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Emanuele Lugato - One of the best experts on this subject based on the ideXlab platform.
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low stabilization of aboveground crop residue carbon in sandy soils of swedish Long Term Experiments
Geoderma, 2015Co-Authors: Christophe Poeplau, Thomas Kattere, Marti A Olinde, Gunna Orjesso, Antonio Erti, Emanuele LugatoAbstract:Abstract Soil organic carbon (SOC) storage can be increased by incorporating crop residues such as straw. However, the use of straw as a bioenergy source is an alternative option. There is currently great uncertainty concerning the effects of residue incorporation/removal, but estimates can be improved by using well-documented, frequently sampled Long-Term Experiments (LTEs). This study examined the effect of straw incorporation on SOC stocks in six Swedish LTEs (duration of 27–56 years), using data from 5 to 28 sampling occasions. A total of 16 pairs of straw incorporation (SI) and straw removal (SR) treatments were compared and modelled with the ICBM/2 model (two young pools with distinct humification coefficients, h ), which enabled us to clearly isolate the effect of straw carbon input. The model results were compared to the Ultuna frame trial, as the first and only parameterization site of ICBM. At five out of six sites, the humification coefficient for straw ( h litter ) was much smaller (0–0.09) than the ICBM default h value for plant material (0.125). The derived h litter values and thus the stabilization of straw derived carbon increased significantly with clay content. An Italian site with five pairs of SI and SR treatments was used to test the performance of ICBM/2 under contrasting pedoclimatic conditions. Similar to the Swedish sites, the best model fits were found with h litter values ranging from 0 to 0.05 increasing with nitrogen fertilization (range of 0–240 kg N ha − 1 yr − 1 ), which was attributed to changes in substrate use efficiency of microbes. However, this trend was not consistent for all sites. For future applications of ICBM/2, we suggest using the validated clay function to derive h litter for common levels of nitrogen fertilization. The efficiency of incorporating straw to increase SOC stocks depends on soil texture and using it for bioenergy production could be a more sustainable and climate-smart option.
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modelling soil organic carbon dynamics in two Long Term Experiments of north eastern italy
Agriculture Ecosystems & Environment, 2007Co-Authors: Emanuele Lugato, Keith Paustian, L GiardiniAbstract:Simulation models are widely used to assess the impacts of management and environmental variables on soil organic matter dynamics, to address questions on ecosystem sustainability and carbon cycling under global change. We tested the Century ecosystem model for two Long-Term Experiments in north-eastern Italy: one (SF) comparing nutrient management treatments in small confined plots containing widely contrasting soil types (i.e., sandy, clay and peat) and the other (CR) involving a field study with crop rotation, nutrient, and management intensity variables. The organic matter changes in the SF experiment, showed a strong, linear relationship with C inputs from crop residues and added manures in the sand and clay soils, which was closely mimicked by the model. There was a net loss of soil C for all treatments in the peat soil, but the rate and overall magnitude of C losses were accurately simulated by the model, which suggested that treatment effects on soil C inputs was the major deTerminant of SOC dynamics in all three soils. In the CR experiment the model reasonably simulated the large initial decline (averaging about 30% of initial levels) in SOC observed in all treatments, as well as mean treatment effects over the course of the experiment. The model predicted a general pattern of higher SOC in the high management intensity, high fertility treatment combinations and lower SOC in the low management intensity, low fertility treatments; however, observed soil C did not show a clear pattern related to the treatments. Simulated soil C contents were linearly related to C input levels in the different treatments while there was no significant relationship between measured soil C and C inputs based on observed data.
