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Data from a long-term field experiment in Norway, comparing digested and undigested slurry from organically managed dairy cows since 2011. The dataset includes chemical analyses of digested and non-digested slurry, soil characteristics at plot level of pH, extractable nutrients, loss on ignition; crop yields and botanical composition. These data supplement the findings presented and discussed in the research article Anaerobic digestion of animal manure – long-term effects on crop yields and soil characteristics.

Untersucht wurde die Düngewirkung von organischen Nebenprodukten aus der Insektenzucht mit unterschiedlichen Eigenschaften zu Staudenbasilikum. Eine hoher Frischmasseertrag wurde nach Düngung von Insektenfraß aufgrund eines günstigen Verhältnis von N-P-K im Düngemittel festgestellt.

One of the key ways to improve the sustainability of agricultural systems is through diversification, taking advantage of synergies between farm enterprises. Among diversified systems, multispecies livestock farms with at least two animal enterprises have rarely been studied. We explored 95 organic farms from six countries, accounting for the proportion of animal enterprises, sales management, workforce size, and work organization. The study reveals various types of interactions between animal enterprises. Complementarities were observed between ruminant and monogastric enterprises, particularly fertilizer transfer from monogastric manure to grasslands. Milk production was often associated with on-farm processing and short distribution channels, which enhanced farm viability and reduced its dependency on herd productivity. Eleven out of the 95 farms combined above-average production efficiency, on-farm processing, and the majority of sales in short distribution channels. Their labor productivity converged toward 22 livestock units per annual work unit, regardless of the number of workers. Combining farm structure; livestock production efficiency; social elements, such as the workforce; and sales management led us to distinguish four types of farms: (i) small and very autonomous grassland farms with on-farm processing and short distribution channels; (ii) dairy farms associated with a high-density pig or poultry enterprise, whose feed purchase contributes to high rates of cattle feeding self-sufficiency and stocking rate; (iii) large farms with an extensive, grassland beef enterprise associated with either sheep or monogastrics; and (iv) dairy sheep associated with goat or beef cattle on rangelands, with high added-value products enhancing salaries. This study highlights for the first time the diversity of organic multispecies livestock farms and how consistent patterns of interactions among farm structure, livestock management, sales management, and workforce manage

Untersucht wurde die Düngewirkung von organischen Nebenprodukten aus der Insektenzucht mit unterschiedlichen Eigenschaften zu Staudenbasilikum. Eine hoher Frischmasseertrag wurde nach Düngung von Insektenfraß aufgrund eines günstigen Verhältnis von N-P-K im Düngemittel festgestellt.

One of the key ways to improve the sustainability of agricultural systems is through diversification, taking advantage of synergies between farm enterprises. Among diversified systems, multispecies livestock farms with at least two animal enterprises have rarely been studied. We explored 95 organic farms from six countries, accounting for the proportion of animal enterprises, sales management, workforce size, and work organization. The study reveals various types of interactions between animal enterprises. Complementarities were observed between ruminant and monogastric enterprises, particularly fertilizer transfer from monogastric manure to grasslands. Milk production was often associated with on-farm processing and short distribution channels, which enhanced farm viability and reduced its dependency on herd productivity. Eleven out of the 95 farms combined above-average production efficiency, on-farm processing, and the majority of sales in short distribution channels. Their labor productivity converged toward 22 livestock units per annual work unit, regardless of the number of workers. Combining farm structure; livestock production efficiency; social elements, such as the workforce; and sales management led us to distinguish four types of farms: (i) small and very autonomous grassland farms with on-farm processing and short distribution channels; (ii) dairy farms associated with a high-density pig or poultry enterprise, whose feed purchase contributes to high rates of cattle feeding self-sufficiency and stocking rate; (iii) large farms with an extensive, grassland beef enterprise associated with either sheep or monogastrics; and (iv) dairy sheep associated with goat or beef cattle on rangelands, with high added-value products enhancing salaries. This study highlights for the first time the diversity of organic multispecies livestock farms and how consistent patterns of interactions among farm structure, livestock management, sales management, and workforce manage

Die Integration von Spitzwegerich in Feldfuttergemenge führt durch seine tief reichenden Wurzeln im Vergleich zu Gemengen mit Gräsern zu höheren Schnittguterträgen in Trockenperioden. Des Weiteren senkt Spitzwegerich durch seine nitrifikationshemmende Wirkung die Auswaschung von Nitratstickstoff.

Die Steigerung der Produktivität und die Erhaltung der Böden sind die größten Herausforderungen, denen sich der ökologische Landbau in Zukunft stellen muss. In diesem Workshop werden die Möglichkeiten des Leguminosenanbaus in Fruchtfolgen und die damit verbundenen Risiken und Chancen diskutiert.

