Effect Of The Legumes Soil Leaching Liquor On Microbial Community And Enzyme Activity In Continuous Cropping Potato Field

In order to ascertain the effect of the leguminous plants on continuous cropping potato soil microbial community and enzyme activity. The experiment uses potato cultivars ‘Xindaping’ as test material, The experiment choiced four years potato continuous cropping field soil leaching solution mixed with legumes(four years medicago sativa L.cv.Q ingshui) soil leaching liquor at t he ratio of 1:1, 1:2, 1:3, 1:4 and 1:5 to research the legumes soil leaching liquor on soil microbial community, enzyme activity and physico-chemical properties in continuous cropping potato field. Select the legumes and potato crop rotation system to overcome the potato continuous cropping obstacles and provide the theory basis for farmland sustainable development of the arid planting area. The main research conclusions are as follows:1. Substrate conductivity and PH showed a downward trend after the first rise in potato growing period. The ratio of 1:4 soil leaching liquor can significantly improve the potato substrate cation exchange capacity and orga nic matter content, meanwhile, it could decrease conductivity and PH of potato substrate. The ratio of 1 :3 soil leaching liquor increased the Avail.N content of the potato substrate. The ratio of 1:2 soil leaching liquor increased Avail.P and Avail.K content of potato.2. The legumes soil leaching liquor have a significant effect on soil enzyme activity. The ratio of 1:4 soil leaching liquor significantly improves catalase and alkaline phosphatase activity of the potato substrate. And also can promote the invertase and urease activity in potato tuber formation period and tuber mature period. The ratio of 1:3 soil leaching liquor greatly enhanced urease and invertase activity in potato tuber growth period.3. Legumes soil leaching liquor have a significant effect on soil microbial community. The ratio of 1:4 soil leaching liquor greatly increased anaerobic azotobacter, nitrifier and denitrifying bacteria quantity in potato growth period. At the same time increased the quantity of actinomycetes in potato tuber formation period. The ratio of 1:3 soil leaching liquor greatly increased bacteria, actinomycetes and aerobic azotobacter quantity in potato tuber growth period, while markedly inhibited fungi quantity in potato whole growth period. The ratio of 1:5 soil leaching liquor greatly increased denitrifying bacteria quantity in potato tuber formation period.4. Between the soil microorganism,enzyme activity and physico-chemical properties have some certain relativity. Bacteria and actinomycetes were extremely significant positive correlation. Fungi and other indicators have no significant correlation. Actinomycetes with four enzymes and nutrients showed a highly significant positive correlation. In nitrogen physiological group, except aerobic azotobacter with PH has a significant positive correlation, anaerobic azotobacter, nitrifier and denitrifying bacteria has a negative correlation. Catalase, urease, alkaline phosphatase and invertase with physico-chemical properties and (?) have significant correlation. Catalase, urease, alkaline phosphatase and invertase have significant positive correlation between each other.