Earthworms stimulate nitrogen transformation in an acidic soil under different Cd contamination.

摘要: Abstract In acidic Cd-contaminated soils, soil nitrogen conversion is inhibited and usually block supply for plants. Earthworms are well known improving properties regulating various biogeochemical processes including cycling. To figure out the effect mechanisms of earthworms on transformation in soil, ten treatments with without A. robustus five Cd concentration gradients were established. The tolerant to about 6 mg kg -1 . potential ammonia oxidation soils was very low, ranging from 0.05 0.1 µg NO 2 - -N g d Although AOA more abundant than AOB, by pollution, while AOB showed some increase under Cd-stress. may play a dominant role but recovery nitrification probably due AOB. significantly increased pH, DOC, ammonium PAO, thus promoted ammonification nitrification, had no significant net nitrification. Correlation analysis results demonstrate that promote PAO increasing NH 4 + content, abundance. This study could provide theoretical basis solving problem nitrogen-cycling-functional degradation process phytoremediation heavy metals-contaminated soils.