In a two-year model crop rotation consisting of overwintering legumes as cover crops followed by maize in the first year and grain peas in the second year, the phytopathological risks and the potential of expanding the cultivation of legume cover crops in minimum tillage systems were examined.

In a two-year model crop rotation consisting of overwintering legumes as cover crops followed by maize in the first year and grain peas in the second year, the phytopathological risks and the potential of expanding the cultivation of legume cover crops in minimum tillage systems were examined.

In Feldversuchen mit Zwischenfrüchten wurden über Winter hohe Stickstoffverluste aus der Sprossmasse festgestellt. Zusammen mit einem weiten C/N-Verhältnis im Stängel, könnte dies erklären, warum eine zusätzliche Mineralisierung im Frühjahr im Vergleich zur unbehandelten Kontrolle relativ gering ausfiel.

Stickstoffsaldo gehört zu den wichtigstene Agrarumweltindikatoren. Durch eine systematische Literatursuche zur Stickstoffeffizienz wurden 3107 Studien identifiziert. Nach Sichtung wurden 31 Studien ausgewertet. N-Input, Rotationsdauer und N-Output wurden als die wichtigsten Einflüsse bestimmt.

Unsere Ergebnisse deuten darauf hin, dass das Mulchen für den Gemüseanbau von Vorteil ist, da viele Bodenparameter für die Anpassung an den Klimawandel von Vorteil sind und gleichzeitig die N2O-Emissinen nicht erhöhen.

Die Integration von Spitzwegerich in Feldfuttergemenge führt durch seine tief reichenden Wurzeln im Vergleich zu Gemengen mit Gräsern zu höheren Schnittguterträgen in Trockenperioden. Des Weiteren senkt Spitzwegerich durch seine nitrifikationshemmende Wirkung die Auswaschung von Nitratstickstoff.

In ökologischen Kartoffeln wurde die Düngung mit Haarmehlpellets (HMP) und organischem Mulch verglichen. In der Dürre 2020 wurde weniger N in den Mulchvarianten mineralisiert, was zu einem erhöhten N-Auswaschungsrisiko vor Winter, aber keinen sign. Ertragsunterschieden führte.

Mithilfe drohnebasierter multispektraler Aufnahmen wurde die räumliche Variabilität des Luzerneanteils in Luzerne-Gras-Gemenge auf zwei Schlägen in Hessen, Deutschland, mit hoher Genauigkeit geschätzt. Daraus erstellte Karten ermöglichen die räumliche Analyse der Bestände hinsichtlich N-Fixierungpotenzial.

Mulch aus Gründüngungen wird zur Klimawandelanpassung, Nährstoffversorgung, zum Pflanzenschutz und Bodenfruchtbarkeitsmanagement eingesetzt. Der Workshop stellt den aktuellen Stand des Wissens und der Praxis vor. Er zielt darauf ab, Forschung, Beratung und Landwirte enger miteinander zu verbinden.

One of the key ways to improve the sustainability of agricultural systems is through diversification, taking advantage of synergies between farm enterprises. Among diversified systems, multispecies livestock farms with at least two animal enterprises have rarely been studied. We explored 95 organic farms from six countries, accounting for the proportion of animal enterprises, sales management, workforce size, and work organization. The study reveals various types of interactions between animal enterprises. Complementarities were observed between ruminant and monogastric enterprises, particularly fertilizer transfer from monogastric manure to grasslands. Milk production was often associated with on-farm processing and short distribution channels, which enhanced farm viability and reduced its dependency on herd productivity. Eleven out of the 95 farms combined above-average production efficiency, on-farm processing, and the majority of sales in short distribution channels. Their labor productivity converged toward 22 livestock units per annual work unit, regardless of the number of workers. Combining farm structure; livestock production efficiency; social elements, such as the workforce; and sales management led us to distinguish four types of farms: (i) small and very autonomous grassland farms with on-farm processing and short distribution channels; (ii) dairy farms associated with a high-density pig or poultry enterprise, whose feed purchase contributes to high rates of cattle feeding self-sufficiency and stocking rate; (iii) large farms with an extensive, grassland beef enterprise associated with either sheep or monogastrics; and (iv) dairy sheep associated with goat or beef cattle on rangelands, with high added-value products enhancing salaries. This study highlights for the first time the diversity of organic multispecies livestock farms and how consistent patterns of interactions among farm structure, livestock management, sales management, and workforce manage

Die Heterogenität von Ökobetrieben erschwert die Identifikation von Faktoren für ein optimiertes Nährstoffmanagement. Mittels Clusteranalyse werden in diesem Beitrag ausgewählte Ökobetriebe segmentiert und damit die Grundlage für eine verbesserte Analyse der ökonomischen N-Effizienz geschaffen.