P. R. Poulton - One of the best experts on this subject based on the ideXlab platform.
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major limitations to achieving 4 per 1000 increases in soil organic carbon stock in temperate regions evidence from Long Term Experiments at rothamsted research united kingdom
Global Change Biology, 2018Co-Authors: P. R. Poulton, Johnny Johnston, A J Macdonald, R P White, D S PowlsonAbstract:We evaluated the "4 per 1000" initiative for increasing soil organic carbon (SOC) by analysing rates of SOC increase in treatments in 16 Long-Term Experiments in southeast United Kingdom. The initiative sets a goal for SOC stock to increase by 4‰ per year in the 0-40 cm soil depth, continued over 20 years. Our Experiments, on three soil types, provided 114 treatment comparisons over 7-157 years. Treatments included organic additions (incorporated by inversion ploughing), N fertilizers, introducing pasture leys into continuous arable systems, and converting arable land to woodland. In 65% of cases, SOC increases occurred at >7‰ per year in the 0-23 cm depth, approximately equivalent to 4‰ per year in the 0-40 cm depth. In the two Longest running Experiments (>150 years), annual farmyard manure (FYM) applications at 35 t fresh material per hectare (equivalent to approx. 3.2 t organic C/ha/year) gave SOC increases of 18‰ and 43‰ per year in the 23 cm depth during the first 20 years. Increases exceeding 7‰ per year continued for 40-60 years. In other Experiments, with FYM applied at lower rates or not every year, there were increases of 3‰-8‰ per year over several decades. Other treatments gave increases between zero and 19‰ per year over various periods. We conclude that there are severe limitations to achieving the "4 per 1000" goal in practical agriculture over large areas. The reasons include (1) farmers not having the necessary resources (e.g. insufficient manure); (2) some, though not all, practices favouring SOC already widely adopted; (3) practices uneconomic for farmers-potentially overcome by changes in regulations or subsidies; (4) practices undesirable for global food security. We suggest it is more realistic to promote practices for increasing SOC based on improving soil quality and functioning as small increases can have disproportionately large beneficial impacts, though not necessarily translating into increased crop yield.
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organic geochemical studies of soils from the rothamsted classical Experiments v the fate of lipids in different Long Term Experiments
Organic Geochemistry, 2000Co-Authors: Ian D Bull, P. R. Poulton, Pim F Van Bergen, Chris J Nott, Richard P EvershedAbstract:Lipid extracts from four Long-Term Experiments (Broadbalk Wilderness, Geescroft Wilderness, Hoosfield Spring Barley and Park Grass) were analysed using a combination of gas chromatography, gas chromatography‐mass spectrometry and gas chromatography‐combustion‐isotope ratio mass spectrometry. The lipid content of the primary organic inputs for each soil werealso analysed inorder toassess the early diagenetic fate ofthe variouscompound classespresent.SoilpH was observed to, either directly or indirectly, have a significant eAect on lipids with a relative increase in abundance of n-alkanes at higher pH (7.31) and a large relative increase in n-alkanoic and o-hydroxy acids at low pH (3.74). Triacylglycerols exhibited severe losses irrespective of pH. In an arable soil, n-alkanoic acids showed a temporal decrease in concentration whilst levels of n-alkanols remained static, the diAerence was ascribed to a more rapid turnover and possible leachate migration of the n-alkanoic acids. The phytosterol, sitosterol, was observed to rapidly diminish in soils possibly as a result of assimilation by soil dwelling invertebrates. Analysis of 5b-stigmastanol (a faecal biomarker) showed that it remainedat levels indicativeofmanuringeven after 113 years. Furthermore, analysis of 5b-stanyl esters revealed a manuringsignal even more persistent than that exhibited by the free stanols. Knowledge of the biogeochemical cycling of lipids in the soil environment will help facilitate understanding of the processes which underpin carbon cycling in soils. # 2000 Elsevier Science Ltd. All rights reserved.
