Nitrous oxide emissions and nitrogen use efficiency of manure and digestates applied to spring barley

摘要: Abstract Digestates produced by anaerobic treatment of manure and organic wastes for biogas production are rich in nutrients which should be recycled to agricultural land sustain crop growth. However, digestate properties highly variable, complicating the prediction agronomic value environmental impact. The objective this study was assess nitrous oxide (N2O) emissions nitrogen use efficiency during growth spring barley (Hordeum vulgare L.) when fertilized with digestates untreated manure, relate emission patterns soil materials. Experimental treatments received 100 kg NH4+-N ha−1 either pig slurry (PS), cattle (CS), a slurry-based from Maabjerg Bioenergy (MBD), or mixed digested dewatered sewage sludge (CS + DDS). Ammonium sulfate (MIN) unfertilized (Ctrl) served as references. Cumulative N2O-N at harvest ranged 0.02 1.97 kg ha−1, net corresponded 0.10–0.41% total N input. According graphical model N2O were related NO3−, rather than NH4+ availability, indicating that denitrification main source N2O. When observations fitted an empirical cumulated emissions, nitrification hotspots identified driver but low NO3− availability suggested role indirect, via coupled nitrification-denitrification. Yield-scaled 0.04 0.39 g N2O-N kg−1 grain yield. intensity MBD lower similar mineral fertilizer. In contrast, CS + DDS containing also material had highest yield-scaled emissions. Thus, performance can not predicted management, must take specific into account.