基于电磁感应数据棉田土壤盐分剖面时空变异特征研究

Study on spatial and temporal variation characteristics of soil profile salt in cotton field based on EM38-MK2 data

针对新疆南疆塔里木河绿洲地区土壤盐渍化发生反复性与南疆水资源日益匮乏等问题,以该地区典型地块为研究对象,运用电磁感应仪快速获取土壤盐渍化信息技术,结合地统计插值对新疆塔里木河绿洲地区土壤盐分剖面类型进行研究,并用表观电导率ECv1.5与ECv0.75比值对研究区土壤盐分剖面进行分级并对土壤盐分剖面类型空间分布进行探讨。结果表明,不同时期ECv0.75数据在空间分布上均表现为强变异强度,棉花整个生育期,土壤盐分呈现累积状态。不同时期ECv1.5与ECv0.75比值半方差函数均符合指数模型,土壤盐分剖面空间自相关性从棉花播种前由随机性因素作用类型过渡到棉花花铃期的随机性与结构性共同作用类型,再转变为棉花收获后土壤盐分剖面由随机性因素作用类型。不同时期土壤盐分剖面类型空间分布图表明,土壤盐分剖面类型呈现底聚型-表聚型-底聚型状态分布。土壤质地、微地形、温度、地下水埋藏深度是造成土壤盐分剖面类型分布格局最直接的因素。该研究结果对灌溉制度的科学制定具有一定的指导作用。

Aiming at the repetition of soil salinization and the increasing scarcity of water resources in southern Xinjiang Tarim River Oasis Area,the soil salinity profile in the typical plot of this area was studied using electromagnetic induction instrument combined with statistical interpolation to obtain the soil salinization information technology quickly.The classification of soil salinity profile and the spatial distribution of soil salinity profile in the study area were discussed with the ratio of apparent conductivity ECv1.5 and ECv0.75.The results showed that the ECv0.75 data in different periods were strong variation intensity,and the salt showed being cumulative throughout the growth period of cotton.The semi-variance functions of ECv1.5 and ECv0.75 ratios were in line with the exponential model in different periods,and the spatial autocorrelation between the data was composed of stochastic factors and structural factors.The spatial distribution of soil salt profile types in different growth periods showed that the type of soil salinity profile presented the distribution of "bottom polymerization"-"table polymerization"-"bottom polymerization".Soil texture,microtopography,temperature and groundwater burial depth are the most direct factors causing the distribution pattern of soil salt profile type.The results of this study have a certain guiding role in the scientific formulation of irrigation systems.