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Using the Long‐Term Experiments at rothamsted to address current agricultural and environmental issues
Archives of Agronomy and Soil Science, 1998Co-Authors: David S. Powlson, P. R. PoultonAbstract:In the Broadbalk Experiment at Rothamsted winter wheat has been grown in monoculture since 1843; wheat in rotation and additional treatments have been introduced during the course of the experiment. Since 1968, when new crop varieties and fungicides were introduced, yields have averaged over 6 t ha‐1with either inorganic fertilizers or farmyard manure. With high‐yielding varieties of winter wheat on Boardbalk, or spring barley on the Hoosfield experiment, maximum yields are currently achieved with a combination of inorganic and organic inputs. The Long‐Term Experiments have provided much information on the losses of nitrate and phosphate to water from different treatments and also on the impact of recent decreases of sulphur deposition on soil S dynamics and crop composition. Archived samples of soils and crops from the Park Grass Experiment (continuous cut pasture) and Experiments in which arable land has reverted to forest have provided information on soil acidification. This has resulted mainly from ac...
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simulating trends in soil organic carbon in Long Term Experiments using rothc 26 3
Geoderma, 1997Co-Authors: K Coleman, D. S. Jenkinson, Martin Körschens, P. R. Poulton, G.j. Crocker, P.r. Grace, J. Klír, Daniel RichterAbstract:Abstract As part of a model evaluation exercise, RothC-26.3, a model for the turnover of organic carbon in non-waterlogged soils, was fitted to measurements of organic carbon from 18 different experimental treatments on 6 Long-Term experimental sites in Germany, England, the USA, the Czech Republic and Australia. In the fitting process, the model was first run with an annual return of plant C that had been selected iteratively to give the carbon content of the soil at the start of each experiment. This was done for the soil and climate of each site. If the radiocarbon content of the soil organic matter was known, the inert organic carbon (IOM) content of the soil was also calculated for the start of the experiment. Using these carbon and radiocarbon contents as a starting point, the model was then run for each of the experimental treatments to be fitted, using iteratively selected values for the annual return of plant materials to the soil. The value used for each treatment was selected to optimise the fit between modelled and measured data over the whole experimental period: fitting was done by eye. Thus fitted, RothC-26.3 gave an acceptable approximation to the measurements for 14 of the treatments, bearing in mind the experimental errors in measuring soil organic carbon on a per hectare basis. With four of the treatments (Highfield Bare Fallow, Park Grass plot 13d, Ruzyně farmyard manure plot and Tamworth rotation 5), the fit was less satisfactory.
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simulating trends in soil organic carbon in Long Term Experiments using the century model
Geoderma, 1997Co-Authors: Robin Kelly, Martin Körschens, P. R. Poulton, G.j. Crocker, J. Klír, William J Parton, P R Graced, Daniel RichterAbstract:Abstract This paper describes Century Soil Organic Matter (SOM) Model simulations of seven Long-Term data sets that are the subject of this special issue. We found that Century successfully simulates SOM C across a variety of land use and climate types. Simulations of SOM were most successful in grass and crop systems. This exercise highlights a structural limitation of Century in simulating SOM in a forest with a developed litter layer. Simulations of tree biomass distributions, however, were generally successful. The model failed to capture extreme values of yield and N offtake, although annual averages were quite similar between observations and simulations, leading to reasonable estimates of SOM C. Average yields and SOM were generally higher in amended treatments or rotations including an N-fixing component such as alfalfa. The model successfully predicted SOM dynamics across climates, land use types, and treatments. This suggests that Century is a useful tool for ecosystem studies, particularly those focused on SOM dynamics.
Martin Körschens - One of the best experts on this subject based on the ideXlab platform.
