Abstract

These studies were carried out to investigate the effects of rice straw on microflora in relation to the decomposition of organic matter, and the rate of rice straw decomposition. The number of total bacteria was increased in the first stage, and the number of microorganisms in upper layer was generally larger than lower layer. The number of fungi tended to decline as rice plant grew. Aerobacter among cellulose decomposition bacteria decreased with time, and the number of microorganisms in lower layer was higher than upper layer. The number of glucose decomposition bacteria and sulfate reducing bacteria increased in the submerged soil to which rice straw was applied, but decreased by percolation. the change of manganese oxidizing bacteria seemed not to be affected by rice straw application while they tend to increase as the rice plant grew. The aspect of microorganisms in the percolated water was same that of lower layer, but the number was low as much $10^{-1}$ during the whole stages. The decomposition rate of rice straw applied to submerged soil was about 40 per cent during the rice grew. The decomposition rate of cellulose contained rice straw was about 30 per cent, and lignin was about 60 per cent. The 70-80 per cent of nitrogen remained in the rice straw applied to soil.

Keywords

File

Download PDF