Measurements of nitrous oxide (N2O) emissions from agriculture are essential for understanding the complex soil\uffe2\uff80\uff93crop\uffe2\uff80\uff93climate processes, but there are practical and economic limits to the spatial and temporal extent over which measurements can be made. Therefore, N2O models have an important role to play. As models are comparatively cheap to run, they can be used to extrapolate field measurements to regional or national scales, to simulate emissions over long time periods, or to run scenarios to compare mitigation practices. Process\uffe2\uff80\uff90based models can also be used as an aid to understanding the underlying processes, as they can simulate feedbacks and interactions that can be difficult to distinguish in the field. However, when applying models, it is important to understand the conceptual process differences in models, how conceptual understanding changed over time in various models, and the model requirements and limitations to ensure that the model is well suited to the purpose of the investigation and the type of system being simulated. The aim of this paper is to give the reader a high\uffe2\uff80\uff90level overview of some of the important issues that should be considered when modeling. This includes conceptual understanding of widely used models, common modeling techniques such as calibration and validation, assessing model fit, sensitivity analysis, and uncertainty assessment. We also review examples of N2O modeling for different purposes and describe three commonly used process\uffe2\uff80\uff90based N2O models (APSIM, DayCent, and DNDC).10% of people on Earth) will experience severe food deficiencies by 2050. Increased production is urgently needed, but high costs and volatile prices are driving farmers into debt. Zero budget natural farming (ZBNF) is a grassroots movement that aims to improve farm viability by reducing costs. In Andhra Pradesh alone, 523,000 farmers have converted 13% of productive agricultural area to ZBNF. However, sustainability of ZBNF is questioned because external nutrient inputs are limited, which could cause a crash in food production. Here, we show that ZBNF is likely to reduce soil degradation and could provide yield benefits for low-input farmers. Nitrogen fixation, either by free-living nitrogen fixers in soil or symbiotic nitrogen fixers in legumes, is likely to provide the major portion of nitrogen available to crops. However, even with maximum potential nitrogen fixation and release, only 52-80% of the national average nitrogen applied as fertilizer is expected to be supplied. Therefore, in higher-input systems, yield penalties are likely. Since biological fixation from the atmosphere is possible only with nitrogen, ZBNF could limit the supply of other nutrients. Further research is needed in higher-input systems to ensure that mass conversion to ZBNF does not limit India's capacity to feed itself.", "keywords": ["Monitoring", "IEAS/POO2501/1", "NE/S009019/1", "330", "Supplementary Data", "QH301 Biology", "NE/P004830/1", "WHEAT", "01 natural sciences", "630", "12. Responsible consumption", "QH301", "NE/M021327/1", "SOIL PHYSICAL-PROPERTIES", "SDG 7 - Affordable and Clean Energy", "FERTILIZER", "Renewable Energy", "Wellcome Trust", "SDG 2 - Zero Hunger", "Nature and Landscape Conservation", "0105 earth and related environmental sciences", "Planning and Development", "2. Zero hunger", "Global and Planetary Change", "Geography", "Policy and Law", "Ecology", "Sustainability and the Environment", "Natural Environment Research Council (NERC)", "Sustainable and Healthy Food Systems (SHEFS)", "NE/P019455/1", "1. No poverty", "04 agricultural and veterinary sciences", "15. Life on land", "6. Clean water", "Management", "NITROGEN", "Urban Studies", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "INDIA", "Economic and Social Research Council (ESRC)", "Food Science"]}, "links": [{"href": "https://www.nature.com/articles/s41893-019-0469-x.pdf"}, {"href": "https://doi.org/10.1038/s41893-019-0469-x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Nature%20Sustainability", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1038/s41893-019-0469-x", "name": "item", "description": "10.1038/s41893-019-0469-x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1038/s41893-019-0469-x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-01-20T00:00:00Z"}}, {"id": "10.1111/gcb.14878", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:19:22Z", "type": "Journal Article", "created": "2019-10-22", "title": "Which practices co\u2010deliver food security, climate change mitigation and adaptation, and combat land degradation and desertification?", "description": "Abstract
