Impacts of soil storage on microbial parameters

Abstract. This review aims to determine the impact of soil storage on microbial parameters (abundance/biomass, activity and various diversity metrics). We analysed the literature dealing with the impact of storage practices (cold, freeze, dry, freeze-dry and ambient storage) on soil microbial parameters. A total of 73 articles were included in the analysis, representing 261 basic data (impact of a given storage practice on a microbial parameter). Globally, 74 % of these data showed significant impact of storage on the measured microbial parameters, as compared to those measured on fresh, non-stored soil samples. The storage practices showed various effects on the soil microbial parameters, with sometimes opposite effects across different soil types. For instance, various soil enzyme activities did not respond the same way to storage practices, even in a given soil type. There are currently too few studies to draw recommendations, but some studies suggest that the pedoclimatic context could be useful for choosing the best storage option, with soils that regularly undergo drought or freezing being less impacted by dry and freeze storage, respectively. I conclude that storage practices for soil samples, when unavoidable, should be carefully selected according to conditions that prevail in the native soil environment, to microbial parameters that are analysed (even though there is no consensus for a best practice), and with different storage practices for different microbial parameters if necessary.