成果の概要

Field observations were conducted at experimental sites in the central highlands and coastal regions of Madagascar to assess the impact of the phosphorus (P) dipping technique and other fertilizer management practices on rice yield and environmental impact. In the highlands, the effects of P-dipping on early rice growth were clearly visible compared to conventional farming practices. This effect was even more pronounced when P-dipping was combined with nitrogen (N) and potassium (K) fertilizers. Environmental parameters such as air samples, soil temperature, and other soil characteristics were recorded during these observations. In the coastal regions, preliminary trials were conducted at 20 farmers' fields across three villages using the P-dipping technique. The results indicated that the response of early rice growth to P-dipping varied depending on the soil types and field conditions in the region.