There is a clear need for transformative change in the land management and food production sectors to address the global land challenges of climate change mitigation, climate change adaptation, combatting land degradation and desertification, and delivering food security (referred to hereafter as \uffe2\uff80\uff9cland challenges\uffe2\uff80\uff9d). We assess the potential for 40 practices to address these land challenges and find that: Nine options deliver medium to large benefits for all four land challenges. A further two options have no global estimates for adaptation, but have medium to large benefits for all other land challenges. Five options have large mitigation potential (>3\uffc2\uffa0Gt CO2eq/year) without adverse impacts on the other land challenges. Five options have moderate mitigation potential, with no adverse impacts on the other land challenges. Sixteen practices have large adaptation potential (>25 million people benefit), without adverse side effects on other land challenges. Most practices can be applied without competing for available land. However, seven options could result in competition for land. A large number of practices do not require dedicated land, including several land management options, all value chain options, and all risk management options. Four options could greatly increase competition for land if applied at a large scale, though the impact is scale and context specific, highlighting the need for safeguards to ensure that expansion of land for mitigation does not impact natural systems and food security. A number of practices, such as increased food productivity, dietary change and reduced food loss and waste, can reduce demand for land conversion, thereby potentially freeing\uffe2\uff80\uff90up land and creating opportunities for enhanced implementation of other practices, making them important components of portfolios of practices to address the combined land challenges.There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international \uffe2\uff80\uff984p1000\uffe2\uff80\uff99 initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long\uffe2\uff80\uff90term experiments and space\uffe2\uff80\uff90for\uffe2\uff80\uff90time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.This study evaluates the dynamics of soil organic carbon (SOC) under perennial crops across the globe. It quantifies the effect of change from annual to perennial crops and the subsequent temporal changes in SOC stocks during the perennial crop cycle. It also presents an empirical model to estimate changes in the SOC content under crops as a function of time, land use, and site characteristics. We used a harmonized global dataset containing paired\uffe2\uff80\uff90comparison empirical values of SOC and different types of perennial crops (perennial grasses, palms, and woody plants) with different end uses: bioenergy, food, other bio\uffe2\uff80\uff90products, and short rotation coppice. Salient outcomes include: a 20\uffe2\uff80\uff90year period encompassing a change from annual to perennial crops led to an average 20% increase in SOC at 0\uffe2\uff80\uff9330\uffc2\uffa0cm (6.0\uffc2\uffa0\uffc2\uffb1\uffc2\uffa04.6\uffc2\uffa0Mg/ha gain) and a total 10% increase over the 0\uffe2\uff80\uff93100\uffc2\uffa0cm soil profile (5.7\uffc2\uffa0\uffc2\uffb1\uffc2\uffa010.9\uffc2\uffa0Mg/ha). A change from natural pasture to perennial crop decreased SOC stocks by 1% over 0\uffe2\uff80\uff9330\uffc2\uffa0cm (\uffe2\uff88\uff922.5\uffc2\uffa0\uffc2\uffb1\uffc2\uffa04.2\uffc2\uffa0Mg/ha) and 10% over 0\uffe2\uff80\uff93100\uffc2\uffa0cm (\uffe2\uff88\uff9213.6\uffc2\uffa0\uffc2\uffb1\uffc2\uffa08.9\uffc2\uffa0Mg/ha). The