1. Graduate School of Agricultural Science; Tohoku University; Sendai Japan
2. Central Region Agricultural Research Center; NARO; Tsukuba Japan
3. Faculty of Agriculture; Yamagata University; Tsuruoka Japan
4. International Nature Farming Research Center; Matsumoto Japan
5. Toyama Prefectural Agricultural, Forestry and Fisheries Research Center; Toyama Japan
6. Tokyo University of Agriculture; Tokyo Japan