Impact of biogas digestates on soil microbiota in agriculture: a review

International audienceThe global production of biogas has increased threefold during the last decade to partly replace fossil fuels, yet biogas production by anaerobic digestion generates substantial amounts of by-products named digestates. These biogas digestates can be recycled in soils to fertilize crops and to sequester carbon. Nonetheless, the impact of digestates on the soil biological is actually poorly known. Here, we reviewed the impact of digestates published in 56 articles reporting 23 microbial parameters. Half of the articles show neutral effects of biogas digestates and 7% showed negative effects. 25% of the articles show more stimulation of the soil microbial quality by biogas digestates, whereas 17% of the articles show less stimulation, compared to other organic fertilizers