Die Bruttoerträge, unter Einbezug unbepflanzter Fahrgassen für die Mulchausbringung, wirken sich entscheidend auf die Wirtschaftlichkeit einer regenerativen Kartoffelanbau-Methode unter Transfermulch aus. Außerdem relevant sind die Gestaltung der Mulchprozesskette sowie die Mulcherträge und -kosten.

Der Rückgang der Futternutzung von Kleegras im Ökologischen Landbau erfordert nährstoff-/kosteneffiziente Nutzungsalternativen. Der Beitrag ermittelt in einer ökonomischen und Stoffstrom-Analyse Verfahrenskosten/Stickstoff-Bereitstellung (N-Bereitstellungskosten) verschiedener KG-Nutzungsverfahren.

Mithilfe drohnebasierter multispektraler Aufnahmen wurde die räumliche Variabilität des Luzerneanteils in Luzerne-Gras-Gemenge auf zwei Schlägen in Hessen, Deutschland, mit hoher Genauigkeit geschätzt. Daraus erstellte Karten ermöglichen die räumliche Analyse der Bestände hinsichtlich N-Fixierungpotenzial.

This report presents the methods and results from preliminary trials with composting marine residual raw materials under the auspices of MARIGREEN, a project funded by the ERA-NET BlueBio cofund program. The main goal of MARIGREEN is to upgrade poorly utilized residual raw materials from blue value chains (fish, shells, algae) for use as fertilizer and biostimulants in organic farming. The project is led by UPB (Romania) and is in collaboration with USAMV (Romania), AUTh (Greece), DTU (Denmark), UCPH (Denmark), NORCE (Norway), and the industrial partners Alumichem AS (Denmark), Norgeskjell AS (Norway), Sigurd Folland AS (Norway), Fjordlaks AS (Norway), and Algea AS (Norway). The compost experiments were carried out at three different levels: small-scale (2 litres) in so-called Dewar flasks; medium-scale (140 liters) with a Jordakompost® insulated compost drum; and large-scale (approx. 7 m3) with windrow composting. The first experiments in the Dewar flasks were based on known raw materials such as horse dung, sawdust, and straw and were intended to familiarize ourselves with the equipment and the method, which is called a self-heating test. This test is usually used to estimate the maturity and stability of finished compost, but here we wanted to look at heat development in fresh material. The trials with the familiar raw materials were followed by trials with the marine residual raw materials, tangle kelp, two types of algae fiber from processing rockweed (brown seaweed), ground fish bones from hydrolyzed cod heads, and dried fish meal from fish in the cod family. These materials have, to our knowledge, not yet been tested in Dewar flasks. As an alternative bulking material in the Dewar bottles and in the compost drum, we experimented with expanded clay aggregates (Leca®). The experiment with horse dung confirmed that the Dewar flasks can be used to estimate the potential for heat generation in fresh material. The marine residual raw materials also developed heat

This final report from the project “Residual materials from marine industries as fertilisers in organic agriculture” is an example of blue-green collaboration. Such collaboration has been a strategic goal for many Norwegian research and innovation activities since the terms bioeconomy and circular economy came high on the agenda. Significant amounts of residual raw materials from marine industry are still poorly utilized. Traditionally, seaweeds and residues of fish and other sea animals were applied as feed and fertilisers along the coast of Norway, as elsewhere in coastal regions. These valuable materials should still be applied in agriculture, but the application needs to be adapted to a more professional and large-scale production. Organic agriculture aims at being selfsufficient in nutrients and other inputs for the production. A further aim is to recycle nutrients and organic matter not only inside the farm by feeding manure-producing animals, but by recycling nutrients lost from the farm by sales of products, and by runoff and emissions. The RESTOR project (2018-2022) has provided resources for establishing a significant research and developmental work on marine-derived fertilisers at the Norwegian Centre for Organic Agriculture (NORSØK). Marine derived fertilisers, especially from sustainable collection or capture of natural renewable resources, may fit well to the aims of organic agriculture. The project has tested residual materials rich in bones from industry processing white fish species (cod, saithe, longfish etc.), and residual material from chemical extraction of rockweed. The materials have been tested as fertilisers and soil amendments, with controlled trials indoor and in the field. A general result is a very rapid growth effect of fishbones in the year of application, with a residual effect in subsequent years resembling that of dried poultry manure. The algae fiber has no immediate fertiliser effect but has a significant residual growth effect. D

The compost tea production process involves the use of a bioextractor (containing water), that is a tank equipped with an aeration device (pump). The on-farm compost is placed in a filter bag (hemp or nylon) and soaked in the water. Oxygenation is obtained by activating the recirculation of the aqueous medium of extraction via a pump. The extraction is carried out with a ratio of 1:5 v/v (20%). In order to ensure proper oxygenation, the timer should be set to a value of 15 minutes (on) every 3 hours (off). A further dilution can be necessary, after measuring the electrical conductivity, up to a ratio of 1:15 v/v, before using compost tea in soil (and on crop leaves). In sweet cherry orchards and in vineyards compost tea must be provided about three times during each season.

