Conversion of arable land (maize) to pasture will affect the soil organic matter (SOM) content. Changes in the SOM content were studied using a size- and density-fractionation method and C-13 analysis. Twenty-six years of maize cropping had resulted in a depletion of carbon stored in the macro-organic fractions (>150 mu m) and an increase in the 250 mu m), light (b.d. 150 mu m) and light (b.d. 150 mu m; b.d. >1.13 g cm(-3)) in the 0- to 20-cm layer was still 40-50% lower than in the continuous pasture plots. Average half-life times calculated from C-13 analyses ranged from 7 years in the light fractions to 56 years in heavy fractions. Fractionation results and C-13 data indicated that mechanical disturbance (plowing) during maize cropping had resulted in vertical displacement of dispersed soil carbon from the 0- to 20-cm layer down to 60-80 cm. Conversion of arable land to pasture, therefore, not only causes a regeneration of the soil carbon content, it also reduces the risk of contaminant transport by dispersed soil carbon.
", "keywords": ["land use change", "DECOMPOSITION", "2. Zero hunger", "C-13 analyses", "04 agricultural and veterinary sciences", "15. Life on land", "maize", "Maize", "C-13 NATURAL-ABUNDANCE", "CULTIVATION", "pasture", "13C analyses", "VERTISOLS", "SIZE", "SYSTEMS", "Pasture", "0401 agriculture", " forestry", " and fisheries", "Organic matter", "Fractionation", "fractionation", "Land use change", "CARBON TURNOVER", "FRACTIONS", "organic matter", "STORAGE"], "contacts": [{"organization": "R\u00f6mkens, P.F.A.M., van der Plicht, J., Hassink, J.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/s003740050494"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Biology%20and%20Fertility%20of%20Soils", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s003740050494", "name": "item", "description": "10.1007/s003740050494", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s003740050494"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1999-01-01T00:00:00Z"}}, {"id": "10.1023/b:plso.0000020975.75850.ca", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:17:15Z", "type": "Journal Article", "created": "2004-03-24", "title": "Isotopic Estimates Of New Carbon Inputs Into Litter And Soils In A Four-Year Climate Change Experiment With Douglas-Fir", "description": "Because soil is a major reservoir of terrestrial carbon and a potential sink for atmospheric CO2, determining plant inputs to soil carbon is critical for understanding ecosystem carbon dynamics. We present a modified method to quantify the effects of global climate change on plant inputs of carbon to soil based on 13C:12C ratio (\u03b413C) analyses that accounts for isotopic fractionation between inputs and newly created soil carbon. In a four-year study, the effects of elevated CO2 and temperature were determined for reconstructed Douglas-fir (Pseudotsuga mensiezii (Mirb.) Franco) ecosystems in which native soil of low nitrogen content was used. The \u03b413C patterns in litter and mineral soil horizons were measured and compared to \u03b413C patterns in live needles, fine roots, and coarse roots. From regression analyses, we calculated the isotopic enrichment in 13C of newly incorporated soil carbon relative to needle and root carbon at 4\u2030 and 2\u2030, respectively. These enrichments must be considered when using shifts in soil \u03b413C to calculate inputs of plant carbon into the soil, and are probably a major factor in the progressive enrichment in 13C with increasing depth in soil profiles. Relative to the total carbon in each layer, the proportion of new carbon from recent photosynthate in each soil layer was 13\u201315% in the A horizon, 7\u20139% in litter layers, and 4% in the B2 and C horizons. New carbon in the A horizon was estimated at 370\u00a0g C\u00a0m\u22122. Carbon concentrations and new carbon in A horizons were correlated (r 2=0.78, n=12), but with a slope of 0.356, indicating that about 36% of net carbon accumulation in the A horizon was from inputs via roots, root exudates or mycorrhizal fungi and 64% of carbon was derived from surface litter decomposition. Under the nitrogen-limited growth conditions used in this study, neither elevated CO2 nor temperature affected soil carbon sequestration patterns.", "keywords": ["elevated temperature", "13. Climate action", "soil carbon turnover", "elevated carbon dioxide", "stable isotopes", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "mesocosms", "15. Life on land", "global change", "isotopic discrimination"], "contacts": [{"organization": "Hobbie, Erik A., Johnson, M. G., Rygiewicz, Paul T., Tingey, David T., Olszyk, David M.