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The evaluation of changes in soil humic substances composition and their nature in Long-Term Experiments of Germany and Russia
Archives of Agronomy and Soil Science, 2003Co-Authors: Nailia Habibovna Ismagilova, Martin KörschensAbstract:The results of investigation of soil organic matter (SOM), its mobile and more strongly bound forms in Long-Term Experiments on loamy soddy podzolic and grey soils of Russia and Loess-Chernozem of the Static Fertilization Experiment at Bad Lauchstadt in Germany are presented. The method of fractionation using successively 0.1 n sodium hydroxide (fraction 1), the mixture 0.1 m sodium pyrophosphate (fraction 2) and finally 0.02 n sodium hydroxide extraction on water bath (fraction 3) has been applied for isolation of humic substances differently bound with mineral part of soil. The results show that mineral and organic fertilizers differ in their effect on the composition of humic substances. The above mentioned properties of bound SOM fractions may possibly serve as indicators of manuring intensity and accumulation of decomposable SOM in dark soils of temperate climatic conditions initially characterized by predominance of humic substances with high optical density. The results show the importance of an op...
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EuroSOMNET – a European database of Long-Term Experiments on soil organic matter: the WWW metadatabase
The Journal of Agricultural Science, 2002Co-Authors: Pete Smith, Viktoria Rodionova, Martin Körschens, Kevin Coleman, Ludmila Shevtsova, V. Romanenkov, P. d. Falloon, U. Franko, J. u. Smith, G. SchrammAbstract:Since 1997, the EuroSOMNET project, funded by the EU-ENRICH programme, has assembled a metadatabase, and separate experimental databases, of European Long-Term Experiments that investigate changes in soil organic matter. In this paper, we describe the WWW-based metadatabase, which is a product of this project. The database holds detailed records of 110 Long-Term soil organic matter Experiments, giving a wide geographical coverage of Europe, and includes Experiments from the European part of the former Soviet Union, many of which have not been available previously. For speed of access, records are stored as hyper-text mark-up language (HTML) files. In this paper, we describe the metadatabase, the Experiments for which records are held, the information stored about each experiment, and summarize the main characteristics of these Experiments. Details from the metadatabase have already been used to examine regional trends in soil organic matter in Germany and eastern Europe, to construct and calibrate a regional statistical model of humus balance in Russia, to examine the effects of climatic conditions on soil organic matter dynamics, to estimate the potential for carbon sequestration in agricultural soils in Europe, and to test and improve soil organic matter models. The EuroSOMNET metadatabase provides information applicable to a wide range of agricultural and environmental questions and can be accessed freely via the EuroSOMNET home page at URL: http://www.iacr.bbsrc.ac.uk/aen/eusomnet/index.htm.
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EuroSOMNET—a database for Long-Term Experiments on soil organic matter in Europe
Computers and Electronics in Agriculture, 2002Co-Authors: Uwe Franko, Vladimir Romanenkov, Guido Schramm, Viktoria Rodionova, Martin Körschens, Pete Smith, Kevin Coleman, Ludmila ShevtsovaAbstract:Abstract Long-Term Experiments are usually connected with a large volume of data published in many different papers. Centralised storage of information in the form of databases is a suitable way to make the data more accessible for possible users. Although a collection of metadata exists on Long-Term Experiments in Europe, related to the turnover of soil organic matter, a convenient method to access the actual data was required. The EuroSOMNET database has been designed in order to save detailed information from those Experiments. The data model contains five pools of information: basics, climate, soil information, field management and results. Dataholders decide on the state of accessibility of their dataset (related to each experiment). Possible states range from private (access only for dataholders) to public (access to all Internet users). The most important advantages of this system are a standardised yet flexible data structure that facilitates the data exchange between different users. At this time there are 25 Experiments at different states of data processing stored. The sites extend from Russia to Great Britain. Land use systems contained are arable systems, grassland, bare fallow and vegetable production.
