Studies on Humus of Tea Soil (Part 2)

Forms of Humic Acid of Tea Soil, Uncultivated Soil and Cultivated Soil

Abstract

The property of humus among tea soil, uncultivated soil and cultivated soil derived from Fuji volcanic ash soil, diluvial Makinohara red-yellow soil, and the "Kuroboku" soil was examined.
The results were summarized as follows:
1. The form of humus by SIMON's method, methoxyl content of humus and difference spectrum of humic acid among tea soil, uncultivated soil and cultivated soil were examined.
These investigations did not show any cha-racteristics of tea soil, but indicated the characteristics of soil category.
2. The amount of true humic acid extracted with 0.1% sodium oxalate solution (the modified SIMON's method) was as follow :
tea soil ?? cultivated soil>uncultivated soil. The amounts of A type and B type in true humic acid (by SIMON) in these soils were as follows:
A type was more than B type in Makinohara red yellow soil, B type was a little more than A type in the "Kuroboku" soil and A type was very little in Fuji volcanic ash soil.
3.The difference spectra of A and B types of humic acid (by SIMON) in red yellow soil indicated a lignin-like pattern but that of "Kuroboku" or Fuji volcanic ash soil did not indicated such a pattern.