粘土質土壌における土粒子表面物性値の断面内変動

抄録

Experimental study on the changes of the surfacial properties of soil particle in two clayey soil profiles was made. Investigated surfacial properties are "H_2O surface area" determined by water adsorption method and cation and anion exchange capacity (CEC, AEC) determined by "Wada et al"'s method. Followingly, the relation between these surfacial properties and the main soil constituent material, the relation between surfacial properties and the general chemical and physical properties of soil, were considered. Selected soil profiles are "Kamitaisei" soil and "Komukai" soil, located in Hokkaido, the former is volcanic ash soil and the latter is pseudogley soil. The results obtained are summarized as follows : 1) In "Kamitaisei" soil, the changing pattern of "H_2O surface area" in profile agreed almost with that of AEC, and these values was largest in C_2 and IIC horizon. 2) In "Komukai" soil, the changing pattern of "H_2O surface area" in profile agreed with that of CEC, and these values was largest in C_2g horizon. 3) The main factor which affects the above mentioned changes in profile was the content of amorphous matter in "Kamitaisei" soil and the content of clay plus silt in "Komukai" soil. 4) The CEC determined by "Schollenberger" 's method in "Kamitaisei" soil was considerably larger than that of "Wada et al" 's method, whereas both CEC in "Komukai" soil almost agreed. 5) The development of macroscopic soil structure in soil profile was estimated by the relative value of the packing of soil particle based on the "H_2O surface area".