Abstract
(1) Surveying 22 villages in 9 areas of Hiroshima prefecture, we analysed ecologically the famers' technique about the ridge hilling in muddy fields by Japanese plow (suki).
(2) Such subjective intentions of farmers, as they determine the methods of ridge-hilling chiefly by the depth of soils, capacity of drawing animals, references to succeeding operations and areal customs, are carried out either directly or indirectly.
(3) The efficiency of ridge-hilling is determined directly by the capacity of drawing animals and the utilizing method of implements, and indirectly by the conditions belonging to areas, farm management and fields.
