The change in chemical components of soil with time was examined under no artificial irrigation by means of lysimeters packed with soil taken from the reclaimed land of Iya. The soil was rich in fine particles(silty clay) and poor in the permeability of water, so that the desalting of the soil was siginficantly difficult. The soil had an abundance of oxi dizable sulfurs, which were oxidized by air with the elevation of atmospheric temperature to give sulfuric acid. The resulting acidific ation of the soil made the growth of crops very difficult.