Background: Fertilization with organic waste compost can close the nutrient cycles between urban and rural environments. However, its effect on yield and soil fertility must be investigated. Aim: This study investigated the long-term effect of compost on soil nutrient and potentially toxic elements (PTEs) concentration, nutrient budgets, and nitrogen (N) mineralization and efficiency. Methods: After 21 years of annual compost application (100/400 kg N ha–1 year–1 [100BC/400BC]) alone and combined with mineral fertilization, soil was analyzed for pH, organic carbon (SOC), nutrient (total N and P, Nmin, extractable CAL-P, CAL-K, and Mg), and PTE (Cu, Ni, Zn) concentrations. Yields were recorded and nutrient/PTE budgets and apparent netmineralization (ANM, only 2019) were calculated. Results:Nefficiency was the highest in maize and formineral fertilization. Compost application led to lower N efficiencies, but increased ANM, SOC, pH, and soil N, and surpluses of N, P, and all PTEs. Higher PTE concentrations were only found in 400BC for Cu. Nutrient budgets correlatedwith soil nutrient concentration. A surplus of 16.1 kg P ha–1 year–1 and 19.5 kgKha–1 year–1 resulted in 1mg kg–1 increase in CAL-P and CAL-K over 21 years. Conclusion: Compost application supplies nutrients to crops with a minor risk of soilaccumulation of PTEs. However, the nutrient stoichiometry provided by compost does not match crop offtakes causing imbalances. Synchronization of compost N mineralization and plant N demand does not match and limits the yield effect. In winter wheat only 65–70% of Nmineralization occurred during the growth period.

Ved et relativt lavt input på 85 kg total-N i afgasset gylle kan en høj andel af vellykkede efterafgrøder (+75%) og salgsafgrøder hvert år øge udbytterne i forhold til et system med helårsgrøngødning.

This final report from the project “Residual materials from marine industries as fertilisers in organic agriculture” is an example of blue-green collaboration. Such collaboration has been a strategic goal for many Norwegian research and innovation activities since the terms bioeconomy and circular economy came high on the agenda. Significant amounts of residual raw materials from marine industry are still poorly utilized. Traditionally, seaweeds and residues of fish and other sea animals were applied as feed and fertilisers along the coast of Norway, as elsewhere in coastal regions. These valuable materials should still be applied in agriculture, but the application needs to be adapted to a more professional and large-scale production. Organic agriculture aims at being selfsufficient in nutrients and other inputs for the production. A further aim is to recycle nutrients and organic matter not only inside the farm by feeding manure-producing animals, but by recycling nutrients lost from the farm by sales of products, and by runoff and emissions. The RESTOR project (2018-2022) has provided resources for establishing a significant research and developmental work on marine-derived fertilisers at the Norwegian Centre for Organic Agriculture (NORSØK). Marine derived fertilisers, especially from sustainable collection or capture of natural renewable resources, may fit well to the aims of organic agriculture. The project has tested residual materials rich in bones from industry processing white fish species (cod, saithe, longfish etc.), and residual material from chemical extraction of rockweed. The materials have been tested as fertilisers and soil amendments, with controlled trials indoor and in the field. A general result is a very rapid growth effect of fishbones in the year of application, with a residual effect in subsequent years resembling that of dried poultry manure. The algae fiber has no immediate fertiliser effect but has a significant residual growth effect. D

