Studies on the anaerobic decomposition of plant materials

Abstract

The relative rates of decomposition of rice straw in decreasing order were: aerobic, water-logged and anaerobic fermentations. Cellulose and lignin were more easily attacked under water-logged conditions than under anaerobic conditions. Partially aerobic resemble anaerobic conditions in the nature of the products obtained, but smaller amts. of organic acids and methane were formed and there was in increase in the amt. of CO2 evolved. Under conditions of mild aeration much more H was obtained than under anaerobic conditions. The N factor and N equivalent decreased in the order: aerobic (0.536; 1.11), waterlogged (0.395; 0.961) and anaerobic (0.069; 0.169) showing the degree of protein accumulation in the 3 cases. The protein formed under aerobic conditions was mostly insoluble in water; under water-logged conditions it remained in soln. In most respects the decomposition of rice straw under water-logged conditions gave results intermediate between aerobic and anaerobic decompositions.