秋浇定额对土壤盐分变化的影响分析

Effect of Autumnal Irrigation Quota on Soil Salinity Variation

秋浇是内蒙古引黄灌区传统的秋后淋盐、春季保墒的一种特殊的灌水制度。本文通过分析不同秋浇定额灌溉条件下土壤盐分的变化,研究了土壤盐分变化与秋浇定额的关系。结果表明:20 cm以上土层的土壤含盐量变化与秋浇定额存在较好的相关关系,秋浇前后、秋浇前～春播前秋浇定额在1 725 m3/hm2时土壤含盐量减少最多,秋浇定额小于1 725 m3/hm2时,土壤含盐量的减少量随秋浇定额的增大而增大,秋浇定额大于1 725 m3/hm2时,土壤含盐量的减少量随秋浇定额的增大而减少;20 cm以下土层含盐量变化则不完全受秋浇定额的影响。

The autumnal irrigation is a special irrigational system in Yellow River irrigation area of the Inner Mongolia so as to dilute soil salinity and keep the soil moisture of the following spring.Through analyzing soil salinity variation on condition of different autumnal irrigation quota,this article studied the correlativity of soil salinity variation and autumnal irrigation quota.The result indicated that the correlativity of soil salinity variation and autumnal irrigation above the soil layer of 20 cm is better;during the period of autumnal irrigation and from autumnal irrigation to spring sowing,the autumnal irrigation quota is 1 725 m^3/hm^2,the soil salt content reduces most;when the autumnal irrigation quota is less than 1 725 m^3/hm^2,the decrement of the soil salt content increases along with the increment of autumnal irrigation quota;when the autumnal irrigation quota is more than 1 725 m^3/hm^2,the decrement of the soil salt content decreases along with the increment of autumnal irrigation quota;the variation of soil salt content below the soil layer of 20cm is affected incompletely by autumnal irrigation quota.