Abstract
The working efficiency and rice yield of large-scale paddies were investigated in a flat plane in Niigata. Large-scale paddies (40 a and 60 a) were created by removal of levees, without further mechanical land consolidation, and cv. Koshihikari was produced from May to September in 1998 and 1999. The newly created large-scale paddies were flat, as the standard deviation (SD) of ground height in the original paddies was within the standard level set by Ministry of Agriculture, Forestry and Fisheries. Transplantation of rice seedlings and irrigation were performed smoothly. The efficiency of human labor such as fertilizer application decreased in the large-scale paddies. On the other hand, the efficiency of mechanical work such as tillage, pudding and harvest increased and fuel consumption decreased clearly in the large-scale paddies. The direction in which the drain was made in the paddy did not affect the efficiency of irrigation during midseason drainage. There was not a significant difference in the rice yield among the 20 a, 40 a and 60 a-paddies.
