中文摘要：

本文利用谐振腔微扰技术在微波L波段对低盐土壤的介电常数进行了测量。通过测量实验室制备的不同含盐量以及四种阳离子组分的土壤样品的介电常数,研究介电常数实部和虚部与盐度、温度、盐组分的关系,得出结论：介电常数实部和虚部均随温度升高而增大,随着含盐量的增加,其虚部受温度影响变大;实部与含盐量及其种类无明显相关性,虚部与含盐量呈现曲线关系,并与盐种类存在相关性。在实验测量数据基础上,预测了被动微波遥感对盐碱土特性的识别能力,结果表明：利用微波辐射计能够有效地分辨低盐土壤含盐量的变化,并且在土壤盐度大于5‰的情况下,利用多波段微波辐射计可实现分辨土壤盐种类的分析,这为利用微波遥感进行土壤盐碱化程度监测,提供了一定的参考。

英文摘要：

This paper measured the dielectric constant for low salt soil in the L-band microwave by resonant cavity perturbation technique. By measuring the dielectric constant of soil samples with different salt content and the compo-sition of four cationic prepared in the lab, and studying the relationships between the real part and imaginary part of dielectric constant and the salinity, temperature, and salt composition, it is concluded that： both the real part and imaginary part of dielectric constant increase with growing temperature, with the increasing of salt content, the imagi-nary part has a greater influence by the temperature;the real part has no obvious relation with the salt content and the categorization, the imaginary part has a curve relationship with the salt content, and is relative to the categorization of salt. On the basis of experimental measurement data,the ability of passive microwave remote sensing to identify the characteristics on saline-alkali soil was prospected, the results showed that：the salt content change of low-salt soil can be effectively identified by using microwave radiometers, and under the situation of more than 5‰salt content in soil, analysis on the identification of salt categorization in soil can be realized by multi-band microwave radiometer, which provides certain reference for the monitoring on the degree of soil salinization by microwave sensor.