摘要
土壤中的可溶性盐离子是限制作物生长的因素之一,土壤复介电常数是测定土壤可溶性盐的一个重要指标。本文利用谐振腔技术,测量了4种电解质水溶液的介电常数,给出了25℃时Na^+、Cl^-、SO2-4、CO2-3和HCO-35种离子的复影响因子。利用各离子的复影响因子,可以将计算溶液介电常数实部的Collie介电模型直接用于计算土壤溶液的复介电常数。为了检验模型的准确性,本文还模拟配制了氯化物型、硫酸盐型和苏打型共41种多离子的土壤溶液,并用单一的电解质NaCl、Na2SO4和NaHCO3水溶液的影响因子来分别替代复杂的氯化物型、硫酸盐型和苏打型盐渍土土壤溶液的复合影响因子。将改进后的Collie介电模型计算介电常数值与模拟配制的41种土壤溶液的测量结果进行相关性分析t检验,其P均为0.85以上(大于0.05),无显著性差异,两组数据获得了很好的一致性。因此,本研究结果对于建立微波遥感监测盐渍土壤和盐湖水体的盐度的介电模型奠定了坚实的物理基础和实用基础。
Soluble salt ion in the soil is one of the factors restricting the crop growth.The soil complex dielectric constant is an important indicator for determining the soluble salts in the soil.In this paper,we measured the dielectric constants of 4 electrolyte aqueous solutions by the resonant cavity technique,and obtained complex influence factors with 5 ions including Na^+,CI-,SO2-4,CO2-3 and HCO-3 at 25℃.By using the complex influence factor of each ion,we directly applied the Collie dielectric model to calculate the real part of the dielectric constant of the electrolyte aqueous solution.In order to test the accuracy of the model,we simulated 41 soil solutions of chloride type,sulfate type and soda type;substituted the influence factors of single electrolyte NaCl,Na2SO4 and NaHCO3 aqueous solutions for the complex influence factors of chloride type,sulfate type and soda type saline soil solutions,respectively.We used correlation analysis t test to calculate the dielectric constant value of the improved Collie dielectric model and simulated the measurement results from the above 41 soil solutions.The results showed all the P values were above 0.85 with no significant differences(P>0.05).The data of the two groups showed a good consistency.Therefore,the results would lay a solid foundation to establish a microwave remote sensing dielectric model for monitoring salinity of saline soil and salt lake water.
作者
宫燕
刘宝江
宋开山
GONG Yan;LIU Baojiang;SONG Kaishan(Northeast Institute of Geography and Agroecology,CAS,Changchun 130102,China;University of Chinese AcademySciences,Beijing 100049,China)
出处
《土壤与作物》
2020年第1期83-93,共11页
Soils and Crops
基金
国家自然科学基金项目(41571355,41730104)资助.
