Abstract
The culture of carp fry in rice field has successfully been carried out in those districts, such as Nozawa, Nagano prefecture and Koriyama, Nara prefecture. The cultivating method employed in Suginoki village, Nozawa especially attracts the auther's attention. It is charachterized in fertilizing the field with organic matter together with some quantity of inorganic nitrogen manure, suck as ammonium sulphate, previously before the cultivation of carp fry is carried out.
The result of the cultivation experiments shows that the employment of the inorganic nitrogen manure brings a better effect when it is used at the optimum ratio together with organic matter. But it is noticed that the inorganic matter must be employed in the earlier period before the cultivation of carp fry is carried out, for the harmful effect is often fourd if it is used in the later period when reductive reaction in water violently occurs owing to high temperature.
