Abstract
Complimentary to the results reported in Part 3,4 was studied the effect of oxido-reductive power of the growing rice plants on the leaching down of soluble organic matter in the soil leachate as revealed by acid-permanganate consumption. As shown in Table 1,2 and Fig 1,2,3,4,the increase of the leached organic matter in the planted plots as against to the not-planted in the later half period of rice growth was out-standing in the soil of the degraded type (Hiroshima soil) in combination with the application of the sulfate-fertilizers. In the normal (Tamagawa soil) or well buffered (Tanashi soil) the effect was far less. Generally concluded, the leaching down of organic matter from the waterlogged soil should be apprehended on the dynamic interaction of the nature of the soil, kind of fertilizers applied and of the root activity, particularly its oxido-reductive power.