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1023/b:plso.0000020975.75850.ca"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1023/b:plso.0000020975.75850.ca", "name": "item", "description": "10.1023/b:plso.0000020975.75850.ca", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1023/b:plso.0000020975.75850.ca"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-02-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2004.00883.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:18:29Z", "type": "Journal Article", "created": "2004-12-02", "title": "Carbon Flow In An Upland Grassland: Effect Of Liming On The Flux Of Recently Photosynthesized Carbon To Rhizosphere Soil", "description": "AbstractThe effect of liming on the flow of recently photosynthesized carbon to rhizosphere soil was studied using 13CO2 pulse labelling, in an upland grassland ecosystem in Scotland. The use of 13C enabled detection, in the field, of the effect of a 4\uffe2\uff80\uff90year liming period of selected soil plots on C allocation from plant biomass to soil, in comparison with unlimed plots. Photosynthetic rates and carbon turnover were higher in plants grown in limed soils than in those from unlimed plots. Higher \uffce\uffb413C\uffe2\uff80\uffb0 values were detected in shoots from limed plants than in those from unlimed plants in samples clipped within 15 days of the end of pulse labelling. Analysis of the aboveground plant production corresponding to the 4\uffe2\uff80\uff90year period of liming indicated that the standing biomass was higher in plots that received lime. Lower \uffce\uffb413C\uffe2\uff80\uffb0 values in limed roots compared with unlimed roots were found, whereas no significant difference was detected between soil samples. Extrapolation of our results indicated that more C has been lost through the soil than has been gained via photosynthetic assimilation because of pasture liming in Scotland during the period 1990\uffe2\uff80\uff931998. However, the uncertainty associated with such extrapolation based on this single study is high and these estimates are provided only to set our findings in the broader context of national soil carbon emissions.
", "keywords": ["2. Zero hunger", "/dk/atira/pure/subjectarea/asjc/2300/2306", "name=Global and Planetary Change", "/dk/atira/pure/subjectarea/asjc/2300/2304", "550", "rhizosphere soil", "liming", "04 agricultural and veterinary sciences", "15. Life on land", "630", "upland grassland", "name=Environmental Chemistry", "carbon pools", "name=Ecology", "0401 agriculture", " forestry", " and fisheries", "name=General Environmental Science", "carbon turnover", "/dk/atira/pure/subjectarea/asjc/2300/2303", "13C", "/dk/atira/pure/subjectarea/asjc/2300/2300"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2004.00883.x"}, {"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/j.1365-2486.2004.00883.x", "name": "item", "description": "10.1111/j.1365-2486.2004.00883.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2004.00883.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-12-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2009.02082.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:18:32Z", "type": "Journal Article", "created": "2009-09-24", "title": "Turnover Of Labile And Recalcitrant Soil Carbon Differ In Response To Nitrate And Ammonium Deposition In An Ombrotrophic Peatland", "description": "AbstractThe effects of 4 years of simulated nitrogen deposition, as nitrate (NO3\uffe2\uff88\uff92) and ammonium (NH4+), on microbial carbon turnover were studied in an ombrotrophic peatland. We investigated the mineralization of simple forms of carbon using MicroResp\uffe2\uff84\uffa2 measurements (a multiple substrate induced respiration technique) and the activities of four soil enzymes involved in the decomposition of more complex forms of carbon or in nutrient acquisition: N\uffe2\uff80\uff90acetyl\uffe2\uff80\uff90glucosaminidase (NAG), cellobiohydrolase (CBH), acid phosphatase (AP), and phenol oxidase (PO). The potential mineralization of labile forms of carbon was significantly enhanced at the higher N additions, especially with NH4+ amendments, while potential enzyme activities involved in breakdown of more complex forms of carbon or nutrient acquisition decreased slightly (NAG and CBH) or remained unchanged (AP and PO) with N amendments. This study also showed the importance of distinguishing between NO3\uffe2\uff88\uff92 and NH4+ amendments, as their impact often differed. It is possible that the limited response on potential extracellular enzyme activity is due to other factors, such as limited exposure to the added N in the deeper soil or continued suboptimal functioning of the enzymes due to the low pH, possibly via the inhibitory effect of low phenol oxidase activity.
