The combined analyses of microbial biomass and residue formation of both fungi and bacteria are rare in agro-ecosystem studies. This book provides profound knowledge on the effects of tillage, grassland conversion intensities and fertilisation on microbial biomass, residues and community structure across different on-farm trials in Germany.Chapter 1 deals with the microbial turnover of SOM, emphasizing microbial community and the effects of different tillage intensities. In chapter 2, we are offering a first attempt to study the effects of one-season tillage on stocks of microbial biomass and residues of a temperate grassland soil in both short and long-term. Chapter 3 quantifies the effects of land use change by combining CLPP with soil microbial biomass and residue indices as ecological indicators. It suggests the use of microbial biomass C/S ratio as an indicator for a shift in microbial community. This book features in-depth discussions on the strong relationships between microbial biomass and residue indices and points to the importance of saprotrophic fungi and biotrophic AMF for agricultural management induced effects on microbial turnover and ecosystem C sequestration.