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EuroSOMNET – a European database of Long-Term Experiments on soil organic matter: the WWW metadatabase
The Journal of Agricultural Science, 2002Co-Authors: Pete Smith, Uwe Franko, Vladimir Romanenkov, Viktoria Rodionova, Martin Körschens, Kevin Coleman, Pete Falloon, L. K. Shevtsova, Jo Smith, G. SchrammAbstract:Since 1997, the EuroSOMNET project, funded by the EU-ENRICH programme, has assembled a metadatabase, and separate experimental databases, of European Long-Term Experiments that investigate changes in soil organic matter. In this paper, we describe the WWW-based metadatabase, which is a product of this project. The database holds detailed records of 110 Long-Term soil organic matter Experiments, giving a wide geographical coverage of Europe, and includes Experiments from the European part of the former Soviet Union, many of which have not been available previously. For speed of access, records are stored as hyper-text mark-up language (HTML) files. In this paper, we describe the metadatabase, the Experiments for which records are held, the information stored about each experiment, and summarize the main characteristics of these Experiments. Details from the metadatabase have already been used to examine regional trends in soil organic matter in Germany and eastern Europe, to construct and calibrate a regional statistical model of humus balance in Russia, to examine the effects of climatic conditions on soil organic matter dynamics, to estimate the potential for carbon sequestration in agricultural soils in Europe, and to test and improve soil organic matter models. The EuroSOMNET metadatabase provides information applicable to a wide range of agricultural and environmental questions and can be accessed freely via the EuroSOMNET home page at URL: http://www.iacr.bbsrc.ac.uk/aen/eusomnet/index.htm.
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EuroSOMNET - a database for Long-Term Experiments on soil organic matter in Europe
Computers and Electronics in Agriculture, 2002Co-Authors: Uwe Franko, Guido Schramm, Viktoria Rodionova, Martin Körschens, Pete Smith, Kevin Coleman, V. Romanenkov, Ludmila ShevtsovaAbstract:Abstract Long-Term Experiments are usually connected with a large volume of data published in many different papers. Centralised storage of information in the form of databases is a suitable way to make the data more accessible for possible users. Although a collection of metadata exists on Long-Term Experiments in Europe, related to the turnover of soil organic matter, a convenient method to access the actual data was required. The EuroSOMNET database has been designed in order to save detailed information from those Experiments. The data model contains five pools of information: basics, climate, soil information, field management and results. Dataholders decide on the state of accessibility of their dataset (related to each experiment). Possible states range from private (access only for dataholders) to public (access to all Internet users). The most important advantages of this system are a standardised yet flexible data structure that facilitates the data exchange between different users. At this time there are 25 Experiments at different states of data processing stored. The sites extend from Russia to Great Britain. Land use systems contained are arable systems, grassland, bare fallow and vegetable production.
Paul R. Poulton - One of the best experts on this subject based on the ideXlab platform.
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The electronic Rothamsted Archive (e-RA): an online resource for data from the Rothamsted Long-Term Experiments
Scientific Data, 2018Co-Authors: S. A. M. Perryman, Margaret J. Glendining, Paul R. Poulton, Nathalie Castells-brooke, Keith Goulding, Malcolm J. Hawkesford, Andy Macdonald, Richard Ostler, Christopher J. Rawlings, Tony ScottAbstract:The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted Long-Term Experiments
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The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted Long-Term Experiments
Scientific Data, 2018Co-Authors: S. A. M. Perryman, Margaret J. Glendining, Paul R. Poulton, Nathalie Castells-brooke, Malcolm J. Hawkesford, Richard Ostler, Christopher J. Rawlings, Keith W. T. Goulding, Andy J. Macdonald, Tony ScottAbstract:The electronic Rothamsted Archive, e-RA ( www.era.rothamsted.ac.uk ) provides a permanent managed database to both securely store and disseminate data from Rothamsted Research’s Long-Term field Experiments (since 1843) and meteorological stations (since 1853). Both historical and contemporary data are made available via this online database which provides the scientific community with access to a unique continuous record of agricultural Experiments and weather measured since the mid-19^th century. Qualitative information, such as treatment and management practices, plans and soil information, accompanies the data and are made available on the e-RA website. e-RA was released externally to the wider scientific community in 2013 and this paper describes its development, content, curation and the access process for data users. Case studies illustrate the diverse applications of the data, including its original intended purposes and recent unforeseen applications. Usage monitoring demonstrates the data are of increasing interest. Future developments, including adopting FAIR data principles, are proposed as the resource is increasingly recognised as a unique archive of data relevant to sustainable agriculture, agroecology and the environment.
