Abstract
In this study, we investigated the management of irrigation and paddy fields in the Fukuoka-zeki land improvement district of Ibaraki Prefecture, which is predominantly a rice paddy area managed by part-time farmers. The following points were clarified: 1) In branch canals with many beneficiary farmers, farmers keep the division works of branch canals in an open state and adjust the amount of intake water at the inlet of each paddy or the division work of tributary canals. 2) In the middle section of the main canal, farmers hasten the start of water intake for puddling to avoid conflicts with the upper section farmers. 3) The working dates of puddling and rice transplanting were fixed annually. On the other hand, harvesting was done in according to the rice growth because a lot of part-time farmers outsource the harvesting work. 4) In an area dominated by rice paddies managed by part-time farmers, there are many beneficiary farmers along each branch canal and most of them are absent during the day. Therefore, it is difficult to operate the division work of the branch canal depending on water demand. Thus, the delivery water requirement tends to increase.
