Irrigation and drainage development of deserts in China

本研究由以下三个研究主题组成.桑迪荒漠开发利用中的水资源利用：在沙坡头沙漠试验研究站试验田，采用排水式蒸渗仪，采用水量平衡法估算滴灌条件下大豆的蒸散量。在桑迪上，用黄河泥沙覆盖土壤表层，可提高土壤持水量、大豆产量和蒸散量。在桑迪田中，少量水的频繁施用减少了深层渗漏损失。通过四年的大豆和玉米种植试验，证明了农村居民点污水处理后农业利用的可行性.桑迪荒漠耕作的土壤管理：分析了平罗高地土壤的化学性质。在地下水位高的情况下，农田的盐分积累是公认的小麦产量较低。收获季节后大量地表水的施用降低了土壤电导率的值.沙坡头木本植物的耐旱性与径向生长利用p-v曲线法研究了9种木本植物的耐旱性差异。沙冬青、中间锦鸡儿和黄柳的耐旱性较强。对5种木本植物在定期灌溉条件下的径向生长进行了解剖学研究。胡颓子属植物的径向生长具有周期性循环。angustifolia：和崖柏，而银白杨表现出稳定的增长。樟子松和旱柳在生长季出现一次生长停滞。

This research is composed of the following three subjects of study.1. Water resources utilization for development of sandy deserts :In the experimental field at the Shapotou Desert Experiment and Research Station, evapotranspiration from soybeans was estimated by the water balance method using the drainage type lysimeters under the condition of drip irrigation system. The water holding in the soil, soybean yield and evapotranspiration in a sandy field increased by covering the soil surface with silt contained in the Yellow river. Application of the small amount of water at frequent intervals decreased the deep percolation losses in a sandy field. Feasibility of agricultural utilization of treated wastewater from a rural settlement was proved by the experiments of soybean and corn culture during four years.2. Soil management for cultivation of sandy deserts :The chemical properties of soil at Pingluo upland field were analyzed. In the case of high groundwater level, the salt accumulation of the field was recognized with lower harvesting of wheat. Application of the, large amount of surface irrigation water after the harvesting season decreased the value, of electric conductivity in the soil.3. Drought tolerance and radial growth of woody species in Shapotou.Differences of drought tolerance among nine woody plants were investigated using the p-v curve method. The drought tolerance of Ammopitanthus mongolicus, Caragana intermedia, and Salix gordejevii was remarkable in all of the species. Anatomical studies on radial growth of five woody species maintained by periodic irrigation were also investigated. The periodic cycle of radial growth was observed in Elaeagnus. angustifolia : and Thuja orientalis, whereas Populus alba showed constant growth. In Pinus sylvestris and Salix matsudana the stagnation of growth occurred once in growing season.