不同灌溉方式和作物类型对西北干旱区耕地土壤盐渍化的影响

土壤盐渍化是西北干旱区耕地发展的主要限制因素之一。近10年来,新疆石河子垦区耕地的灌溉方式和作物类型都发生了很大的变化,并对耕地土壤的盐渍化产生了影响。为此,基于不同作物类型、不同灌溉方式下典型耕地地块的实验数据,采用配对T检验、曼-惠特尼U检验等统计分析方法,研究了垦区灌溉方式和作物类型对耕层土壤盐分的影响。结果表明:(1)漫灌相对于滴灌来说,会降低土壤耕层的总含盐量,但是却使得耕层表层盐分积聚;漫灌条件下盐分在水平方向分布比较均匀,而滴灌条件下其分布离散程度较高。(2)作物类型对土壤耕层总含盐量及盐分在耕层土壤中的水平和垂直分布影响均不显著,短期的作物改种(棉地改为玉米地)对土壤耕层盐分含量没有明显影响。

Effects of Different Irrigation Modes and Crop Types on Soil Salinization in Shihezi Reclamation Area, China

Soil salinization is one of limiting factors on the development of arid farmland in the northwestern China.During the past 10 years,the irrigation modes and crop types of Shihezi,a typical arid irrigation area,has changed significantly,which has had a great influence on the soil salinization of farmland.Base on the experiment data of farmland topsoil salt on different irrigation modes and crop types,this article analyzed the effects of irrigation modes and crop types on the soil salt content and its distribution in different tilth layer,using statistical analysis techniques such as T test and Mann-Whitney U test.The results showed that:(1)Firstly,the irrigation mode had relatively more impacts on the soil salt content and its distribution in plow-layer than the crop type.(2)Secondly,the flood irrigation mode could reduce the total salinity of tilth soil but would cause salt accumulation in topsoil surface.On the other hand,in different tilth layers(0~10 cm and 10~20 cm),soil salt distribution was relatively more even in the horizontal direction under the condition of flood irrigation,while under the drop irrigation situation,the soil salt presented a discrete distribution.(3)Lastly,different crop types had no significant effects on both total salinity of tilth soil and the salt horizontal and vertical distributions in different tilth layers.Moreover,a short term crop replant(from cotton to corn) had no observable effects on the tilth soil salinity.