CHANGES OF MICROBIAL AND NEMATODES COMMUNITY STRUCTURES IN SWEETPOTATO (IPOMOEA BATATAS) CULTIVATION SOILS SUPPLEMENTED WITH NIGHT SOIL SLUDGE COMPOST

Abstract

 In this study, to attempt a development of nematodes control method without chemical pesticide for sweetpotato production field, we evaluated Bacillales and free-living nematodes predominated night soil sludge compost application from the aspect of microbial and nematodes community structure changes by DNA sequence analysis, quantitative PCR of parasitic nematodes, and discrimination of nematodes species. As a result of microbial community analysis based on 16S rRNA genes sequence, detection rates of phylotypes belonging to orders Bacillales and Actinomycetales increased in night soil sludge compost fertilized test areas. The result of 18S rRNA genes sequence analysis, ominivorous nematodes of order Dorylaimida were specifically detected in pesticide area and the compost fertilized areas. Besides, approximately 2-fold number of free-living nematodes was observed in the compost fertilized area using Baermann Funnel method compared with control areas. These results suggest that the Bacillales and free-living nematodes predominated night soil sludge compost can be improved microbial and nematodes community structures in sweetpotato cultivation soils.