Effects of bio-organic fertilizers application on the growth promotion，disease preventionandthe soil microflora of gravel-covered watermelon

In this study，Fusarium wiltofgravel-covered watermelon was taken as thetarget object. Through dilution-plate semar，Biolog-ECO micro-plate methodand field experimentin hole application，we studied the effects of bio-organic fertilizer application on the growth promotion，disease prevention and the effects on soil microflora， the functional diversity of soil microbial community. The results showed that using different amount of biological organic fertilizer application on gravel-covered watermelon plant in per hole point had a growth promotion effect. The effect of prevention control of Fusarium wilt and yieldgoes also obviously. The control effect reached more than 77% and the growth rate of yield was above 15%. Besides，bio-organic fertilizer application can change the soil microflora，increase the number of Bacteria and Actinomycetes in watermelon root and decrease amount of Fusarium oxysporum（pathogens）. And the number of Fungi decreased a little before increased slowly. Still，the soil microbial community improved their ability of using carbon resources and speed of metabolic activity. Functional diversity of soil microbialcommunity has something in different. The application of matrix 200 g alone had a certain effect on the growth of gravel-covered watermelon plants. However，the disease controlling effect was worse than that of bio-organic fertilizer 100 g because its main function of matrix was to loosen the soil. In general，the application of bio-organic fertilizer can significantly promote the growth of gravel-covered watermelon plants，effectively reduce Fusarium wilt of watermelon and drive soil microfloraof a beneficial direction.