我国不同土壤Q/I特性及其供钾能力研究

用Ｑ／Ｉ方法对砖红壤、红壤、壏土、黑土和水稻土供钾特性进行了研究，结果表明，５ 种土壤对钾的缓冲性能（ＰＢＣＫ） 大小顺序为黑土＞ 壏土＞ 水稻土＞ 红壤＞ 砖红壤，５ 种土壤ＰＢＣＫ 和ＣＥＣ之间密切相关，可以用回归方程ｙ＝ －８ ．３２ ＋ ５．９２ｘ 表示，相关系数（ｒ） 为０．９８４ 。黑土和壏土以云母和蛭石２∶１ 型粘粒矿物为主，较多的楔形区域导致了较高钾特殊吸附（Ｋｘ） 值；而红壤和砖红壤具有较低Ｋｘ 归于粘粒矿物以高岭石为主。土壤的供钾强度指标（ＡＲＫｅ０） 大小顺序为砖红壤＞ 红壤＞ 壏土＞ 水稻土＞ 黑土，该值不仅取决于该土壤交换性钾含量，同时由粘粒矿物决定。

Study Q/I Characteristics and K-supplying Power in Different Chinese Soils

Studies on K supplying power in Latosol soil, Red earth, Lou soil, Black soil and Paddy soil were carried out with Q/I method. The result showed that the sequence of potential buffering capacity (PBC K) of five soils is as follows: Black soil>Lou soil>Paddy soil>Red earth>Latosol soil. There is a good relationship between PBC K and CEC. The regression equation is y=-8 32+5 92x with a correlation coefficient r of 0 994. The wedge zone originated from abundant mica and vermiculite resulted in the high specific affinity (K x) for K in Black soil and Lou soil. Whereas, the low specific affinity (K x) in Latosol soil and Red earth is attributed to high proportion of kaolinite. The sequence of potassium intensity AR K e 0 is Latosol soil>Red earth>Lou soil>Paddy soil>Black soil.Potassium intensity is determined not only by exchangeable potassium but also by clay minerals in soils.