Standardisation of methods in soil microbiology: progress and challenges.

A plethora of methods have been developed over the few last decades to enable a better understanding of the ecology of soil microbial communities and their roles in soil functioning. However, there is generally considerable variation (both subtle and more extensive) in the actual realisation of these methods, and limited efforts have been devoted to their standardisation, despite this being crucial to underpin data comparison and integration. Ensuring comparable data across studies through standardisation is arguably best-practice, as well as necessary to effectively meet the objectives of various schemas, which require assessment of the consequences of the global change and intensification of human activities on the functioning of the soil ecosystem and its biological diversity. This article presents an overview of the existing and forthcoming ISO standards in soil microbiology and highlights possible future research efforts to be undertaken for developing new standards. We also discuss some practical and theoretical bottlenecks and hurdles that have limited standardisation in soil microbiology up to now.