Effect of alfalfa(Lolium multiflorum L)on degradation of trichlorophenol in soil

The roles of alfalfa(Lolium multiflorum L ) on remediation of TCP contaminated soil, the growth of alfalfa were studied in a pot experiment. The results showed that TCP content in soil decreased with culture time during 75d culture period. Alfalfa promotes this decrease. 75 days pot experiment showed that the concentration of TCP in soil grown alfalfa was significantly lower than that without plant grown ( P <; 0. 05) .Under 1 ,10 and 100mg/ kg TCP treatments ,TCP biodegradability amounted to 55.2%, 80.2% and 90.1% respectively. While that of soil without plant growth were 20.1%, 30.2%, 49.2%, respectively. The activity of soil polyphenol oxidase, dehydrogenase and catalase are increasing in soil with plant grown and were obviously higher than those without plant growing (p <; 0.05), which improved soil degradation ability of soil microbial and plants. There is also inhibition of high contamination on enzyme. Though soil itself can biodegrade TCP, alfalfa could improve bioremediation role of TCP contaminated soil, thought enhance the degradation rate of TCP in soil and increase alfalfa yield and the microbial activity in rhizosphere soil.