effect of a land use change from forest to perennial crops did not show significant impacts, probably due to the limited number of plots; but the data indicated that while a 2% increase in SOC was observed at 0\uffe2\uff80\uff9330\uffc2\uffa0cm (16.81\uffc2\uffa0\uffc2\uffb1\uffc2\uffa055.1\uffc2\uffa0Mg/ha), a decrease in 24% was observed at 30\uffe2\uff80\uff93100\uffc2\uffa0cm (\uffe2\uff88\uff9240.1\uffc2\uffa0\uffc2\uffb1\uffc2\uffa016.8\uffc2\uffa0Mg/ha). Perennial crops generally accumulate SOC through time, especially woody crops; and temperature was the main driver explaining differences in SOC dynamics, followed by crop age, soil bulk density, clay content, and depth. We present empirical evidence showing that the FAO perennialization strategy is reasonable, underscoring the role of perennial crops as a useful component of climate change mitigation strategies.Simulation models represent soil organic carbon (SOC) dynamics in global carbon (C) cycle scenarios to support climate\uffe2\uff80\uff90change studies. It is imperative to increase confidence in long\uffe2\uff80\uff90term predictions of SOC dynamics by reducing the uncertainty in model estimates. We evaluated SOC simulated from an ensemble of 26 process\uffe2\uff80\uff90based C models by comparing simulations to experimental data from seven long\uffe2\uff80\uff90term bare\uffe2\uff80\uff90fallow (vegetation\uffe2\uff80\uff90free) plots at six sites: Denmark (two sites), France, Russia, Sweden and the United Kingdom. The decay of SOC in these plots has been monitored for decades since the last inputs of plant material, providing the opportunity to test decomposition without the continuous input of new organic material. The models were run independently over multi\uffe2\uff80\uff90year simulation periods (from 28 to 80\uffc2\uffa0years) in a blind test with no calibration (Bln) and with the following three calibration scenarios, each providing different levels of information and/or allowing different levels of model fitting: (a) calibrating decomposition parameters separately at each experimental site (Spe); (b) using a generic, knowledge\uffe2\uff80\uff90based, parameterization applicable in the Central European region (Gen); and (c) using a combination of both (a) and (b) strategies (Mix). We addressed uncertainties from different modelling approaches with or without spin\uffe2\uff80\uff90up initialization of SOC. Changes in the multi\uffe2\uff80\uff90model median (MMM) of SOC were used as descriptors of the ensemble performance. On average across sites, Gen proved adequate in describing changes in SOC, with MMM equal to average SOC (and standard deviation) of 39.2 (\uffc2\uffb115.5)\uffc2\uffa0Mg\uffc2\uffa0C/ha compared to the observed mean of 36.0 (\uffc2\uffb119.7)\uffc2\uffa0Mg\uffc2\uffa0C/ha (last observed year), indicating sufficiently reliable SOC estimates. Moving to Mix (37.5\uffc2\uffa0\uffc2\uffb1\uffc2\uffa016.7\uffc2\uffa0Mg\uffc2\uffa0C/ha) and Spe (36.8\uffc2\uffa0\uffc2\uffb1\uffc2\uffa019.8\uffc2\uffa0Mg\uffc2\uffa0C/ha) provided only marginal gains in accuracy, but modellers would need to apply more knowledge and a greater calibration effort than in Gen, thereby limiting the wider applicability of models.
", "keywords": ["[SDE] Environmental Sciences", "330", "550", "Supplementary Data", "soil organic carbon dynamics", "QH301 Biology", "[SDE.MCG]Environmental Sciences/Global Changes", "Soil organic carbon dynamics", "bare\u2010fallow soils", "[SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study", "630", "protocol for model comparison", "Russia", "QH301", "Soil", "NE/M021327/1", "SDG 13 - Climate Action", "Environmental Chemistry", "774378", "process based models", "European Commission", "[SDV.SA.SDS] Life Sciences [q-bio]/Agricultural sciences/Soil study", "General Environmental Science", "Sweden", "Global and Planetary Change", "Ecology", "Natural Environment Research Council (NERC)", "NE/P019455/1", "bare-fallow soils", "Uncertainty", "Agriculture", "04 agricultural and veterinary sciences", "15. Life on land", "Carbon", "United Kingdom", "process-based models", "[SDE.MCG] Environmental Sciences/Global Changes", "13. Climate action", "[SDE]Environmental