", "keywords": ["nitrogen deposition", "Whim bog", "substrate-induced respiration", "0401 agriculture", " forestry", " and fisheries", "peatland", "Soil Biology", "04 agricultural and veterinary sciences", "Biological Sciences", "carbon turnover", "15. Life on land", "Environmental Sciences", "enzyme activity"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2009.02082.x"}, {"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/j.1365-2486.2009.02082.x", "name": "item", "description": "10.1111/j.1365-2486.2009.02082.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2009.02082.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-07-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2010.02196.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:18:32Z", "type": "Journal Article", "created": "2010-02-05", "title": "Nitrogen Deposition, Vegetation Burning And Climate Warming Act Independently On Microbial Community Structure And Enzyme Activity Associated With Decomposing Litter In Low-Alpine Heath", "description": "AbstractLow\uffe2\uff80\uff90alpine heathlands are thought to be particularly sensitive to nitrogen (N) deposition, climate and land management change, yet little is known about how these factors regulate key belowground processes, like litter turnover, under field conditions. Here we use an in situ factorial field experiment to test the effects of increased atmospheric N deposition, climate manipulation and past vegetation burning, and their interactions, on litter decomposition and the activity and diversity of associated microorganisms. The use of litter from within (native) and outwith (standard) the experimental plots also enabled us to test whether decomposition and microbial functional diversity is driven primarily by soil conditions or litter chemistry. In general, extracellular enzyme activities of litter were driven by additions of simulated N deposition with phosphatase being the most responsive. We found that standard litter incubated in plots that had been burnt 8 years previously decomposed slower and lost less N and phosphorus than in unburnt plots. This material also had associated with it the greatest activity of glucosidase and the least diverse microbial community, as assessed by culture\uffe2\uff80\uff90independent methods. Although all treatments significantly affected microbial diversity, burning explained most of the variability, indicating a close coupling between plant and microbial communities in these treatments. A striking feature of all the data relating to both standard and native litter was an almost complete lack of interactive effects between the treatments. The lack of interactions between the treatments indicates that each perturbation might affect different mechanisms in the decomposition process (including the composition of associated microbial communities) and nutrient cycling.
", "keywords": ["climate change", "enzyme activities", "soil microorganisms", "soil bacteria", "13. Climate action", "microbial diversity", "soil fungi", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "carbon turnover", "15. Life on land"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2010.02196.x"}, {"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/j.1365-2486.2010.02196.x", "name": "item", "description": "10.1111/j.1365-2486.2010.02196.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2010.02196.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-02-05T00:00:00Z"}}, {"id": "10.2307/1939339", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:20:08Z", "type": "Journal Article", "created": "2006-05-09", "title": "Soil Organic-Matter Dynamics Along Gradients In Temperature And Land-Use On The Island Of Hawaii", "description": "We studied soil organic matter (SOM) dynamics in allophanic soils (Udands) along independent gradients of temperature (altitude) and land use (forest\uffe2\uff80\uff94pasture) on the island of Hawaii. Using an integrated 13C signal derived from land conversion along with measurements of soil respiration and soil carbon, we separated rapid, intermediate, and very slow turnover SOM pools, and estimated turnover times for the large intermediate pool. These estimates were compared to independent estimates using either bomb\uffe2\uff80\uff94derived soil 14C or the Century soil organic matter model. All calculations based on a three\uffe2\uff80\uff94pool SOM structure yield rates of turnover that are 3 times slower than those produced by a single pool model. Accordingly, analyses of potential feedbacks between changes in climate, atmospheric CO2, and soil carbon should incorporate the heterogeneous nature of soil organic matter. We estimate that roughly three\uffe2\uff80\uff94quarters of the carbon in the top 20 cm of these soils has turnover times less than 30 yr. Turnover times for intermediate SOM double with a 10\uffc2\uffb0C change in mean annual temperature, suggesting that recalcitrant pools of SOM may be as sensitive to changes in temperature as the smaller labile pools.
