塔里木河上游地区土壤水盐变化与作物的关系

RELATIONSHIP BETWEEN THE CHANGE OF SOIL MOISTURE-SALT AND CROPS IN THE AREA AT THE UPPER REACHES OF TARIM RIVER

本文利用塔里木河上游灌区阿克苏水平衡站的有关试验观测资料，对绿洲农田地下水、土壤中水和盐的运动及植物耐盐性进行对比分析，总结了土壤水盐运动的某些规律。

The original soil of the oasis in Tarim Basin is desert soil with high salt content.Groundwater level has been universally raised by irrigation for some years- The moisture and salt move active1y because of the permeation and violent evapotranspiration of irrigation water. It not only affects water balance, but also promotes the movement and accumulation of salt in soil, and is harmful to the growth of crops. Aksu Water Balance Experimental Station is 1ocaled in the area at the upper reaches of the Tarim River. The water table there has a seasonal change, i. e., it is the highest in summer and the lowest in winter and the difference is over 1.7m. Irrigation water can seep down to 2m under the earth surface, but groundwater can not supply water to the roots of crops if its level is deeper than 2m, so sometimes the farmland has to be over irrigated. The zone of 20-40cIn deep under ground surface is the dense zone of the roots of crops, and irrigation water can permeate down to there easily for satisfying the water requirement of crop growth. However,that zone is the accumulating zone for salt after irrigation- The goal of saving water and escaping from the salt harmfulness to crops will be able to be achieved after soil is improved. The relative salt tolerance is different from different crops, cotton has a strong salt to1erance and wheat has a weak one. Most of natural plants can live under a condition of low water table (but not deeper than 5m) in Tarim Basin. Some arid plants can even grow depending on salt water with a mineralization'of lower than log/l. Different crops should be se1ected to plant according to different salt contents in soil. the drained water can be used for irrigation the salt-enduring vegetation so as to make water resources into full use and protect natura1 vegetation.