Short- and long-term impacts of anaerobic digestate spreading on earthworms in cropped soils

Anaerobic digestion is increasingly used in Europe to treat organic substrates and produce biogas as a renewable energy source. The residual matter (digestate) agriculture an fertilizer. study aims at assessing the impact of digestate application field on earthworms from short term (few hours) long (two years), investigating under laboratory conditions role ammonia earthworm behavior toxicity term. First, we studied communities fields fertilized with digestates, cattle effluents, or chemical fertilizers for two years. Earthworm abundance was assessed before after fertilization event third year. mortality soil surface also immediately fertilization. Next, solutions Aporrectodea caliginosa Lumbricus terrestris measured microcosms (110 cm3) better understand short-term weeks). Finally, spread (40–80 t ha−1) columns (5300 X-ray tomography weeks assess burrowing cores. 150% higher treated years digestates effluents compared fertilizers. 0.5 2% adult died few hours liquid slurry spreading (18 24 ha−1). (10% 20% (fresh digestate/dry soil)) were lethal within weeks. In contrast, no occurred inside spreading; A. avoided high inputs. This case highlighted potential (a hours), which evolved towards neutral positive longer (from years). Further research needed diverse solid macrofauna different soils.