A variety of organic feedstocks can be used for anaerobic digestion, resulting in digestates with diferent compositions, afecting the fertiliser value. Therefore, two experiments were conducted to assess (1) diferences in the nitrogen (N) fertiliser value of seven digestates from diferent feedstocks in a 2-year feld experiment with spring wheat, and (2) the degradability of organic matter (OM) in the digestates within an aerobic incubation experiment. In the feld, mineral fertiliser equivalents were in a range of 18–60% (1st year) and 39–83% (2nd year). Fertiliser properties could describe 58.9–74.2% of the N oftake variance among digestates. In the incubation experiment, digestates produced 720–1900 mg CO2-C kg−1. After 56 days, 61% of organic C added by food waste digestate has been mineralised, compared to 16–22% for the other digestates. Digestate composition (C/N, Corg/Norg, carbonate, cellulose, lignin, and crude fbre) could explain 90.4% of the CO2 evolution. In both experiments, digested food waste stood out among digestates with the highest N oftake and highest OM mineralisation. In conclusion, diferences in fertiliser value and OM degradability could be related to compositional variations. However, apart from food waste, the composition had only minor infuence on digestate performance after soil application.
Häfner F., Hartung J., Möller K.
Digestate Composition Afecting N Fertiliser Value and C Mineralisation.
Waste and Biomass Valorization, (13), 2022, 3445-3462.
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ISSN Print: 1877-2641
ISSN Online: 1877-265X
Digital Object Identifier (DOI): https://doi.org/10.1007/s12649-022-01723-y
Publikations-ID (Webcode): 49674
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