Geochemical Distribution Characteristics of Different Land Form Types in Loess Hilly Areas

Based on geochemical test of soil samples from the Liang and Mao-Ruhe River valley profile in Pengyang and the Liang and Mao-Huluhe River valley profile in Xiji of loess hilly areas in southen Ningxia,the studies on the contents of constant element,trace element and effective state of trace element in differentplaces of different land forms have been conducted.Most constant elements are comparativelysteady,K~(+)and Na~(+)arerich in the terrace of river valleyand loss onloess slope;The contents of CaO and Fe_(2)O_(3)are comparatively less on the terrace in river valley becauseof the function of soilwaterand oxidizingand reducing condition;Mosttrace elements are comparatively steady in the soil,the contents of Ti、P、Zn、Ba:the top of hills in loess hilly areas the terrace in river valley;The content of B in soil: the top of loess hilly areas the slope of loess hilly the terrace in river valley;The effective state content of trace elements: the terrace in river valleythe top of hilly the slope of loess hilly.