抄録
After their morphological characters, paddy field soils were classified into three types, Half-bog soils, Meadow soils, and Gray lowland soils ; the types being subdivided into soil kinds, ten in total. (see Table 1 & 2; & Map) Of each soil type, some suggestions or remarks were made to increase the productivity in the follwing way. (Half-bog soil) : Drainage is, first of all, required. When completed, the drainage may be feared to cause soil nitrogen to become excessively available for the plant to an extent to hinder the normal growth of plant. Heavy application of phosphate will be rewarded. Coating with soils, if possible, will be appreciated. (Meadow soil) : Drainage is required except types of hilly area. In order to keep applied nitrogen from its release from surface of the field in a free gas from, nitrogenous fertilizers must be applied as deep as they are kept in reduced condition. Of sandy soil kind, fertilization must be made separately in suitable seasons, lest it should cause the constituents to be leached away. Physiological decay of plant roots, occasionally cbserved, will be avoided by applying fertilizers of non-sulphuric acid radical. (Gray lowland soil) : Deep cultivation will be appreciated. Heavy application of farm yard manure is required. When used as a dry farm, the acid reaction of soil, expected to easily occur, must be neutralized. Among the types, listed in this report, this soil type may be considered to be the most profitable.
