soil fertility in unfertilized arable soils

Soil fertility, one of the most important soil functions, is strongly influenced by activities of microbial communities. However, it is not well clarified how community structure including richness, mass and composition influence soil fertility. We examined unfertilized arable soils in which the relationships between soil functions and microbe communities can be analyzed without fertilizer effects. Soils were sampled from 12 unfertilized arable farms extending over 1000 km in eastern part of Japan and soil properties including C turnover rate, N mineralization rate, microbe C and various soil chemical properties were measured. Soil bacterial and fungal communities were analyzed by pyrosequencing using 16s RNA and ITS regions. In addition, root microbial communities of maize raised in each soil were also investigated.