Microbial Carbonisation and its potential for on-farm composting
The search for agronomic solutions to the decline of soil health, open-ended nutrient cycles and greenhouse gas (GHG) emissions from agriculture, against the background of impending climate change, were motivations for this thesis. A composting trial on a Swedish farm was designed to find answers...
| Autor principal: | |
|---|---|
| Formato: | Second cycle, A2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2022
|
| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/17641/ |
| _version_ | 1855572928950697984 |
|---|---|
| author | Stephan, Ludwig Peter |
| author_browse | Stephan, Ludwig Peter |
| author_facet | Stephan, Ludwig Peter |
| author_sort | Stephan, Ludwig Peter |
| collection | Epsilon Archive for Student Projects |
| description | The search for agronomic solutions to the decline of soil health, open-ended
nutrient cycles and greenhouse gas (GHG) emissions from agriculture, against
the background of impending climate change, were motivations for this thesis.
A composting trial on a Swedish farm was designed to find answers to the
overarching research question of how feasible and climate-friendly on-farm
composting using Microbial Carbonisation (MC) is, compared to conventional
windrow composting (CC). MC can be understood as the biological
transformation of biomass under mesophilic and anoxic conditions, in contrast
to CC, which is an aerobic and partly thermophilic decomposition process.
The investigation of the MC method was approached using natural and
social science methodologies. Field trials were carried out, accompanied by
substrate, soil, emission and pore-gas measurements, as well as records of
machinery use. In addition, interviews were conducted with farmers already
using MC in Germany, to gain a better insight into its practical application and
farmers’ needs.
The results suggest that MC substrates can be richer in nitrogen (N) and
carbon (C) after composting than CC. The machinery requirement of MC was
only one tenth of the more labour-intensive CC process, which is associated
with lower fossil emissions. A novelty of the present research was that nitrous
oxide (N2O) emissions were measured for the first time on a MC compost.
Overall, on a weight basis, MC showed 30 – 40 % lower GHG emissions
during composting, compared to CC. This advantage, however, was offset by
28 – 40 % higher emissions in the field on an area basis. In addition, GHG
balances are highly dependent on the appropriateness of the measurementmethodology,
the period under consideration and the reference unit in which
the emissions are expressed. As CC showed higher N-losses during the
composting process, MC overall emitted 5 – 29 % less GHG per kg N applied
to the field. It was therefore not entirely clear whether MC or CC performed
better in terms of GHG emissions.
As MC can provide N- and C-rich substrates in a cost-efficient way, it
appears promising for the use in regenerative agriculture. The farmers’
interviews supported the results of MC being cost-efficient and practicable for
on-farm composting. Nevertheless, the field application of compost can
substantially increase the GHG balance of what at first sight appears to be a
climate friendly composting process. Future studies need to further address
this issue, as well as the impact of MC substrates on soil health. |
| format | Second cycle, A2E |
| id | RepoSLU17641 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2022 |
| publishDateSort | 2022 |
| record_format | eprints |
| spelling | RepoSLU176412022-04-01T04:00:41Z https://stud.epsilon.slu.se/17641/ Microbial Carbonisation and its potential for on-farm composting Stephan, Ludwig Peter Nature conservation and land resources Soil biology The search for agronomic solutions to the decline of soil health, open-ended nutrient cycles and greenhouse gas (GHG) emissions from agriculture, against the background of impending climate change, were motivations for this thesis. A composting trial on a Swedish farm was designed to find answers to the overarching research question of how feasible and climate-friendly on-farm composting using Microbial Carbonisation (MC) is, compared to conventional windrow composting (CC). MC can be understood as the biological transformation of biomass under mesophilic and anoxic conditions, in contrast to CC, which is an aerobic and partly thermophilic decomposition process. The investigation of the MC method was approached using natural and social science methodologies. Field trials were carried out, accompanied by substrate, soil, emission and pore-gas measurements, as well as records of machinery use. In addition, interviews were conducted with farmers already using MC in Germany, to gain a better insight into its practical application and farmers’ needs. The results suggest that MC substrates can be richer in nitrogen (N) and carbon (C) after composting than CC. The machinery requirement of MC was only one tenth of the more labour-intensive CC process, which is associated with lower fossil emissions. A novelty of the present