Carbon mineralization in soil amended with different organic materials

Laboratory incubation experiments were conducted (for 21 days) to determine the rate and extent of decomposition of 3 animal wastes (farmyard manure, pig slurry and poultry manure), 2 urban wastes (sewage sludge and municipal refuse compost) and one crop residue (rye straw) in a sandy loam soil. The extent of amendment decomposition was found to be a power function of time, related to the incubation temperature and chemical composition of the organic material. The different rates of application used, revealed the pronounced effect of straw on loss of native soil carbon. Farmyard manure and municipal refuse compost were found to be the materials most resistant to short-term decomposition