Decomposition dynamics of plant residues in natural meadow in northeast China

Results of decomposition experiment applying plant residues in natural meadow in northeast China showed that there were the same change trends. The decomposition speed of plant residues was higher during earlier stage after applied, and lower during later stage. But there were significant differences among the residual organic carbon of plant residues. The residual organic carbon of Leymus chinensis residues was higher than that of Melilotus Suavedens residues. as far as the effects of different parts of plant residues on the residual organic carbon ,the root had it higher than the stem and the leaf, and the stem had it higher than the leaf. Experimental results also showed that buried depth of plant residues had effects on residual organic carbon. The residual organic carbon of plant residues buried 7 cm in depth was highest, and that of plant residues buried 15 cm in depth the second, and that of plant residues buried 0 cm in depth the lowest. Therefore, the root and stem of plant are advantageous to the accumulation of soil organic matter (SOM) while the leaf is advantageous to the nutrient releasing into hte soil. And deep root can help accumulate SOM.