Cover crops are cultivated during unproductive periods to provide ecosystem services, such as preventing nitrogen (N) leaching, and have the potential to increase soil organic carbon (C), thus contributing to climate change mitigation. Their effect on soil C storage depends on C input, which is challenging to quantify due to belowground sampling (roots and C deposited in the soil). Leguminous cover crops (in pure stands or in mixtures) increase the productivity of following main crops due to high N input, but also the risk of N losses, compromising the mitigation effect. As C and N services vary with cover crop type, tradeoffs could be minimized by species selection. The aim of this study was to assess C input from different cover crop species and mixtures, as well as N uptake in their biomass, and their effect on soil mineral N (SMN) and yield of the following crop. We conducted a field experiment in 2020-2021 at Foulum, Denmark (temperate oceanic climate, sandy loam soil), with seven treatments (five cover crops, control with volunteers, and bare soil) replicated four times. Cover crops undersown in spring barley (Hordeum vulgare L.) in May 2020 were: Lolium perenne L. (ryegrass, RG), Trifolium pratense L. (red clover, RC), Plantago lanceolata L. (plantain, PL) and the mixtures RG-PL and RG-PL-RC. On August 24, 2020, after barley harvest, PVC cylinders (diameter: 29.5 cm, height: 30 cm) were inserted in each plot (25 cm depth) and used for 13C-CO2 multiple-pulse isotopic labeling. Two sessions per week were conducted until cover crop sampling in November 2020, when C and N in above- and belowground biomass, as well C deposited in the soil were determined. Monthly soil sampling (20 cm depth) was performed from August 2020 until April 2021 to assess SMN. Then barley was sown to evaluate cover crops residual effect. Aboveground biomass was lowest in RG (1.5 Mg ha-1), and highest in RG-PL-RC (5.4 Mg ha-1). Total C input (above- and belowground) ranged from 1.6 to 4.3

Background: Fertilization with organic waste compost can close the nutrient cycles between urban and rural environments. However, its effect on yield and soil fertility must be investigated. Aim: This study investigated the long-term effect of compost on soil nutrient and potentially toxic elements (PTEs) concentration, nutrient budgets, and nitrogen (N) mineralization and efficiency. Methods: After 21 years of annual compost application (100/400 kg N ha–1 year–1 [100BC/400BC]) alone and combined with mineral fertilization, soil was analyzed for pH, organic carbon (SOC), nutrient (total N and P, Nmin, extractable CAL-P, CAL-K, and Mg), and PTE (Cu, Ni, Zn) concentrations. Yields were recorded and nutrient/PTE budgets and apparent netmineralization (ANM, only 2019) were calculated. Results:Nefficiency was the highest in maize and formineral fertilization. Compost application led to lower N efficiencies, but increased ANM, SOC, pH, and soil N, and surpluses of N, P, and all PTEs. Higher PTE concentrations were only found in 400BC for Cu. Nutrient budgets correlatedwith soil nutrient concentration. A surplus of 16.1 kg P ha–1 year–1 and 19.5 kgKha–1 year–1 resulted in 1mg kg–1 increase in CAL-P and CAL-K over 21 years. Conclusion: Compost application supplies nutrients to crops with a minor risk of soilaccumulation of PTEs. However, the nutrient stoichiometry provided by compost does not match crop offtakes causing imbalances. Synchronization of compost N mineralization and plant N demand does not match and limits the yield effect. In winter wheat only 65–70% of Nmineralization occurred during the growth period.

Data from a long-term field experiment in Norway, comparing digested and undigested slurry from organically managed dairy cows since 2011. The dataset includes chemical analyses of digested and non-digested slurry, soil characteristics at plot level of pH, extractable nutrients, loss on ignition; crop yields and botanical composition. These data supplement the findings presented and discussed in the research article Anaerobic digestion of animal manure – long-term effects on crop yields and soil characteristics.

Krarup Landbrug I/S er med til at demonstrere en ny vinterfodringsstrategi i forskningsprojektet WI-FI baseret på resultater fra Aarhus Universitet. Resultaterne viste, at drægtige søer tildelt foder med lavt protein-niveau i den efterfølgende laktation præsterede både en højere kuldtilvækst pr. dag og en højere fravænningsvægt end søer fodret efter de gældende protein-normer. Virker foderstrategien i praksis, vil det gavne både økonomi, klima og miljø. Se med her hvor økologisk soholder Niels Thing fortæller om sine erfaringer på bedriften i Krarup

• Clover grass as a co-substrate in biogas production is an important source of biogenic nitrogen contributing to carbon sequestration and biodiversity • Anaerobic digestion has a high potential for reduction of GHG emissions • High nitrogen efficiency of ammonia-rich fractions • Dried fiber fraction immobilizes nitrogen but is usable as phosphorus source for legume crops

EFTERAFGRØDER INDGÅR OFTE i sædskifter for at samle kvælstof op, som frigives, når planterester fra hovedafgrøden nedbrydes. Der er positive sideeffekter for klimaet i form af kulstofbinding og opsamling af kvælstof, som ellers efter udvaskning er en indirekte kilde til drivhusgassen lattergas. Men efterafgrøder bliver også selv til planterester - enten på grund af frost, eller når de om foråret afsluttes gennem jordbearbejdning. Under den nedbrydning, som følger, frigives den kvælstof, som er samlet op om efteråret. Nedbrydning kan danne lattergas, idet jordens mikroorganismer er aktive længe før en ny afgrøde er klar til at optage kvælstof fra efterafgrøden, er . De står for processer som nitrifikation og denitrifikation, som begge kan føre til udledning af lattergas. Hvis lattergas udledes fra efterafgrøders planterester om foråret, er det dårligt for det samlede klimaaftryk. Kriterier, når du skal vælge efterafgrøde, er: • effektiv opsamling af kvælstof om efteråret • at kvælstoffet kan udnyttes af næste hovedafgrøde • at kvælstof frigives i et tempo, hvor en ny afgrøde kan udnytte denne eftervirkning.

