不同水质膜下滴灌棉田盐分空间变异特征  

Spatial Variability of Cotton Field Salinity under Mulched Drip Irrigation with Brackish and Fresh Water

作　　者：栗现文[1] 靳孟贵[1] 

机构地区：[1]中国地质大学环境学院,武汉430074

出　　处：《农业机械学报》2014年第11期180-187,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金资助项目(41172218)

摘　　要：为评价不同水质膜下滴灌棉田土壤盐分空间分布及变异性,采用EM38-MK2型电磁感应仪对微咸及淡水滴灌田块进行盐分调查。解译模型获得的土壤含盐质量比描述性统计特征表明,微咸水滴灌的积盐程度高于淡水滴灌,但其变异系数相对较小。采用GS+软件拟合最优半方差函数模型,微咸水处理为指数模型,淡水处理为高斯模型,均表现为强的空间相关性;微咸水处理变程大于淡水处理,增加了土壤盐分的空间相依性。Kriging空间插值及变异分析表明,淡水滴灌棉田土壤盐分微域及全域空间变异程度强于微咸水滴灌,二者均存在影响棉花出苗的盐斑。建议用水紧张时,可基于EM38-MK2型电磁感应仪的盐分调查结果,重点淋洗盐斑集中分布区域,以节水增产。Shallow brackish water is widely distributed throughout north and northwest China and could be rational used. To evaluate the spatial distribution and variability of cotton field salinity under mulched drip irrigation with brackish and fresh water in southern Xinjiang, electromagnetic induction EM38 - MK2 was applied to measure the apparent soil electrical conductivity. Statistical characteristics of soil salinity from the interpretation models of soil salinity showed that the scenario of brackish water irrigation had the higher salinity level and the lower variation coefficient than the fresh water irrigation. The optimal semi- variance models of brackish water and fresh water irrigation were exponential and Gaussian models respectively. Both models were characterized by strong spatial correlation. Compared with fresh water irrigation, the scenario of brackish water irrigation with the higher salinity level had the lager range variation and increased the spatial dependency of soil salinity. The spatial distribution of field salinity interpolated by Kriging method showed that both scenarios of brackish and fresh water irrigation had some filed parts with high salinity level, which would affect cotton emergence. EM38- MK2 would be suggested to investigate the field salinity distribution. According to soil salinity levels of different parts, amount of fresh water of flood irrigation for leaching salinity could be defined to save water and ensure the agriculture production.

关 键 词：微咸水膜下滴灌 干旱区 空间变异 电磁感应半方差函数 

分 类 号：S156.4[农业科学—土壤学]