", "keywords": ["2. Zero hunger", "13. Climate action", "organic matter dynamics", "land use", "temperature", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "carbon turnover", "15. Life on land", "USA", "Hawaii"], "contacts": [{"organization": "Susan E. Trumbore, Peter M. Vitousek, Alan R. Townsend, Alan R. Townsend,", "roles": ["creator"]}]}, "links": [{"href": "https://escholarship.org/content/qt8gg6f2vx/qt8gg6f2vx.pdf"}, {"href": "https://doi.org/10.2307/1939339"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2307/1939339", "name": "item", "description": "10.2307/1939339", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2307/1939339"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1995-04-01T00:00:00Z"}}, {"id": "10.5281/zenodo.14560239", "type": "Feature", "geometry": null, "properties": {"license": "unspecified", "updated": "2026-04-16T16:22:13Z", "type": "Dataset", "title": "Global maps of top- and subsoil organic carbon turnover times", "description": "This repository contains the dataset of the global maps of top- and subsoil organic carbon turnover times. More details can refer to the paper: Zhang, L., Yang, L., Crowther, T.W., Zohner, C.M., Doetterl, S., Heuvelink, G.B.M., Wadoux, A.M.J.-C., Zhu, A.-X., Pu, Y., Shen, F., Ma, H., Zou, Y., Zhou, C., 2025. Mapping global distributions, environmental controls, and uncertainties of apparent topsoil and subsoil organic carbon turnover times. Earth System Science Data 17, 2605\u20132623. DOI:\u00a0https://doi.org/10.5194/essd-17-2605-2025 \u00a0 The code used for the analyses in this study is available at:\u00a0https://github.com/leizhang-geo/global_soil_carbon_turnover_time.git For questions and more details of our study please contact the author: Lei Zhang (\u5f20\u78ca) LZ's Homepage: https://leizhang-geo.github.io", "keywords": ["carbon turnover time", "depth-dependent", "global carbon cycle", "soil carbon", "carbon sequestration", "edaphic-climate interactions"], "contacts": [{"organization": "Zhang, Lei", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5281/zenodo.14560239"}, {"rel": "self", "type": "application/geo+json", "title": "10.5281/zenodo.14560239", "name": "item", "description": "10.5281/zenodo.14560239", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5281/zenodo.14560239"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2025-01-01T00:00:00Z"}}, {"id": "10.5281/zenodo.16980274", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:22:43Z", "type": "Dataset", "title": "Ancient soil organic carbon quantification in worldwide soils", "description": "These are the files for the paper in press for Global Change Biology entitled ' Soil carbon dynamics reshaped by ancient carbon quantification'. The doi of this paper will be provided once the paper will be published. In this paper we applied a mixing linear equation to 313 soils worldwide from radiocarbon databases to estimate the ancient OC (radiocarbon-free) contained in these soils. Beyond the calculated contribution of this ancient OC to soil organic carbon (SOC) in top, sub and deepsoils, we revisited the mean 14C age of SOC and consequently the soil carbon dynamics. The \u201cCopard et al-GCB-data.xls\u201d file is split in two table. Table 1 is referred to the soil 14C ISRaD and LSCE database and additional variables we calculated in order to know the ancient organic carbon mass concentration in a considered soil profile and its contribution to the soil organic carbon for each soil layer. Some of these variables were either calculated by using the equations given in the associated article published in Global Change Biology (Copard et al) or derived from literature associated to the reference listed in the two databases (ISRaD and LSCE). Table 2 is identical to table 1 with additional variables devoted to loess formations, as the age of the loess deposit (BP), the organic carbon concentration from loess, and additional references with their doi where these specific variables were found. The Copard et al-GCB-readme.xls file consists in a summary file with your data explaining the variables used and entries in each row and column of the data file. This includes units of measurement, a description of each variable and explanation of how the files relate to each other.", "keywords": ["soil organic carbon", " radiocarbon", " carbon turnover time", " meta-analysis", " parent material", " radiocarbon-free organic carbon"], "contacts": [{"organization": "copard, yoann", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5281/zenodo.16980274"}, {"rel": "self", "type": "application/geo+json", "title": "10.5281/zenodo.16980274", "name": "item", "description": "10.5281/zenodo.16980274", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5281/zenodo.16980274"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2025-08-28T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=CARBON+TURNOVER&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=CARBON+TURNOVER&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=CARBON+TURNOVER&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=CARBON+TURNOVER&offset=8", "hreflang": "en-US"}], "numberMatched": 8, "numberReturned": 8, "distributedFeatures": [], "timeStamp": "2026-04-17T07:22:53.819169Z"}