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The Characteristics of Tea Soils (Part 8)

1964; Japan Epidemiological Association; Volume: 1964; Issue: 22 Linguagem: Inglês

10.5979/cha.1964.22_63

1883-941X

Sôgo KAWAI,

Agriculture, Soil, Plant Science

The nitrogenous characteristics of the tea soils derived from Fuji volcanic ash soil, Makinohara diluvial soils (red-yellow and "Kuroboku" soil) and Kakegawa tertiary soil were examined.The results were summarized as follows:1. The nitrogen content of ammonium form was much in the surface horizon in every soil and the nitrate content was relatively much in the 1st and 3rd horizons and little in the 2nd horizon. The content of both ammonium and nitrate was poor in the tea soil and the uncultivated soil and rich in the cultivated soil.2. The dry effect of soil in Fuji soil and Makinohara "Kuroboku" soil having large content of humus was higher than that of Makinohara red-yellow soil and Kakegawa soil and it was higher in the tea soil and the uncueltivated soil than in the cultivated soil.Generally, it was high in the surface horizon and low in the under horizon in every soil.3. The absorption of ammonium by these soils was different with the kind of ammonium salt supplied and in every soil, the order of absorption of ammonium salt was as follows: amm. phosphate>amm. carbonate>amm. sulphate>amm. chloride. The absorbed quantity of ammonium from amm. phosphate and amm. carbonate was comparatively high in Fuji soil and Makinohara "Kuroboku" soil but that from amm. sulphate and amm. chloride was rather high in Makinohara red-yellow soil and Kakegawa soil. The cultivated soil absorbed every ammonium salt easier than the tea soil and the uncultivated soil.4. The order of ammonification degree of these soils was as follows: Fuji soil>Kakegawa soil> Makinohara "Kuroboku"soil>Makinohara red-yellow soil after 2 days, but its degree was almost equal in every soil after one week. Generally, it was weaker in the tea soil than in the uncultivated and cultivated soil, and in every soil, its degree increased with the addition of calcium in the soil.5. The nitrification was generally weak in soil, especially in Kakegawa soil. Among the every three kinds of soil, it was stronger in the cultivated soil than in the other two and it slightly increased with the addition of calcium in the soil.