On the basis of field investigation, soil sampling and chemical analysis, classical statistical analysis was applied in order explore the salinity characteristics of takyric solonetz in Ningxia Yinbei Region in our country for investigating the basic salinity conditions of takyric solonetz and establishing predictive models of main salinity characteristics from electrical conductivity under drip irrigation. Results showed that the main salt ions accumulated significantly towards to the top layers in soil profile, salt contents decreased with the increase of soil depth. Cl- and Na+ were the dominant anions and cations respectively in soil, especially in the top layers, and HCO3- content increased gradually in the soils below 100 cm. SAR in the surface soil was above 15 (mmol/L)0.5 and pH values between 8.5-10. Na+ content had the most significant correlation with Cl', with a correlation coefficient of 0.902 (P<0.01), and followed by SO42- and HCO3-. Significant correlations (P<0.01) between the electrical conductivity of saturation paste extracts (ECe) and Cl Na+, total soluble salt (TSS) content, SAR were found. Mathematic models were developed to calibrate Cl", Na+, TSS content and SAR from ECe by using linear regression respectively with 150 samples. Verified with other 150 samples, the prediction accuracy was reliable, so the models could be used to evaluate the contents of Cl-, Na+ and TSS, as well as SAR, economically and fast, and finally could be served as predictive methods for the salinity condition of takyric solonetz under precise amelioration with drip irrigation in this region.%为探明龟裂碱土的基本盐分状况,并建立在滴灌利用条件下基于电导率的土壤主要盐分性质的预测模型,本文在野外调查、取样和化学分析的基础上,利用经典统计分析方法,对我国宁夏银北地区龟裂碱土盐分特征进行了研究.结果表明,龟裂碱土剖面内盐分含量总体呈现“表聚”现象,主要盐分离子含量随深度增加逐渐降低.Cl-和Na+是该土壤中最主要的阴阳离子,且在上层土壤中表现尤为突出,HCO3+含量在100 cm以下的土层中逐渐增加.表层土壤钠吸附比(SAR)值较大,均在15(mmol/L)0.5以上,pH值在8.5～10之间.Na+与Cl-的相关性最强,相关性系数为0.902 (P＜0.01),Na+与SO42-、HCO3-的相关性次之.土壤饱和浸提液电导率(ECe)和Cl-、Na+、可溶性总盐(TSS)含量及SAR值显著正相关(P＜0.01).土壤Cl-、Na+、TSS含量及SAR可由自变量为ECe的数学回归方程来表达,且预测精度可靠,可快速、经济地模拟和预测该地区土壤Cl-、Na+、TSS含量及SAR值,为本区域滴灌精准改良利用条件下龟裂碱土的盐渍化状况评价提供参考.
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