Effect of organic manure on biological activities of Cr-contaminated soil

Incubation experiment was carried out to study the effect of application of pig manure and rice straw on the biological activity of Cr-contaminated permeable paddy soil The results showed that soil biological activity declined significantly after contaminated by Cr. However, the application of organic manure made the content of chemical available Cr decreased significantly, the decreased percentage of which was about 30% while the content of soil microbial C,N and P and the activity of urease and catalase increased, ranging from 15% to 273%. There was negative correlation between chemical Cr and the content of soil microbial C,N, indicating that the content of microbial C,N could become an index of Cr-contaminated soil 