Development And Evaluation Of Compound Microbial Fertilizers

Compound microbial fertilizer plays an important role in achieving ecological and economic gain in agricultural activities.In this study,based on the optimum proportion of the screening rhizobium,phosphate-solubilizing bacteria and potassium-solubilizing bacteria,and coordinated with growth activator,the suitable condition for multi-strain growth under mixed incubation was clarified.Furthermore,the activity and efficacy of mixed strains was identified by testing solubility and fertilizer efficiency of compound strains to lay the foundation for making the compound microbial fertilizer with high quality and efficiency.The main results were listed as follows:1)Based on antagonistic experiment,the rhizobium,the phosphate-and potassium-solubilizing bacteria could be mix-incubated.The highest growing quantity of multi-strains was found when the ratio of rhizobium,phosphate-and potassium-solubilizing bacteria is 1:1:1.In addition,the rhizobium and potassium bacteria under mixed incubation were 21.85% and 35.4% more than those under single incubation,respectively,indicating the synergistic effects existed among strains.2)The results of optimized incubating conditions for mixed stains indicated that the suitable conditions for compound strain growth were identified as the ratio of peptone,soybean powder and ammonium sulfate up to 4:3:3,meanwhile the sucrose and starch were more suitable for the culture of compound strains.When temperature was 33?,the pH of the original mixed fluid medium was 7.2,incubation period was 72 h and the dosage of growing activator was 3.5‰,the concentrations of rhizobium,phosphate-solubilizing bacteria and potassium bacteria in compound strains could reach to 2.27×107 /ml?0.89×109 /ml?1.93×109 /ml.The phosphate and potassium solubilizing rates could be improved to 9.10% and 9.74%,respectively.3)Application of the vinasse fertilizer could significantly increase the soil enzyme activity.The combination of vinasse fertilizer and inorganic fertilizer could increase 4.2% and 25.5% of soil urease activity than application of vinasse fertilizer or inorganic fertilize alone,respectively.4)Under equal nitrogen applied condition,the concentrations of total nitrogen and alkali-hydrolyable nitrogen in the soil with combined application of vinasse fertilizer and inorganic fertilizer together were increased by 9.8% and 11.6% compared with only applied vinasse fertilizer during the heading stage of Chinese cabbage,and contents of soil available phosphorus and rapidly available potassium were increased continuously in the treatment with vinasse fertilizer plus inorganic fertilizer.Moreover,soil organic matter content was also significant enhanced.5)Application of compound microbial fertilizer could significantly increase the population of nitrogen-fixing bacteria,phosphate-and potassium-solubilizing bacteria in the soils.Compared with application of vinasse fertilizer alone,the population of organic phosphorus solubilizing bacteria and phosphate solubilizing bacteria could be increased by 11.5% and 25.9% after combined application of vinasse and inorganic fertilizer.6)Compared with application of inorganic fertilizer alone,although the yield of Chinese cabbage was not significant differed with combined application of vinasse and inorganic fertilizer,but the quality of Chinese cabbage was obviously enhanced.Thus,the compound microbial fertilizer could not only sustain the yield of Chinese cabbage,but also improve the quality of the Chinese cabbage,which has the great agronomic and economic functions.