土壤2012，Vol.44Issue(2)：242-252,11.
不同有效钾提取方法的原理与效率比较
Comparing Principles and Efficiency of Different Methods for Available Potassium Extraction
摘要
Abstract
Principles and factors affecting the efficiency of different methods for extracting available K from six potassium-bearing minerals were investigated in current study. These methods included salt solutions, cation exchange resins and NaBPtu methods. The results showed that the effectiveness of K extraction from minerals by salts was mainly dependent on the ion type, concentration and pH value of the solution. Different salts had different preferential effect on K release from various minerals. NH4+ saturation led to the collapse of the interlayer structure of the minerals and restrained non-exchangeable K (NEK) release remarkably. The effectiveness of K extraction by cation exchange resins method was mainly related to the ion type used to saturated resin beads and somewhat to the shaking speed used. Comparing with Ca2+, H+ and Na+ saturated resin had stronger K exchanging capacity from solution. For eliminating the effect of film mass transfer resistance on K exchange by resins, a shaking speed higher than 120 r/min was recommended. The solubility product constant of KBPh4 was 2.40x10-8 (25℃) based on the data got in current study. Without NaCl, NaBPh4 concentration was the main factor affecting the effectiveness of K. extraction from minerals. According to the mechanism and efficiency of different methods, ammonium salts are suitable for evaluating K availability in soils with high content of exchangeable K. However, non-ammonium salts which can extract a small portion of NEK under long time extraction procedure, is superior to ammonium acetate to evaluate K. availability in soils containing NEK available to crop. Cation exchange resins which can also extract NEK are more suitable for in situ research of soil K movement, but the procedure is relatively tedious. Different portion of NEK could be efficiently extracted with the NaBPh4 method via modification of the K extracting power of the method The NaBPh4 method is assumed to be a good method for evaluation of available K in various soils in future.关键词
有效钾/提取方法/阳离子交换树脂/四苯硼钠/提取效率Key words
Available potassium, Extraction method, Cation exchange resin, NaBPh4, Efficiency of extraction分类
农业科技引用本文复制引用
刘宏鸽,王火焰,周健民,杜昌文,陈小琴..不同有效钾提取方法的原理与效率比较[J].土壤,2012,44(2):242-252,11.基金项目
公益性行业(农业)科研专项经费项目 (201203013)、国家自然科学基金项目(NSFC40971176)、国际植物营养研究所(IPNI)和国际钾肥研究所(IPI)项目资助. （农业）
