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NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2023

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Birch wood is a potential feedstock for biogas production in Northern Europe; however, the lignocellulosic matrix is recalcitrant preventing efficient conversion to methane. To improve digestibility, birch wood was thermally pre-treated using steam explosion at 220 °C for 10 min. The steam-exploded birch wood (SEBW) was co-digested with cow manure for a period of 120 days in continuously fed CSTRs where the microbial community adapted to the SEBW feedstock. Changes in the microbial community were tracked by stable carbon isotopes- and 16S r RNA analyses. The results showed that the adapted microbial culture could increase methane production up to 365 mL/g VS day, which is higher than previously reported methane production from pre-treated SEBW. This study also revealed that the microbial adaptation significantly increased the tolerance of the microbial community against the inhibitors furfural and HMF which were formed during pre-treatment of birch. The results of the microbial analysis indicated that the relative amount of cellulosic hydrolytic microorganisms (e.g. Actinobacteriota and Fibrobacterota) increased and replaced syntrophic acetate bacteria (e.g. Cloacimonadota, Dethiobacteraceae, and Syntrophomonadaceae) as a function of time. Moreover, the stable carbon isotope analysis indicated that the acetoclastic pathway became the main route for methane production after long-term adaptation. The shift in methane production pathway and change in microbial community shows that for anaerobic digestion of SEBW, the hydrolysis step is important. Although acetoclastic methanogens became dominant after 120 days, a potential route for methane production could also be a direct electron transfer among Sedimentibacter and methanogen archaea.

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We conducted a study over four rice seasons to assess the effects of dairy manure application on water loss, nutrient leaching, and rice yield compared to chemical fertilization. Water input, soil water storage, water percolation, plant growth, and yield data were recorded under triplicate field lysimeters that received either chemical fertilizers or organic manure. The lysimeters received alternate wetting and drying irrigation (5-cm after 3 days (2018 Aman season), 6 days (2019 Boro and Aman seasons), and 9 days (2020 Boro season) of ponded water disappearance) in addition to rainfall (37.5, 33.1, 40.9, and 47.4 cm, respectively). Leachate and ponded water samples were analyzed for nitrogen (N) species (NH4+ - N and NO3− - N) and available phosphorus (P) content. Manure application increased soil water storage by 1.2–4.4 cm/m but did not affect percolation loss (44–64% of water input) in silt loam soil. The chemical fertilization had significantly higher leaching concentrations of nutrients (NO3− - N at 0.75–3.6 mg/L and P at 0.02–0.15 mg/L) in several leaching events in the last three seasons than the manure treatment (NO3− - N at 0.75–3.2 mg/L and P at 0–0.21 mg/L). Overall, the manure treatment reduced the leaching load of N and available P by 13% and 23.6%, respectively. The N and P concentrations in the topsoil were higher for the manure treatment. Manure application increased rice yield by 15% and water productivity by 0.07 kg/m3 by augmenting soil water availability during the drying cycles of alternate wetting and drying processes. In addition, recycling manure in soil significantly reduced its environmental pollution compared to other inappropriate disposal methods. However, research needs remain important to adjust manure management options.