Abstract
Through the examination of the relation between soil maps and the map of crop productivity classes, the authours tried to clarify by means of what pedology would be able to contribute to the productivity. The results obtained were summarized as follows: 1. As the whole soil types, the significant correlation (-0.8298***) were recognized between the crop productivity and the altitudes. The reason for this phenomena would be considered as that in higher altitude zone there distributed the lower productive soils such as Brown forest soil and Pseudogley soil, while in lower altitude zone there located higher productive soil such as Lowland soil. 2. Within the same soil type (e. g. Brown volcanic ash soil), there were further high significant correlation (-0.9271***) between the productivity and the altitudes. The reason would be considered that the productivity would be affected with the cumulative temperature during cropping season, which also has the high significant correlation with the altitudes. 3. The crop productivity levels differ according to soil types under even the same climatic conditions. The reason would be that the soils are affected by the climatic factors such as air temperature, rainfall or others differently in accordance with the soil characters by which the soil types are classified. 4. As for as factors of the soil productivity are concerned, it should be very important to grasp accurately how the soils are affected by the climatic factors in situ, and how the soils reflect the affection of the climate on crop growth and yield. Through the way aforesaid pedology should further contribute to crop productivity than it does now.