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The importance of Long-Term Experiments in agriculture: their management to ensure continued crop production and soil fertility; the Rothamsted experience.
European Journal of Soil Science, 2018Co-Authors: A. E. Johnston, Paul R. PoultonAbstract:Summary Long‐Term field Experiments that test a range of treatments and are intended to assess the sustainability of crop production, and thus food security, must be managed actively to identify any treatment that is failing to maintain or increase yields. Once identified, carefully considered changes can be made to the treatment or management, and if they are successful yields will change. If suitable changes cannot be made to an experiment to ensure its continued relevance to sustainable crop production, then it should be stopped. Long‐Term Experiments have many other uses. They provide a field resource and samples for research on plant and soil processes and properties, especially those properties where change occurs slowly and affects soil fertility. Archived samples of all inputs and outputs are an invaluable source of material for future research, and data from current and archived samples can be used to develop models to describe soil and plant processes. Such changes and uses in the Rothamsted Experiments are described, and demonstrate that with the appropriate crop, soil and management, acceptable yields can be maintained for many years, with either organic manure or inorganic fertilizers. Highlights Long‐Term Experiments demonstrate sustainability and increases in crop yield when managed to optimize soil fertility. Shifting individual response curves into coincidence increases understanding of the factors involved. Changes in inorganic and organic pollutants in archived crop and soil samples are related to inputs over time. Models describing soil processes are developed from current and archived soil data.
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The importance of Long‐Term Experiments in agriculture: their management to ensure continued crop production and soil fertility; the Rothamsted experience
European Journal of Soil Science, 2018Co-Authors: A. E. Johnston, Paul R. PoultonAbstract:Summary Long‐Term field Experiments that test a range of treatments and are intended to assess the sustainability of crop production, and thus food security, must be managed actively to identify any treatment that is failing to maintain or increase yields. Once identified, carefully considered changes can be made to the treatment or management, and if they are successful yields will change. If suitable changes cannot be made to an experiment to ensure its continued relevance to sustainable crop production, then it should be stopped. Long‐Term Experiments have many other uses. They provide a field resource and samples for research on plant and soil processes and properties, especially those properties where change occurs slowly and affects soil fertility. Archived samples of all inputs and outputs are an invaluable source of material for future research, and data from current and archived samples can be used to develop models to describe soil and plant processes. Such changes and uses in the Rothamsted Experiments are described, and demonstrate that with the appropriate crop, soil and management, acceptable yields can be maintained for many years, with either organic manure or inorganic fertilizers. Highlights Long‐Term Experiments demonstrate sustainability and increases in crop yield when managed to optimize soil fertility. Shifting individual response curves into coincidence increases understanding of the factors involved. Changes in inorganic and organic pollutants in archived crop and soil samples are related to inputs over time. Models describing soil processes are developed from current and archived soil data.
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The Effectiveness of Nitrogen Derived from Organic Matter: Results from Long-Term Experiments
Plant Nutrient Acquisition, 2001Co-Authors: Paul R. PoultonAbstract:All agricultural systems make use of nitrogen derived from organic matter. Long-Term Experiments like those at Rothamsted have been used to quantify the effectiveness with which that N is used.
Pete Smith - One of the best experts on this subject based on the ideXlab platform.
