Wakayama prefecture is, with Shizuoka prefecture, a chief destrict of citrus production in Japan. Author stiudied the soil profiles of citrus garden in this prefecture and obtained some analytical data with regard to their physical and chemical properties. The results are summarized as follows : 1. Soils showed various mechanical compositions with much gravel, sometimes, with 20〜50% and were classified into clay, clay loam, loam and sandyloam soil. 2. SiO_2-Al_2O_3 ratio of clay fraction was generally high. Some showed 2.5〜3 but others 4〜7. 3. Humus and nitrogen contents were commonly low. C-N ratio was mostly about 10,but some were exceptionally high. Available phosphoric acid was very low even in surface soil, while available potash was not so low as phosphoric acid. These contents of surface soils are given by following figures, and deeper horizons contain them much less. [table] 4. pH value was mostly 5.5〜4.5. Content of exchangeable base in surface soil was not sufficient and S value was 26.31〜4.30 m.e./100 g. Generally most part of bases consisted of magnesium greater than calcium and this relation was much in deeper horizon. Saturation degree of surface soil was not high, i.e., 34. 61〜14 68 5. From these results, the citrus garden soils in Wakayama prefecture may be classified into two groups which are in fair accordance with their geological formations.
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