Abstract
N, P and K input into paddy fields from irrigation water in Fukuoka Prefecture were estimated from the data of N, P and K content in irrigation water X reported amount of irrigation water. Total N input was 21-30 kg/ha. The variation among regions was large and total N input in Chikugo was larger than in other regions. Total N input after booting was 10 kg/ha. Inorganic N input throughout the cultivation period was 11-15 kg/ha and that after booting was 5 kg/ha. Input of total P throughout the cultivation period was 1.5-2.2 kg/ha and that of P04-P was 0.8-1.2 kg/ha. K input was 29-42 kg/ha.
