DEVELOPMENT OF MOVIES AS THE TEACHING TOOL ON THE MOVEMENT OF IRRIGATION WATER IN PADDY FIELDS MANAGED UNDER VARIOUS CULTIVATION METHODS

Abstract

Hokkaido, the northern most of the four major islands of Japan, is an important rice-producing area. In Hokkaido there are some areas where the numbers of farm households are decreasing and the management scale for one farm household is increasing. In such areas, labor shortage occurs if only the conventional transplant cultivation is used. The necessity for introducing direct-seeding cultivation method has been increasing because by using this method it is possible to save labor. In some of the areas with increasing number of large-scale farm management, the farms employ large lot paddy fields and install underground irrigation facilities, which are useful in direct-seeding cultivation, to improve work efficiency. It is thought that it requires 2 to 3 years for the farmers to learn to effectively use the underground irrigation facilities because use of such facilities is a new experience for many farmers. The authors conducted observation of the groundwater level and depth of ponding in the paddy fields where the above-mentioned improvements were done, and made a movie using the obtained data. The movie is also useful for the authors in understanding the inflow and outflow of the groundwater, which are phenomena occurring underground. At a meeting of local farmers, the authors explained the movement of irrigation water by using this movie. The authors expect that the explanation using the movie will promote the farmers' understanding in effectively using the underground irrigation facilities.