Aerated digestate management enhances soil properties, reduces greenhouse gas emissions, and shifts microbial communities.

Food-waste digestate contains valuable plant-available nutrients but is prone to reactive nitrogen losses and greenhouse gas (GHG) emissions upon land application. Aeration of digestate offers a simple strategy to capture carbon dioxide (CO2), nitrous oxide (N2O), and ammonia (NH3) released during processing while stabilising the liquid and reducing environmental risks when applied to soil. This study evaluated the effects of aeration on digestate stability and its subsequent impacts on soil nitrogen dynamics, GHG emissions, and microbial community responses. The agronomic and environmental performance of aerated digestate was assessed, with future work aimed at evaluating digestate composition and gas emissions during the aeration process. A soil incubation compared raw digestate (LD) with aerated liquid digestate (ALD), with gaseous emissions normalised to volatile solids (VS). Aeration reshaped nitrogen speciation and ionic strength, reducing NH4+-N from 3458 to 203 mg kg-1 and electrical conductivity from 16.7 to 6.7 mS cm-1 prior to soil application. In soil, ALD reduced cumulative N2O by ∼43 % relative to LD (0.0281 vs 0.0492 mg N2O g-1 VS), while cumulative CO2 per unit VS was comparable for both (∼300 mg CO2 g-1 VS). Both amendments increased soil NO3- over time, though LD produced the highest final concentration. ALD promoted nitrification without the elevated N2O associated with LD, indicating gradual mineralisation of organically bound N. Community profiling showed that LD initially suppressed diazotrophs and heterotrophic decomposers, with subsequent recovery of nitrate-reducing microbes (e.g., Neobacillus, Noviherbaspirillum), aligning with higher N2O yield. In contrast, ALD promoted a more gradually transition to a community dominated by aerobic polymer-degrading taxa (e.g., Aequorivita), indicative of reduced redox stress. Overall, aeration transformed LD into a biologically stable, low-emission amendment, improving soil function and sustainability of digestate management.