Influence of Cow Manure Vermicompost on Plant Growth and Microbes in Rhizosphere on Iron Tailing

Effects of cow manure vermicompost on plant growth and microbial populations in rhizosphere of two species, white clover and alfalfa, were evaluated as they were added into iron tailing under greenhouse conditions. Germination rate, survival rate, height, fresh weight, dry weight and microbial populations in rhizosphere of 20-old-day seedlings of two species were analyzed under four concentrations, as 0% (control), 5%, 10%, 20% by volume, of cow manure vermicompost(CMV) in iron tailing. White clover and alfalfa had different responses to cow manure vermicompost under four concentrations as grown in iron tailing. The germination rate of white clover grown in 20% cow manure vermicompost was significantly more than that of grown in iron tailing with 5%, 10% cow manure vermicompost and iron tailing control(0%). The survival rates of white clover grown in iron tailing with 5%, 10% and 20% cow manure vermicompost were 40%, 48% and 53% higher than that of grown in iron tailing control(0%), respectively. The height of white clover grown in vermicompost was significantly greater than that of control, and the more vermicompost the higher plant height. The shoot weight of white clover including fresh and dry weight with vermicompost was significantly greater than those of control. Their dry weights of root with 10% and 20% vermicompost were greater than that in control. As to alfalfa, the germination rate in 10% vermicompost was greater than that of control. The germination rate with 20% vermicompost was significantly less than that in control. There was no significantly different in survival rate of alfalfa grown in vermicompost than of control. The heights of alfalfa with 10% and 20% vermicompost were shorter than that of control. The shoot fresh weight of alfalfa grown in 20% vermicompost was more than that of control. While their fresh weight of root with 10% vermicompost was less than that of control. The two species, both white clover and alfalfa, can stimulate the micro- bes in rhizosphere, and the more cow manure vermicompost, the more cultural bacteria and actinomyces in rhizosphere of plants grown in iron tailing. It can be concluded that the cow vermicompost can significantly promote plant growth(especially white clover) and improve the microbial environment in rhizosphere of two species as they were applied in iron tailing restoration.