Organic Matter Decomposition in Red Soil as Affected by Earthworms

摘要

The earthworms Pheretima carnosa, Drawida gisti and Eisenia foetida were studied to compare their rncontributions to the decomposition of various organic materials surface-applied on red soil in a 165-day rngreenhouse experiment. The native species Pheretima carnosa and Drawida gisti were equally effective in rnaccelerating the decomposition of maize residue, according to fresh body weight, while commercial species rnEisenia foetida had no significant influence on dry mass loss of maize residue. Liming with CaCO3 or CaO rnshowed little effect on maize residue breakdown involved by Pheretima carnosa, but it inhibited this process rninvolved by Drawida gisti. The capability of Pheretima carnosa to the decomposition of five kinds of organic rnmaterials was thoroughly examined. The dry mass losses in worm treatments were in the order of soybean rnresidue ＞ maize residue ＞ pig manure ＞ semi-decayed maize ＞ ryegrass. However, the relative contributions rnof the earthworm to dry mass loss were in the order of pig manure (89.8%) ＞ semi-decayed maize residue rn(49.1%) ＞ maize residue (29.4%) ＞ soybean residue (20.9%) ＞ ryegrass residue (16.5%). Pheretima carnosa rnconsumed 20～120 mg dry weight of organic material per gram fresh weight of biomass per day.