節水型乾田直播導入による労働力削減効果に関する考察

water-saving upland direct seeding

北海道大学農經論叢

This study focuses onʠwater-saving dry direct seeding,ʡa rice cultivation method that is basically managed under non-flooded conditions throughout the growing season and eliminates water-management operations, and examines its labor-saving effects. Based on a field survey conducted in November-December 2025, we analyzed two case farms—Farm A in Kyowa Town and Farm B in Kutchan Town, Hokkaido—by organizing their objectives for adoption and the process of expansion and then comparing labor hours by operation item using the Hokkaido Agricultural Production Technology System (6th edition) as a benchmark. The results show that water-saving dry direct seeding can reduce total labor hours by about 80% compared with conventional transplanting and can also achieve labor savings relative to conventional dry and flooded direct-seeding systems. The main factors are the elimination of nursery raising and transplanting operations, together with the absence of water-management work associated with flooded-field management. Meanwhile, yields tend to be lower and more unstable than under conventional transplanting, indicating that technical challenges remain.