Sciences", "bare-fallow soils; model parametrization; process-based models; protocol for model comparison; soil organic carbon dynamics", "0401 agriculture", " forestry", " and fisheries", "774124", "France", "bare fallow soils", "model parametrization"]}, "links": [{"href": "https://air.unimi.it/bitstream/2434/809186/2/GCB-20-1834_Proof_fl.pdf"}, {"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.15441"}, {"href": "https://doi.org/10.1111/gcb.15441"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/gcb.15441", "name": "item", "description": "10.1111/gcb.15441", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/gcb.15441"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-11-24T00:00:00Z"}}, {"id": "1983/ab17d5ff-3657-42df-84a6-4ab038c16f20", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:26:41Z", "type": "Journal Article", "created": "2019-10-22", "title": "Which practices co\u2010deliver food security, climate change mitigation and adaptation, and combat land degradation and desertification?", "description": "AbstractThere is a clear need for transformative change in the land management and food production sectors to address the global land challenges of climate change mitigation, climate change adaptation, combatting land degradation and desertification, and delivering food security (referred to hereafter as \uffe2\uff80\uff9cland challenges\uffe2\uff80\uff9d). We assess the potential for 40 practices to address these land challenges and find that: Nine options deliver medium to large benefits for all four land challenges. A further two options have no global estimates for adaptation, but have medium to large benefits for all other land challenges. Five options have large mitigation potential (>3\uffc2\uffa0Gt CO2eq/year) without adverse impacts on the other land challenges. Five options have moderate mitigation potential, with no adverse impacts on the other land challenges. Sixteen practices have large adaptation potential (>25 million people benefit), without adverse side effects on other land challenges. Most practices can be applied without competing for available land. However, seven options could result in competition for land. A large number of practices do not require dedicated land, including several land management options, all value chain options, and all risk management options. Four options could greatly increase competition for land if applied at a large scale, though the impact is scale and context specific, highlighting the need for safeguards to ensure that expansion of land for mitigation does not impact natural systems and food security. A number of practices, such as increased food productivity, dietary change and reduced food loss and waste, can reduce demand for land conversion, thereby potentially freeing\uffe2\uff80\uff90up land and creating opportunities for enhanced implementation of other practices, making them important components of portfolios of practices to address the combined land challenges.10% of people on Earth) will experience severe food deficiencies by 2050. Increased production is urgently needed, but high costs and volatile prices are driving farmers into debt. Zero budget natural farming (ZBNF) is a grassroots movement that aims to improve farm viability by reducing costs. In Andhra Pradesh alone, 523,000 farmers have converted 13% of productive agricultural area to ZBNF. However, sustainability of ZBNF is questioned because external nutrient inputs are limited, which could cause a crash in food production. Here, we show that ZBNF is likely to reduce soil degradation and could provide yield benefits for low-input farmers. Nitrogen fixation, either by free-living nitrogen fixers in soil or symbiotic nitrogen fixers in legumes, is likely to provide the major portion of nitrogen available to crops. However, even with maximum potential nitrogen fixation and release, only 52-80% of the national average nitrogen applied as fertilizer is expected to be supplied. Therefore, in higher-input systems, yield penalties are likely. Since biological fixation from the atmosphere is possible only with nitrogen, ZBNF could limit the supply of other nutrients. Further research