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

厌氧消化在欧洲越来越多地用于处理有机基质和生产沼气作为可再生能源。残留物（消化物）在农业中用作有机肥料。该研究旨在评估在田间应用消化物对蚯蚓的短期（几小时）到长期（两年）的影响，并在实验室条件下调查氨和蚯蚓行为对消化物毒性的作用。短期。首先，我们研究了用消化物、牛粪或化肥施肥的田地中的蚯蚓群落两年。在第三年的受精事件之前和之后评估蚯蚓丰度。在施肥后立即评估土壤表面的蚯蚓死亡率。下一个，Aporrectodea caliginosa和Lumbricus terrestris在微观世界 (110 cm ³ ) 中进行测量，以更好地了解短期毒性（两周）。最后，我们将消化物 (40–80 t ha ^-1 )撒在土柱 (5300 cm ³ ) 上，并在两周后使用 X 射线断层扫描来评估蚯蚓在岩心中的挖洞行为。与用化肥处理的田地相比，用消化物或牛粪处理两年的田地中蚯蚓的丰度高出 150%。在液体消化物和牛粪撒布（18 到 24 吨公顷^-1）。两周内，消化物（10% 到 20%（新鲜消化物/干土））和氨对微观世界中的蚯蚓也是致命的。相比之下，在消化液扩散两周后，土柱内没有发生死亡；A. caliginosa避免了具有高消化物输入的土壤表面。该案例研究强调了消化物的潜在短期毒性（几个小时），从长期来看（从两周到两年），它在该领域的影响从中性到积极影响。需要进一步研究以了解不同固体和液体消化物对不同土壤中土壤大型动物的影响。