research was that nitrous oxide (N2O) emissions were measured for the first time on a MC compost. Overall, on a weight basis, MC showed 30 – 40 % lower GHG emissions during composting, compared to CC. This advantage, however, was offset by 28 – 40 % higher emissions in the field on an area basis. In addition, GHG balances are highly dependent on the appropriateness of the measurementmethodology, the period under consideration and the reference unit in which the emissions are expressed. As CC showed higher N-losses during the composting process, MC overall emitted 5 – 29 % less GHG per kg N applied to the field. It was therefore not entirely clear whether MC or CC performed better in terms of GHG emissions. As MC can provide N- and C-rich substrates in a cost-efficient way, it appears promising for the use in regenerative agriculture. The farmers’ interviews supported the results of MC being cost-efficient and practicable for on-farm composting. Nevertheless, the field application of compost can substantially increase the GHG balance of what at first sight appears to be a climate friendly composting process. Future studies need to further address this issue, as well as the impact of MC substrates on soil health. Die Suche nach ackerbaulichen Lösungen für die Abnahme der Bodengesundheit, offene Nährstoffkreisläufe sowie Treibhausgasemissionen (THG) der Landwirtschaft, vor dem Hintergrund des drohenden Klimawandels, waren Motivation für diese Studie. Ein Kompostierungsversuch auf einem schwedischen Landwirtschaftsbetrieb sollte Antworten auf die übergeordnete Forschungsfrage liefern, wie praktikabel und klimafreundlich landwirtschaftliche Kompostierung mittels Mikrobieller Carbonisierung (MC) im Vergleich zur konventionellen Kompostierung (CC) ist. MC kann als biologische Umwandlung von Biomasse unter mesophilen und anoxischen Bedingungen verstanden werden, im Gegensatz zu CC, welchem ein aerober und teilweise thermophiler Abbauprozess zugrunde liegt. Die MC-Methode wurde mithilfe natur- und sozialwissenschaftlicher Methoden untersucht. Es wurden Feldversuche durchgeführt, begleitet von Substrat-, Boden-, Emissions- und Porengas-Messungen, sowie Aufzeichnungen des Maschineneinsatzes. Darüber hinaus wurden Interviews mit Landwirten geführt, welche MC in Deutschland bereits anwenden, um einen besseren Einblick in die praktische Anwendung und die Bedürfnisse der Landwirte zu erhalten. Die Ergebnisse deuten darauf hin, dass MC-Substrate nach der Kompostierung reicher an Stickstoff (N) und Kohlenstoff (C) als CC-Substrate sein können. Der Maschinenbedarf für MC betrug nur ein Zehntel von CC, was mit geringeren fossilen Emissionen einhergeht. Ein Novum war, dass zum ersten Mal Lachgas-Emissionen (N2O) von MC gemessen wurden. Insgesamt waren die THG-Emissionen bei MC während der Kompostierung pro Tonne Kompost um 30 — 40 % niedriger als bei CC. Dieser Vorteil wurde jedoch durch 28 – 40 % höhere Emissionen (pro Hektar) auf dem Feld wieder ausgeglichen. THG-Bilanzen sind in hohem Maße von der Messmethodik, dem betrachteten Zeitraum und der Bezugseinheit abhängig, in der die Emissionen ausgedrückt werden. Da CC während der Kompostierung höhere N-Verluste aufwies, emittierte MC insgesamt 5 – 29 % weniger THG pro auf dem Feld ausgebrachtem kg N. Es war daher nicht eindeutig, ob MC oder CC in Bezug auf die THG-Emissionen besser abschnitt. Wie auch durch die Interviews bestätigt wurde, liefert MC auf kosteneffiziente Weise N- und C-reiche Substrate und erscheint damit vielversprechend für den Einsatz in der regenerativen Landwirtschaft. Da die Ausbringung des Komposts jedoch die THG-Bilanz eines auf den ersten Blick klimafreundlichen Prozesses deutlich erhöhen kann, sollten künftige Studien sich mit dieser Problematik sowie mit den Auswirkungen von MC-Substraten auf die Bodengesundheit näher befassen. 2022-03-30 Second cycle, A2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/17641/3/stephan-l-20220331.pdf Stephan, Ludwig Peter, 2022. Microbial Carbonisation and its potential for on-farm composting : exploring reductive composting as an approach for regenerative agriculture. Second cycle, A2E. Alnarp: (LTJ, LTV) > Dept. of Biosystems and Technology (from 130101) <https://stud.epsilon.slu.se/view/divisions/OID-643.html> urn:nbn:se:slu:epsilon-s-17641 eng |
| spellingShingle | Nature conservation and land resources Soil biology Stephan, Ludwig Peter Microbial Carbonisation and its potential for on-farm composting |
| title | Microbial Carbonisation and its potential for on-farm composting |
| title_full | Microbial Carbonisation and its potential for on-farm composting |
| title_fullStr | Microbial Carbonisation and its potential for on-farm composting |
| title_full_unstemmed | Microbial Carbonisation and its potential for on-farm composting |
| title_short | Microbial Carbonisation and its potential for on-farm composting |
| title_sort | microbial carbonisation and its potential for on-farm composting |
| topic | Nature conservation and land resources Soil biology |
| url | https://stud.epsilon.slu.se/17641/ https://stud.epsilon.slu.se/17641/ |