is needed in higher-input systems to ensure that mass conversion to ZBNF does not limit India's capacity to feed itself.", "keywords": ["Monitoring", "IEAS/POO2501/1", "NE/S009019/1", "330", "Supplementary Data", "QH301 Biology", "NE/P004830/1", "WHEAT", "01 natural sciences", "630", "12. Responsible consumption", "QH301", "NE/M021327/1", "SOIL PHYSICAL-PROPERTIES", "SDG 7 - Affordable and Clean Energy", "FERTILIZER", "Renewable Energy", "Wellcome Trust", "SDG 2 - Zero Hunger", "Nature and Landscape Conservation", "0105 earth and related environmental sciences", "Planning and Development", "2. Zero hunger", "Global and Planetary Change", "Geography", "Policy and Law", "Ecology", "Sustainability and the Environment", "Natural Environment Research Council (NERC)", "Sustainable and Healthy Food Systems (SHEFS)", "NE/P019455/1", "1. No poverty", "04 agricultural and veterinary sciences", "15. Life on land", "6. Clean water", "Management", "NITROGEN", "Urban Studies", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "INDIA", "Economic and Social Research Council (ESRC)", "Food Science"]}, "links": [{"href": "https://www.nature.com/articles/s41893-019-0469-x.pdf"}, {"href": "https://doi.org/2164/14738"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Nature%20Sustainability", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "2164/14738", "name": "item", "description": "2164/14738", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/2164/14738"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-01-20T00:00:00Z"}}, {"id": "2164/15915", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:27:02Z", "type": "Journal Article", "created": "2020-07-01", "title": "Global Research Alliance N2O chamber methodology guidelines: Summary of modeling approaches", "description": "Abstract
Measurements of nitrous oxide (N2O) emissions from agriculture are essential for understanding the complex soil\uffe2\uff80\uff93crop\uffe2\uff80\uff93climate processes, but there are practical and economic limits to the spatial and temporal extent over which measurements can be made. Therefore, N2O models have an important role to play. As models are comparatively cheap to run, they can be used to extrapolate field measurements to regional or national scales, to simulate emissions over long time periods, or to run scenarios to compare mitigation practices. Process\uffe2\uff80\uff90based models can also be used as an aid to understanding the underlying processes, as they can simulate feedbacks and interactions that can be difficult to distinguish in the field. However, when applying models, it is important to understand the conceptual process differences in models, how conceptual understanding changed over time in various models, and the model requirements and limitations to ensure that the model is well suited to the purpose of the investigation and the type of system being simulated. The aim of this paper is to give the reader a high\uffe2\uff80\uff90level overview of some of the important issues that should be considered when modeling. This includes conceptual understanding of widely used models, common modeling techniques such as calibration and validation, assessing model fit, sensitivity analysis, and uncertainty assessment. We also review examples of N2O modeling for different purposes and describe three commonly used process\uffe2\uff80\uff90based N2O models (APSIM, DayCent, and DNDC).There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international \uffe2\uff80\uff984p1000\uffe2\uff80\uff99 initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long\uffe2\uff80\uff90term experiments and space\uffe2\uff80\uff90for\uffe2\uff80\uff90time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.This study evaluates the dynamics of soil organic carbon (SOC) under perennial crops across the globe. It quantifies the effect of change from annual to perennial crops and the subsequent temporal changes in SOC stocks during the perennial crop cycle. It also presents an empirical model to estimate changes in the SOC content under crops as a function of time, land use, and site characteristics. We used a harmonized global dataset containing paired\uffe2\uff80\uff90comparison