There is a need to take care of the nutrients in the system. Anaerobic digestion is a valuable way to convert the nutrients and produce renewable energy. A model is presented that use grass-clover as feedstock for anaerobic digestion and separate the digestate in 3 fractions. Anaerobic digestion and separation have positive effect on N2O-emissions. But a very dilute solution of ammonia and sulfur generated high emissions when applied to the soil with 100 kg N per hectare.

Ved et relativt lavt input på 85 kg total-N i afgasset gylle kan en høj andel af vellykkede efterafgrøder (+75%) og salgsafgrøder hvert år øge udbytterne i forhold til et system med helårsgrøngødning.

Agroecology can be defined as an integrated approach to agriculture and food systems, combining ecological and social principles to agricultural management and food systems design. Thanks to its holistic approach towards sustainability, agroecology can help tackle climate change challenges, from both mitigation and adaptation perspectives. Agroecological practices such as the use of cover crops and green manures have the potential to increase carbon stored in the soil, as well as soil fertility, mitigating climate change and at the same time improving crop productivity. Nonetheless, it has been shown that practices that can have a positive effect on carbon sequestration might increase emissions of other greenhouse gasses, such as nitrous oxide. This webinar will provide an overview on agroecological practices and climate change, and present results from field experiments on the effect of cover crops on carbon and nitrogen in the soil, with related implications for climate change mitigation.

EFTERAFGRØDER INDGÅR OFTE i sædskifter for at samle kvælstof op, som frigives, når planterester fra hovedafgrøden nedbrydes. Der er positive sideeffekter for klimaet i form af kulstofbinding og opsamling af kvælstof, som ellers efter udvaskning er en indirekte kilde til drivhusgassen lattergas. Men efterafgrøder bliver også selv til planterester - enten på grund af frost, eller når de om foråret afsluttes gennem jordbearbejdning. Under den nedbrydning, som følger, frigives den kvælstof, som er samlet op om efteråret. Nedbrydning kan danne lattergas, idet jordens mikroorganismer er aktive længe før en ny afgrøde er klar til at optage kvælstof fra efterafgrøden, er . De står for processer som nitrifikation og denitrifikation, som begge kan føre til udledning af lattergas. Hvis lattergas udledes fra efterafgrøders planterester om foråret, er det dårligt for det samlede klimaaftryk. Kriterier, når du skal vælge efterafgrøde, er: • effektiv opsamling af kvælstof om efteråret • at kvælstoffet kan udnyttes af næste hovedafgrøde • at kvælstof frigives i et tempo, hvor en ny afgrøde kan udnytte denne eftervirkning.

Cover crops are cultivated during unproductive periods to provide ecosystem services, such as preventing nitrogen (N) leaching, and have the potential to increase soil organic carbon (C), thus contributing to climate change mitigation. Their effect on soil C storage depends on C input, which is challenging to quantify due to belowground sampling (roots and C deposited in the soil). Leguminous cover crops (in pure stands or in mixtures) increase the productivity of following main crops due to high N input, but also the risk of N losses, compromising the mitigation effect. As C and N services vary with cover crop type, tradeoffs could be minimized by species selection. The aim of this study was to assess C input from different cover crop species and mixtures, as well as N uptake in their biomass, and their effect on soil mineral N (SMN) and yield of the following crop. We conducted a field experiment in 2020-2021 at Foulum, Denmark (temperate oceanic climate, sandy loam soil), with seven treatments (five cover crops, control with volunteers, and bare soil) replicated four times. Cover crops undersown in spring barley (Hordeum vulgare L.) in May 2020 were: Lolium perenne L. (ryegrass, RG), Trifolium pratense L. (red clover, RC), Plantago lanceolata L. (plantain, PL) and the mixtures RG-PL and RG-PL-RC. On August 24, 2020, after barley harvest, PVC cylinders (diameter: 29.5 cm, height: 30 cm) were inserted in each plot (25 cm depth) and used for 13C-CO2 multiple-pulse isotopic labeling. Two sessions per week were conducted until cover crop sampling in November 2020, when C and N in above- and belowground biomass, as well C deposited in the soil were determined. Monthly soil sampling (20 cm depth) was performed from August 2020 until April 2021 to assess SMN. Then barley was sown to evaluate cover crops residual effect. Aboveground biomass was lowest in RG (1.5 Mg ha-1), and highest in RG-PL-RC (5.4 Mg ha-1). Total C input (above- and belowground) ranged from 1.6 to 4.3

