Effect of Different Fertilizers on Continuous Tobacco Cropping Rhizospheric Soil Microorganisms and Enzyme Activities

Problems caused by continuous tobacco cropping were critical obstacles restricting the yield and quality of tobacco leaf.The trial was conducted in a filed,where tobacco was continuously planted for 12 years.By applying different fertilizers,we studied the effect of different fertilizers on the yield,quality and rhizospheric soil microbial biomass,enzyme activity of the rhizosphere.The results indicated that different fertilization treatments had different effects on leaf yield,soil microorganism and enzyme activity in continuous cropping,and farmyard manure application was favorable to improve the leaf yield.The result of soil microbial biomass analysis showed that microbial biomass C and N,and microbial respiration intensity ranked as farmyard manureorganic fertilizernitrogen fertilizercompound fertilizer after different fertilizer treatments.Furthermore,the activity of neutral phosphatase,alkaline phosphatase,urease and sucrase in tobacco rhizospheric soil was the highest with application of organic fertilizer,and farmyard manure application had the highest acid phosphate activity.In addition,the activity of soil enzyme(polyphenol oxidase,peroxidase,catalase,dehydrogenase) involved in resistance ranked as farmyard manureorganic fertilizernitrogen fertilizer compound fertilizer.