Studies on organic acids in paddy field soils with reference to their inhibitory effects on the growth of rice plants

Summary It has been widely considered that organic acids accumulated in the soils of the illdrained humic paddy fields and of the fields with heavy application of green manures cause the root damage of plants in early and midsummer. To give an exmaple, Shimizu (1) reported recently that the preventive effects to paddy rice grown in the peaty soils of marsh-reed origin were derived from the remarkable production of volatile organic acids in the soil.