There is a need to take care of the nutrients in the system. Anaerobic digestion is a valuable way to convert the nutrients and produce renewable energy. A model is presented that use grass-clover as feedstock for anaerobic digestion and separate the digestate in 3 fractions. Anaerobic digestion and separation have positive effect on N2O-emissions. But a very dilute solution of ammonia and sulfur generated high emissions when applied to the soil with 100 kg N per hectare.

• Clover grass as a co-substrate in biogas production is an important source of biogenic nitrogen contributing to carbon sequestration and biodiversity • Anaerobic digestion has a high potential for reduction of GHG emissions • High nitrogen efficiency of ammonia-rich fractions • Dried fiber fraction immobilizes nitrogen but is usable as phosphorus source for legume crops

This report presents the methods and results from preliminary trials with composting marine residual raw materials under the auspices of MARIGREEN, a project funded by the ERA-NET BlueBio cofund program. The main goal of MARIGREEN is to upgrade poorly utilized residual raw materials from blue value chains (fish, shells, algae) for use as fertilizer and biostimulants in organic farming. The project is led by UPB (Romania) and is in collaboration with USAMV (Romania), AUTh (Greece), DTU (Denmark), UCPH (Denmark), NORCE (Norway), and the industrial partners Alumichem AS (Denmark), Norgeskjell AS (Norway), Sigurd Folland AS (Norway), Fjordlaks AS (Norway), and Algea AS (Norway). The compost experiments were carried out at three different levels: small-scale (2 litres) in so-called Dewar flasks; medium-scale (140 liters) with a Jordakompost® insulated compost drum; and large-scale (approx. 7 m3) with windrow composting. The first experiments in the Dewar flasks were based on known raw materials such as horse dung, sawdust, and straw and were intended to familiarize ourselves with the equipment and the method, which is called a self-heating test. This test is usually used to estimate the maturity and stability of finished compost, but here we wanted to look at heat development in fresh material. The trials with the familiar raw materials were followed by trials with the marine residual raw materials, tangle kelp, two types of algae fiber from processing rockweed (brown seaweed), ground fish bones from hydrolyzed cod heads, and dried fish meal from fish in the cod family. These materials have, to our knowledge, not yet been tested in Dewar flasks. As an alternative bulking material in the Dewar bottles and in the compost drum, we experimented with expanded clay aggregates (Leca®). The experiment with horse dung confirmed that the Dewar flasks can be used to estimate the potential for heat generation in fresh material. The marine residual raw materials also developed heat

The compost tea production process involves the use of a bioextractor (containing water), that is a tank equipped with an aeration device (pump). The on-farm compost is placed in a filter bag (hemp or nylon) and soaked in the water. Oxygenation is obtained by activating the recirculation of the aqueous medium of extraction via a pump. The extraction is carried out with a ratio of 1:5 v/v (20%). In order to ensure proper oxygenation, the timer should be set to a value of 15 minutes (on) every 3 hours (off). A further dilution can be necessary, after measuring the electrical conductivity, up to a ratio of 1:15 v/v, before using compost tea in soil (and on crop leaves). In sweet cherry orchards and in vineyards compost tea must be provided about three times during each season.

Krarup Landbrug I/S ved Varde har i vinteren 2022-2023 været med til at demonstrere en ny vinterfodringsstrategi til drægtige søer i forskningsprojektet WI-FI. Demonstrationen er baseret på resultater fra Aarhus Universitet. Hos Krarup Landbrug er de gået skridtet videre og har lagt en individuel foderstrategi for de lakterende søer. Se med i videoen hvor økologisk soholder Niels Thing fortæller om den trekomponent fodervogn, der i samspil med en doserings app sørger for, at hver enkelt so får dækket sit behov i forhold til; huld, cyklusdag, kuldstørrelse, temperatur og græsdækket. Udstyr og optimeringskurver er udviklet af Niels selv.

Bertel Hestbjerg, der er manden bag den økologiske ’Poppelgris’ medvirker i forskningsprojektet WI-FI, der udvikler nye vinterfodringsstrategier til økologiske søer. Fodringen optimeres ved at nedjustere 'protein-normen' samtidig med et restprodukt udnyttes som grovfoder. Med den helt rette balance imellem grov- og kraftfoder kan overforsyning af søerne undgås - til gavn for både økonomi, klima og miljø.

