沙地衬膜小麦土壤水分动态的研究

通过对景电二期灌区衬膜沙地土壤水分动态监测，分析其土壤水分剖面变化及土壤水分动态变化规律，得出沙地衬膜能显著起到节水保墒作用，且随衬膜深度的增加而提高。在作物牛长初期，村膜沙地土壤水分在垂直分布差异上不明显，这是由于幼苗阶段、小麦植株矮小，植物蒸腾耗水员较小的缘故；而在植物生长中后期，小麦地上部分牛长旺盛，根系庞大，蒸腾耗水最大，从而造成土壤含水最上层高于下层。衬膜沙地因土层变浅，限制了土壤的储水深度，因此，在衬膜沙地栽培作物时，需要通过农田水分调控技术来实现水源的合理利用，其技术原则是：a少量多灌，并严格按照小麦各牛育期需水量的多少决定灌溉量；b应以当地资源条件和农m水分状况为依据，建众适宜的作物种植方式、耕作体系和轮作制度；c通过培肥地力调节农田水分关系．提高作物光合作用强度和水分利用率．以调节土壤的持久供水能力。

Study on dynamic variation law of film-bottomed sandy soil moisture

Based on observating film-bottomed sandy soil moisture in the Electronicirrigated Area of Jingtai Plain and analysing soil moisture profile, it had reached the conclusion the film-bottomed technique improved the sandy soil moilsture, the more deepth, the higher amount of preservation of soil moilsture. During the pre-stage of growth period, the film-bottomed sandy soil moisture distribution is not clear to the profile,due to young plant wheat and lower tempefature and weak evaPoration. Behind the growth period, the pall of wheat on the ground is grosse and the root system is large. Thus, the violent transpriation not only cause amoullt of waters to lose but-also lead to the large amount of water in high level of sandy soil than the lower's. Therefore, we must take many rightly measure to make good use of water resource.