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Simulating SOC changes in Long‐Term Experiments with RothC and CENTURY: model evaluation for a regional scale application
Soil Use and Management, 2006Co-Authors: Pete Falloon, Pete SmithAbstract:Predictive, regional use of soil organic matter (SOM) models requires evaluation of the performance of models with datasets from Long-Term Experiments relevant to the scenarios of interest to the regional scale study, and relevant to the climate of the study region. Datasets from six Long-Term Experiments were used to evaluate the performance of RothC and CENTURY, two of the most widely used and tested SOM models. Three types of model run were completed for each site: (1) CENTURY model alone; (2) RothC model run to fit measured SOC values, by iteratively adjusting C inputs to soil; and (3) RothC model run using C inputs derived from CENTURY runs. In general, the performance of both models was good across all datasets. The runs using RothC (iteratively changing C inputs to fit measured SOC values) tended to have the best fit to model data, since this method involved direct fitting to observed data. Carbon inputs estimated by RothC were, in general, lower than those estimated by CENTURY, since SOC in CENTURY tends to turn over faster than SOC in RothC. The runs using RothC with CENTURY C inputs tended to have the poorest fit of all, since CENTURY predicted greater C inputs than were required by RothC to maintain the same SOC content. A plausible model fit to measured SOC data may be obtained with widely differing C input values, due to differences in predicted decomposition rates between models. It remains unclear which, if either, modelling approach most closely represents reality since both C inputs to soil and decomposition rates for bulk SOM are difficult to deTermine experimentally. Further progress in SOM modelling can only be the result of research leading to better process understanding, both of net C inputs to soil and of SOM decomposition rates. The use of default methods for estimating initial SOC pools in RothC and CENTURY may not always be appropriate and may require adjustment for specific sites. The simulations presented here also suggest details of SOC dynamics not shown by available measured data, especially trends between sampling intervals, and this emphasizes the importance of archived soil samples in Long-Term Experiments.
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Simulating SOC changes in Long-Term Experiments with RothC and CENTURY: model evaluation for a regional scale application
Soil Use and Management, 2006Co-Authors: Pete Falloon, Pete SmithAbstract:Predictive, regional use of soil organic matter (SOM) models requires evaluation of the performance of models with datasets from Long-Term Experiments relevant to the scenarios of interest to the regional scale study, and relevant to the climate of the study region. Datasets from six Long-Term Experiments were used to evaluate the performance of RothC and CENTURY, two of the most widely used and tested SOM models. Three types of model run were completed for each site: (1) CENTURY model alone; (2) RothC model run to fit measured SOC values, by iteratively adjusting C inputs to soil; and (3) RothC model run using C inputs derived from CENTURY runs. In general, the performance of both models was good across all datasets. The runs using RothC (iteratively changing C inputs to fit measured SOC values) tended to have the best fit to model data, since this method involved direct fitting to observed data. Carbon inputs estimated by RothC were, in general, lower than those estimated by CENTURY, since SOC in CENTURY tends to turn over faster than SOC in RothC. The runs using RothC with CENTURY C inputs tended to have the poorest fit of all, since CENTURY predicted greater C inputs than were required by RothC to maintain the same SOC content. A plausible model fit to measured SOC data may be obtained with widely differing C input values, due to differences in predicted decomposition rates between models. It remains unclear which, if either, modelling approach most closely represents reality since both C inputs to soil and decomposition rates for bulk SOM are difficult to deTermine experimentally. Further progress in SOM modelling can only be the result of research leading to better process understanding, both of net C inputs to soil and of SOM decomposition rates. The use of default methods for estimating initial SOC pools in RothC and CENTURY may not always be appropriate and may require adjustment for specific sites. The simulations presented here also suggest details of SOC dynamics not shown by available measured data, especially trends between sampling intervals, and this emphasizes the importance of archived soil samples in Long-Term Experiments.
