Rewetting dried soils for elucidating SOM dynamics in andic soils of a Japanese temperate forest

Nagano, Hirohiko*; Atarashi-Andoh, Mariko  ; Tanaka, Sota*; Hiradate, Shuntaro*; Fujii, Kazumichi*; Koarashi, Jun   

Rewetting dried soils is a crucial topic in soil organic matter (SOM) research from both viewpoints to evaluate the climate change impacts on SOM dynamics and the microbial utilization of soil organic substrate. Here, we present the substantial potential of rewetting dried soils in SOM research for Japanese andic soils. We introduce two studies investigating rewetting dried soils using Japanese andic soils: incubation of soils with dry-wet cycles and extraction of organic substrates with water. Dry-wet cycles stimulated soil CO release up to 50% more than the CO release under the continuously constant moisture condition. Water-extractable organic matter exhibited a contrast enrichment in the stable isotope signature under different substrate availability. The results indicate the substantial potential of rewetting dried soils for evaluating the climate change impacts on SOM dynamics and also the microbial utilization of soil organic substrates.