一、灌区土壤次生盐渍化的概况据D. W. Thorne, H. B. peterson统计,全世界约有55%的土地分布在干旱及半干早气候带,这些地区雨量稀少,干旱气候带的年降雨量一般不足250毫米,半干旱气候带的年降雨量亦仅250—500毫米。因此,发展灌溉是促进这些地区农业生产发展的一项重要手段。据M. M. ElGabaly调查,近东地区,非灌溉地的小麦产量为0.5吨/公顷,粗粮0.4吨/公顷,豆科作物0.6吨/公顷,而灌溉地的产量则分别为1.24吨/公顷,1.47吨/公顷和0.97吨/公顷。事实证明,发展灌溉可使作物产量成倍增长。但是,灌溉不合理,灌水过多,就会限制植物 I. Introduction of Soil Secondary Salinization in Irrigation Areas According to statistics by DW Thorne and HB Peterson, about 55% of the world’s land is distributed in the arid and semi-dry antero-climatic zones with scarce rainfall and annual rainfall in arid climates Less than 250 mm, the annual rainfall in the semi-arid climate zone is only 250-500 mm. Therefore, the development of irrigation is an important means of promoting the development of agricultural production in these areas. According to the MM ElGabaly survey, in the Near East, non-irrigated wheat production was 0.5 tonne / hectare, coarse grain 0.4 tonne / hectare and legume crop 0.6 tonne / hectare, while irrigated land production was 1.24 tonne / hectare, 1.47 tonne / Ha and 0.97 ton / ha. Facts have proved that the development of irrigation can double crop yields. However, irrational irrigation, excessive irrigation, it will limit the plants