Decomposition of the water-soluble fraction of sudangrass residue in soil

Abstract

Ground sudangrass forage was extracted at room temperature with demineralized water. The insoluble residue, the water-soluble residue, unextracted sudangrass and the recombined soluble and insoluble fractions were incubated in remoistened, air-dried soil to measure the influence of the water-soluble fraction on net carbon dioxide evolution. The maximum rate of carbon dioxide evolution from the check soil and from any treatment containing the water-soluble fraction of sudangrass occurred about 14 hours after initiation of incubation. Maximum rate of carbon dioxide evolution from the soil treated with the insoluble residue occurred about 39 hours after initiation of the incubation. The rate of carbon dioxide evolution from the soil which received the water-soluble residue was not significantly different from the rate from the check soil after 44 hours of incubation.