0～10cmc soil becomes very dry hard. Quietly accumulated in the freezing winter, the salt layer, and then with the evaporation of soil moisture accumulation on the soil surface, so that a sharp increase in salt content, salt mainly in 0～10cm of soil. Plots in the spring of 2001 years of salt throughout the soil profile is greater than the winter freezing and thawing of the salt content, soil salt accumulation in spring period.