Studies on the Nutrition of the Rice Plant with Reference to the Occurrence of the So-called "Akagare" Disease. : II. Influence of the Supply of Organic Acid and Hydrogen Sulphide to the Soil upon the Occurrence of the Disease.

The occurrence of "Akagare" disease of rice plants was tested by pot experiments using paddy soil on which the disease habitually occurs. Want of potassium and suppling butyric acid and hydrogen sulphide to the soil promoted the occurrence of the disease, but drainage of water about 3cm a day decreased its occurrence. The occurrence of the disease appeared to be highly correlative to the lowering of Eh value of plant and soil, to the increase in soluble-N content and soluble-N/protein-N ratio and to the root-rot.