[译者的话 ]　干旱、半干旱半湿润地区 ,灌区的土壤盐碱化是一个世界性的问题。灌溉渠系和田间灌水的渗漏引起地下水位的上升。地下水通过蒸发从土壤表层散失 ,地下水和土壤中的盐分将留在土壤中。在地下水位上升和盐分积累到一定程度后 ,将导致土壤的沼泽化和盐碱化。虽然通过 [Translator’s remark] Arid, semi-arid and semi-humid areas, irrigated soil salinization is a worldwide problem. Leakage of irrigation canals and field irrigation causes an increase in groundwater level. Groundwater is dissipated from the soil surface by evaporation and groundwater and salt in the soil will remain in the soil. After the groundwater table rises and the salt accumulates to a certain extent, it will cause the soil to swamp and salinize. Though passed