耕作期内土壤水分和盐分运动规律——试验设计及水盐变化

[目的]分析灌溉期内土壤水盐变化规律,为改进灌区耕作期灌溉制度存在的现行问题,土壤盐碱化治理以及研究节水型灌溉工程的实施对生态环境的影响提供科学指导。[方法]考虑土壤质地、灌溉方式、作物种植等因素进行试验点、观测点的布设,通过常规方法对水分变化、含水率、土壤盐分、地下水盐分等方面进行了计算分析,在此基础上,对其影响因子(灌溉方式、灌溉制度等)进行相关性分析。基于2a耕作期内时空变化监测数据分析土壤水分、盐分运动变化特点。[结果]耕作期土壤含水率随土层深度增加而增加,含水率变化频率随土层深度增加而减少。[结论]耕作期内,在地下水埋深较浅的情况下,过大的降雨量(灌水量)并不能得到更高的脱盐效率,甚至可能降低脱盐率,表层土壤呈现较明显的脱盐过程;地下水盐分变化与降雨关系密切。

Movement of Soil Moisture and Salt During Farming Period-Experiment Design and Water-Salt Movement Change

[Objective] The objective of this paper is to analyze the dynamic changes of soil water and salt during the farming period in order to provide the scientific guidance for soil salinization control and the implementation of water-saving irrigation project.[Methods] We designed the experiments according to the soil texture, irrigation methods, crop cultivation and other factors. We calculated and analyzed the variations in water content, moisture content, soil salinity and groundwater salt through the conventional methods. Based on 2 years observation data, we analyzed the dynamic changes of soil moisture, and salt movement.[Results] Soil moisture content increased with the increase of soil depth, and the change frequency in soil moisture content decreased with the increase of soil depth during farming period.[Conclusion] During the farming period, heavy rainfall(drop water) may reduce desalting efficiency, and the surface soil shows an obvious desalting when the groundwater are shallow. Changes in groundwater salinity are closely related to rainfall.