微咸水灌溉对土壤环境效应的预测研究

利用识别后的SWAP模型,探讨了微咸水灌溉条件下土壤水盐及其均衡要素的转化关系和土壤的积盐趋势预测。结果显示,两种灌溉定额下土壤盐分都有所增加,但淋洗灌溉定额下比正常灌溉定额下小麦、葵花和玉米模型土壤盐分分别降低了6.5%、0.7%、4%;小麦、葵花和玉米的相对减产率分别比正常灌溉定额下降低了1%、2%、6%。微咸水灌溉后在灌溉定额和灌溉水浓度不变的前提下,土壤盐分的积累随着时间的推移而呈递减趋势,大约在10a后盐分达到进出平衡状态,此时土壤的含盐量达到0.1852mg·cm^-3,比微咸水灌溉前增加0.0822mg·cm^-3。但仍属于轻度盐渍土（土壤含盐量0.126%）,不会对土壤水土环境产生较大的影响。

Prediction and Research of Soil Environment Effect Under Light-Saline Water Irrigation.

There are many researches on salt water irrigation technology, salt water utilization pattern, impact on crop yield and quality using salt water irrigation, adaptability of salt water irrigation, and salt water irrigation amelioration of soils, etc. In recent years, environmental effect caused by light salt water irrigation at the regional scale is concerned. Based on the field experiment in the Inner Mongolia Hongwei testing station, this paper introduced the SWAP model and discussed the conversion relation of soil water salt balance elements and soil salt accu- mulation trends on the conditions of light salt water irrigation. The prediction results indicated that both in the leaching quota and in the normal irrigation could lead to the increase of soil salt. But, in the leaching quota, the soil salt in the wheat model decreased 6.5%, 0.7% in the sunflower model, and 4% in the maize model comparing with the corresponding values in the normal irrigation quota. The decreasing rate of yield in the wheat, sunflower and maize decreased 1%, 2%, and 6%, respectively. On the condition of the saline water irrigation, unchanging the irrigation quota and the irrigation water concentration, the soil salt accumulation decreased as trend goes. After about 10 years, soil salt could reach the recharging and discharging balance. At that time, the soil salt content was 0.185 2 mg·cm^-3, and increased amount was 0.082 2 mg·cm^-3. But the soil still was belongs to the light salinity, and the light saline water irrigation couldn＇t affect the soil water environment signif- icantly. Through analyzing the simulation results, this paper indicated that light salt water irrigation was feasible in arid or semi-arid regions.