empirical values of SOC and different types of perennial crops (perennial grasses, palms, and woody plants) with different end uses: bioenergy, food, other bio\uffe2\uff80\uff90products, and short rotation coppice. Salient outcomes include: a 20\uffe2\uff80\uff90year period encompassing a change from annual to perennial crops led to an average 20% increase in SOC at 0\uffe2\uff80\uff9330\uffc2\uffa0cm (6.0\uffc2\uffa0\uffc2\uffb1\uffc2\uffa04.6\uffc2\uffa0Mg/ha gain) and a total 10% increase over the 0\uffe2\uff80\uff93100\uffc2\uffa0cm soil profile (5.7\uffc2\uffa0\uffc2\uffb1\uffc2\uffa010.9\uffc2\uffa0Mg/ha). A change from natural pasture to perennial crop decreased SOC stocks by 1% over 0\uffe2\uff80\uff9330\uffc2\uffa0cm (\uffe2\uff88\uff922.5\uffc2\uffa0\uffc2\uffb1\uffc2\uffa04.2\uffc2\uffa0Mg/ha) and 10% over 0\uffe2\uff80\uff93100\uffc2\uffa0cm (\uffe2\uff88\uff9213.6\uffc2\uffa0\uffc2\uffb1\uffc2\uffa08.9\uffc2\uffa0Mg/ha). The effect of a land use change from forest to perennial crops did not show significant impacts, probably due to the limited number of plots; but the data indicated that while a 2% increase in SOC was observed at 0\uffe2\uff80\uff9330\uffc2\uffa0cm (16.81\uffc2\uffa0\uffc2\uffb1\uffc2\uffa055.1\uffc2\uffa0Mg/ha), a decrease in 24% was observed at 30\uffe2\uff80\uff93100\uffc2\uffa0cm (\uffe2\uff88\uff9240.1\uffc2\uffa0\uffc2\uffb1\uffc2\uffa016.8\uffc2\uffa0Mg/ha). Perennial crops generally accumulate SOC through time, especially woody crops; and temperature was the main driver explaining differences in SOC dynamics, followed by crop age, soil bulk density, clay content, and depth. We present empirical evidence showing that the FAO perennialization strategy is reasonable, underscoring the role of perennial crops as a useful component of climate change mitigation strategies.Simulation models represent soil organic carbon (SOC) dynamics in global carbon (C) cycle scenarios to support climate\uffe2\uff80\uff90change studies. It is imperative to increase confidence in long\uffe2\uff80\uff90term predictions of SOC dynamics by reducing the uncertainty in model estimates. We evaluated SOC simulated from an ensemble of 26 process\uffe2\uff80\uff90based C models by comparing simulations to experimental data from seven long\uffe2\uff80\uff90term bare\uffe2\uff80\uff90fallow (vegetation\uffe2\uff80\uff90free) plots at six sites: Denmark (two sites), France, Russia, Sweden and the United Kingdom. The decay of SOC in these plots has been monitored for decades since the last inputs of plant material, providing the opportunity to test decomposition without the continuous input of new organic material. The models were run independently over multi\uffe2\uff80\uff90year simulation periods (from 28 to 80\uffc2\uffa0years) in a blind test with no calibration (Bln) and with the following three calibration scenarios, each providing different levels of information and/or allowing different levels of model fitting: (a) calibrating decomposition parameters separately at each experimental site (Spe); (b) using a generic, knowledge\uffe2\uff80\uff90based, parameterization applicable in the Central European region (Gen); and (c) using a combination of both (a) and (b) strategies (Mix). We addressed uncertainties from different modelling approaches with or without spin\uffe2\uff80\uff90up initialization of SOC. Changes in the multi\uffe2\uff80\uff90model median (MMM) of SOC were used as descriptors of the ensemble performance. On average across sites, Gen proved adequate in describing changes in SOC, with MMM equal to average SOC (and standard deviation) of 39.2 (\uffc2\uffb115.5)\uffc2\uffa0Mg\uffc2\uffa0C/ha compared to the observed mean of 36.0 (\uffc2\uffb119.7)\uffc2\uffa0Mg\uffc2\uffa0C/ha (last observed year), indicating sufficiently reliable SOC estimates. Moving to Mix (37.5\uffc2\uffa0\uffc2\uffb1\uffc2\uffa016.7\uffc2\uffa0Mg\uffc2\uffa0C/ha) and Spe (36.8\uffc2\uffa0\uffc2\uffb1\uffc2\uffa019.8\uffc2\uffa0Mg\uffc2\uffa0C/ha) provided only marginal gains in accuracy, but modellers would need to apply more knowledge and a greater calibration effort than in Gen, thereby limiting the wider applicability of models.