Status and changes of the properties of cultivated soil in Yamagata prefecture [Japan]
2006
Nagasawa, K.(Yamagata-ken. General Agricultural Research Center (Japan)) | Kumagai, K. | Nakagawa, F. | Sato, Y. | Konno, Y. | Morioka, M. | Ueno, M. | Yamaguchi, K.
Status and changes of the properties of cultivated soil in Yamagata Prefecture were analyzed from the result soil environment basic research (1979-1998) and soil function monitoring research (1999-2003). 1. In the paddy field, cation exchange capacity, availability silicic acid content, availability phosphoric acid content tended to be decreased. Especially, since the decrease of the availability silicic acid content was big. Compactness of soil tended to be decreased. 67% of the paddy field showed the tendency in the wet paddy, and 10% of that tended to become well-drained. 2. In the upland field, electric conductivity, cation exchange capacity, exchangeability calcium content and availability phosphoric acid content tended to be increased. The compactness of the plow layer tended to be decreased, and that of the plowsole layer tended to be increased 3. In the field under perennial crop, electric conductivity, cation exchange capacity, exchangeable potassium content and availability phosphoric acid content tended to be increased, and exchangeability magnesium content tended to be decreased. Compactness of soil tended to be increased. Still, depth of the soil layer tended to be increased in all classification of land category.
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