Krarup Landbrug I/S er med til at demonstrere en ny vinterfodringsstrategi i forskningsprojektet WI-FI baseret på resultater fra Aarhus Universitet. Resultaterne viste, at drægtige søer tildelt foder med lavt protein-niveau i den efterfølgende laktation præsterede både en højere kuldtilvækst pr. dag og en højere fravænningsvægt end søer fodret efter de gældende protein-normer. Virker foderstrategien i praksis, vil det gavne både økonomi, klima og miljø. Se med her hvor økologisk soholder Niels Thing fortæller om sine erfaringer på bedriften i Krarup

Background: Fertilization with organic waste compost can close the nutrient cycles between urban and rural environments. However, its effect on yield and soil fertility must be investigated. Aim: This study investigated the long-term effect of compost on soil nutrient and potentially toxic elements (PTEs) concentration, nutrient budgets, and nitrogen (N) mineralization and efficiency. Methods: After 21 years of annual compost application (100/400 kg N ha–1 year–1 [100BC/400BC]) alone and combined with mineral fertilization, soil was analyzed for pH, organic carbon (SOC), nutrient (total N and P, Nmin, extractable CAL-P, CAL-K, and Mg), and PTE (Cu, Ni, Zn) concentrations. Yields were recorded and nutrient/PTE budgets and apparent netmineralization (ANM, only 2019) were calculated. Results:Nefficiency was the highest in maize and formineral fertilization. Compost application led to lower N efficiencies, but increased ANM, SOC, pH, and soil N, and surpluses of N, P, and all PTEs. Higher PTE concentrations were only found in 400BC for Cu. Nutrient budgets correlatedwith soil nutrient concentration. A surplus of 16.1 kg P ha–1 year–1 and 19.5 kgKha–1 year–1 resulted in 1mg kg–1 increase in CAL-P and CAL-K over 21 years. Conclusion: Compost application supplies nutrients to crops with a minor risk of soilaccumulation of PTEs. However, the nutrient stoichiometry provided by compost does not match crop offtakes causing imbalances. Synchronization of compost N mineralization and plant N demand does not match and limits the yield effect. In winter wheat only 65–70% of Nmineralization occurred during the growth period.

Data from a long-term field experiment in Norway, comparing digested and undigested slurry from organically managed dairy cows since 2011. The dataset includes chemical analyses of digested and non-digested slurry, soil characteristics at plot level of pH, extractable nutrients, loss on ignition; crop yields and botanical composition. These data supplement the findings presented and discussed in the research article Anaerobic digestion of animal manure – long-term effects on crop yields and soil characteristics.

Der er positiv klimaeffekt af at dyrke kløvergræs, høste græsset til biogasproduktion og efterfølgende gøde med effektiv gødning fra biogasanlægget. Men økonomisk er det endnu ikke attraktivt for landmændene, der ofte kan få billig husdyrgødning fra konventionelle landmænd.

EFTERAFGRØDER INDGÅR OFTE i sædskifter for at samle kvælstof op, som frigives, når planterester fra hovedafgrøden nedbrydes. Der er positive sideeffekter for klimaet i form af kulstofbinding og opsamling af kvælstof, som ellers efter udvaskning er en indirekte kilde til drivhusgassen lattergas. Men efterafgrøder bliver også selv til planterester - enten på grund af frost, eller når de om foråret afsluttes gennem jordbearbejdning. Under den nedbrydning, som følger, frigives den kvælstof, som er samlet op om efteråret. Nedbrydning kan danne lattergas, idet jordens mikroorganismer er aktive længe før en ny afgrøde er klar til at optage kvælstof fra efterafgrøden, er . De står for processer som nitrifikation og denitrifikation, som begge kan føre til udledning af lattergas. Hvis lattergas udledes fra efterafgrøders planterester om foråret, er det dårligt for det samlede klimaaftryk. Kriterier, når du skal vælge efterafgrøde, er: • effektiv opsamling af kvælstof om efteråret • at kvælstoffet kan udnyttes af næste hovedafgrøde • at kvælstof frigives i et tempo, hvor en ny afgrøde kan udnytte denne eftervirkning.

Bertel Hestbjerg, der er manden bag den økologiske ’Poppelgris’ medvirker i forskningsprojektet WI-FI, der udvikler nye vinterfodringsstrategier til økologiske søer. Fodringen optimeres ved at nedjustere 'protein-normen' samtidig med et restprodukt udnyttes som grovfoder. Med den helt rette balance imellem grov- og kraftfoder kan overforsyning af søerne undgås - til gavn for både økonomi, klima og miljø.