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EuroSOMNET – a European database of Long-Term Experiments on soil organic matter: the WWW metadatabase
The Journal of Agricultural Science, 2002Co-Authors: Pete Smith, Viktoria Rodionova, Martin Körschens, Kevin Coleman, Ludmila Shevtsova, V. Romanenkov, P. d. Falloon, U. Franko, J. u. Smith, G. SchrammAbstract:Since 1997, the EuroSOMNET project, funded by the EU-ENRICH programme, has assembled a metadatabase, and separate experimental databases, of European Long-Term Experiments that investigate changes in soil organic matter. In this paper, we describe the WWW-based metadatabase, which is a product of this project. The database holds detailed records of 110 Long-Term soil organic matter Experiments, giving a wide geographical coverage of Europe, and includes Experiments from the European part of the former Soviet Union, many of which have not been available previously. For speed of access, records are stored as hyper-text mark-up language (HTML) files. In this paper, we describe the metadatabase, the Experiments for which records are held, the information stored about each experiment, and summarize the main characteristics of these Experiments. Details from the metadatabase have already been used to examine regional trends in soil organic matter in Germany and eastern Europe, to construct and calibrate a regional statistical model of humus balance in Russia, to examine the effects of climatic conditions on soil organic matter dynamics, to estimate the potential for carbon sequestration in agricultural soils in Europe, and to test and improve soil organic matter models. The EuroSOMNET metadatabase provides information applicable to a wide range of agricultural and environmental questions and can be accessed freely via the EuroSOMNET home page at URL: http://www.iacr.bbsrc.ac.uk/aen/eusomnet/index.htm.
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EuroSOMNET—a database for Long-Term Experiments on soil organic matter in Europe
Computers and Electronics in Agriculture, 2002Co-Authors: Uwe Franko, Vladimir Romanenkov, Guido Schramm, Viktoria Rodionova, Martin Körschens, Pete Smith, Kevin Coleman, Ludmila ShevtsovaAbstract:Abstract Long-Term Experiments are usually connected with a large volume of data published in many different papers. Centralised storage of information in the form of databases is a suitable way to make the data more accessible for possible users. Although a collection of metadata exists on Long-Term Experiments in Europe, related to the turnover of soil organic matter, a convenient method to access the actual data was required. The EuroSOMNET database has been designed in order to save detailed information from those Experiments. The data model contains five pools of information: basics, climate, soil information, field management and results. Dataholders decide on the state of accessibility of their dataset (related to each experiment). Possible states range from private (access only for dataholders) to public (access to all Internet users). The most important advantages of this system are a standardised yet flexible data structure that facilitates the data exchange between different users. At this time there are 25 Experiments at different states of data processing stored. The sites extend from Russia to Great Britain. Land use systems contained are arable systems, grassland, bare fallow and vegetable production.
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EuroSOMNET – a European database of Long-Term Experiments on soil organic matter: the WWW metadatabase
The Journal of Agricultural Science, 2002Co-Authors: Pete Smith, Uwe Franko, Vladimir Romanenkov, Viktoria Rodionova, Martin Körschens, Kevin Coleman, Pete Falloon, L. K. Shevtsova, Jo Smith, G. SchrammAbstract:Since 1997, the EuroSOMNET project, funded by the EU-ENRICH programme, has assembled a metadatabase, and separate experimental databases, of European Long-Term Experiments that investigate changes in soil organic matter. In this paper, we describe the WWW-based metadatabase, which is a product of this project. The database holds detailed records of 110 Long-Term soil organic matter Experiments, giving a wide geographical coverage of Europe, and includes Experiments from the European part of the former Soviet Union, many of which have not been available previously. For speed of access, records are stored as hyper-text mark-up language (HTML) files. In this paper, we describe the metadatabase, the Experiments for which records are held, the information stored about each experiment, and summarize the main characteristics of these Experiments. Details from the metadatabase have already been used to examine regional trends in soil organic matter in Germany and eastern Europe, to construct and calibrate a regional statistical model of humus balance in Russia, to examine the effects of climatic conditions on soil organic matter dynamics, to estimate the potential for carbon sequestration in agricultural soils in Europe, and to test and improve soil organic matter models. The EuroSOMNET metadatabase provides information applicable to a wide range of agricultural and environmental questions and can be accessed freely via the EuroSOMNET home page at URL: http://www.iacr.bbsrc.ac.uk/aen/eusomnet/index.htm.
