Chemical properties of Andisols which are distributed in Northern Japan, Aleutian islands, Alaska, Washington and Oregon State were studied using Andisol TU database. These data include tephra -derived Spodosols in 31 percent. Average contents of oxalate-extractable Al (Al_O) and Fe_O/2 (Fe_O/2) were 2.1 and 0.67 percent and these values correspond to 21 and 21 percent of average total Al and Fe/2 contents, respectively. The frequency distribution of Al_O/Al_P, where Al_P is pyrophosphate-extractable Al, has two maxima at 0.1-0.4 and 0.7-1.0, suggesting the stability of two kinds of Andisols (allophanic and nonallophanic Andisols). The Al/Si atomic ratio of allophane ((Al_O-Al_P)/Si_O) was mostly 2. The amount of Al_O +Fe_O/2 which attains 85 percent of phosphate retention percentage ranged between 1.0 and 2.5 percents. Aluminum in Al-humus complex has higher reactivity with phosphate than Al in allophane and imogolite. The pH(H_2O) values of A horizon soils ranged between 4.2 and 6.2. Alic samples showed lowest pH(H_2O) values, humus-poor nonalic samples highest, and humus-rich nonalic intermediate. The C/Al_P atomic ratio of A horizon soils except the uppermost layers was about 13. On the other hand, one mole of negative charge developed for every 39 moles of OC at pH7. Assuming that humus has 4 moles of carboxyl groups for every 40 moles of OC according to Yonebayashi and Hattori (1988), three fourths of the carboxyl groups are complexed with Al and do not show negative charge and remaining one fourth is free and develops negative charge at pH7.
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