极端干旱区葡萄深层坑渗灌灌溉机理研究

In China's extreme arid region, the serious shortage of water resources is the primary factor that restricts agricultural development. Due to its special soil and climate conditions, all kinds of existing irrigation methods almost cannot effectively improve the present situation that local water resources for irrigation waste seriously. The technique of Drip irrigation can't make the utilizing rate of irrigation water effectively improve because of surface evaporation loss significantly. According to the regional characteristics, the applicant improved the deep pit irrigation on the basis of pit irrigation, and conducted preliminary study. This technology is to use the capillary of small tubular outflow irrigation system to supply water for emitter that buried in certain depth below the surface - a deep pit , this irrigation method make the irrigation water reach to crop root distribution of soil layer where relative dense infiltration through the infiltrating hole of emitter, and can effectively reduce surface water evaporation. The application according to the research of indoor simulation test study ,which under the conditions of different pit forms and different soil conditions of moisture movement rule system in the extreme arid region of Gobi soil, establish the three-dimensional model of irrigation soil moisture for deep pit irrigation. Through the study of root distribution characteristics of field mature grape root distribution, establish the three-dimensional model, and couple the model of irrigation soil moisture and grape root distribution model, come up with the calculation method for design deep pit irrigation, and provide theoretical basis for deep pit irrigation system design.

我国极端干旱区，严重缺水是制约农业发展的首要因素。由于其特殊的土壤和气候条件，现有的各种灌水方式都无法有效改善当地灌溉水资源的严重浪费现状，滴灌技术也因显著的地表蒸发损失而使得灌溉水利用率无法有效提高。申请人根据该地区特点在坑渗灌基础上改进发展成深层坑渗灌灌水技术，并进行了初步研究。该技术是利用小管出流灌溉系统的毛管向埋设在地表以下一定深度处的灌水器- - 深坑进行供水，从而使灌溉水通过灌水器上的渗水孔向作物根系分布较为密集的土壤层中入渗的一种灌溉方法，可有效减少地表蒸发。本申请通过对极端干旱区戈壁土壤条件下不同深坑形式和不同土壤环境条件水分运动规律进行系统的室内模拟试验研究，构建深层坑渗灌灌水的三维土壤水分运动模型。通过对大田成龄葡萄的根系分布特征研究，建立根系分布三维模型，并将土壤水分运动模型与葡萄根系分布模型进行耦合，提出深层坑渗灌设计计算方法，为深层坑渗灌灌水系统设计提供理论依据。

深层坑渗灌是针对新疆极端干旱区葡萄种植的特殊情况而提出的一种节水灌溉技术，本项目主要通过室内和大田实验，探究了深层坑渗灌条件下土壤水分的入渗规律，研究了深层坑渗灌条件下成龄葡萄的根系情况，探明了根系分布与土壤水分的空间分布的关系。结果表明：在相同入渗时间内，累积入渗量随土壤容重或初始土壤含水量的增大而减小，而随水深或开孔率的增大而增大。临界开孔率为7.82%，在临界开孔率以下，灌水器开孔率或灌溉水深或土壤初始含水量越大，水平和垂直最大湿润距离越大，而土壤容重越大，水平和垂直湿润锋越小；在深层坑渗灌条件下并未发现优先流的发生；建立了各灌水要素影响下累积入渗量、水平和垂直最大湿润锋的预测模型；构建了深层坑渗灌条件下成龄葡萄根系分布的三维模型，并建立了根系分布与土壤水分运动的耦合模型。