{"type": "FeatureCollection", "features": [{"id": "10.1016/j.soilbio.2004.08.013", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-21T16:16:09Z", "type": "Journal Article", "created": "2004-09-30", "title": "Decomposition Of C-14-Labeled Roots In A Pasture Soil Exposed To 10 Years Of Elevated Co2", "description": "Abstract   The net flux of soil C is determined by the balance between soil C input and microbial decomposition, both of which might be altered under prolonged elevated atmospheric CO 2 . In this study, we determined the effect of elevated CO 2  on decomposition of grass root material ( Lolium perenne  L.).  14 C-labeled root material, produced under ambient (35\u00a0Pa pCO 2 ) or elevated CO 2  (70\u00a0Pa pCO 2 ) was incubated in soil for 64 days. The soils were taken from a pasture ecosystem which had been exposed to ambient (35\u00a0Pa pCO 2 ) or elevated CO 2  (60\u00a0Pa pCO 2 ) under FACE-conditions for 10 years and two fertilizer N rates: 140 and 560\u00a0kg N ha \u22121 \u00a0year \u22121 . In soil exposed to elevated CO 2 , decomposition rates of root material grown at either ambient or elevated CO 2  were always lower than in the control soil exposed to ambient CO 2 , demonstrating a change in microbial activity. In the soil that received the high rate of N fertilizer, decomposition of root material grown at elevated CO 2  decreased by approximately 17% after incubation for 64 days compared to root material grown at ambient CO 2 . The amount of  14 CO 2  respired per amount of  14 C incorporated in the microbial biomass ( q  14 CO 2 ) was significantly lower when roots were grown under high CO 2  compared to roots grown under low CO 2 . We hypothesize that this decrease is the result of a shift in the microbial community, causing an increase in metabolic efficiency. Soils exposed to elevated CO 2  tended to respire more native SOC, both with and without the addition of the root material, probably resulting from a higher C supply to the soil during the 10 years of treatment with elevated CO 2 . The results show the importance of using soils adapted to elevated CO 2  in studies of decomposition of roots grown under elevated CO 2 . Our results further suggest that negative priming effects may obscure CO 2  data in incubation experiments with unlabeled substrates. From the results obtained, we conclude that a slower turnover of root material grown in an \u2018elevated-CO 2  world\u2019 may result in a limited net increase in C storage in ryegrass swards.", "keywords": ["organic-matter dynamics", "2. Zero hunger", "microbial biomass", "atmospheric carbon-dioxide", "turnover", "fine roots", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences", "forest soils", "tallgrass prairie", "trifolium-repens l", "lolium-perenne", "litter quality", "0401 agriculture", " forestry", " and fisheries", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.soilbio.2004.08.013"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Soil%20Biology%20and%20Biochemistry", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.soilbio.2004.08.013", "name": "item", "description": "10.1016/j.soilbio.2004.08.013", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.soilbio.2004.08.013"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2005-03-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2006.01172.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-21T16:17:40Z", "type": "Journal Article", "created": "2006-07-06", "title": "Total Soil C And N Sequestration In A Grassland Following 10 Years Of Free Air Co2 Enrichment", "description": "Abstract<p>Soil C sequestration may mitigate rising levels of atmospheric CO2. However, it has yet to be determined whether net soil C sequestration occurs in N\uffe2\uff80\uff90rich grasslands exposed to long\uffe2\uff80\uff90term elevated CO2. This study examined whether N\uffe2\uff80\uff90fertilized grasslands exposed to elevated CO2 sequestered additional C. For 10 years, Lolium perenne, Trifolium repens, and the mixture of L. perenne/T. repens grasslands were exposed to ambient and elevated CO2 concentrations (35 and 60\uffe2\uff80\uff83Pa pCO2). The applied CO2 was depleted in \uffce\uffb413C and the grasslands received low (140\uffe2\uff80\uff83kg\uffe2\uff80\uff83ha\uffe2\uff88\uff921) and high (560\uffe2\uff80\uff83kg\uffe2\uff80\uff83ha\uffe2\uff88\uff921) rates of 15N\uffe2\uff80\uff90labeled fertilizer. Annually collected soil samples from the top 10\uffe2\uff80\uff83cm of the grassland soils allowed us to follow the sequestration of new C in the surface soil layer. For the first time, we were able to collect dual\uffe2\uff80\uff90labeled soil samples to a depth of 75\uffe2\uff80\uff83cm after 10 years of elevated CO2 and determine the total amount of new soil C and N sequestered in the whole soil profile. Elevated CO2, N\uffe2\uff80\uff90fertilization rate, and species had no significant effect on total soil C. On average 9.4\uffe2\uff80\uff83Mg new C\uffe2\uff80\uff83ha\uffe2\uff88\uff921 was sequestered, which corresponds to 26.5% of the total C. The mean residence time of the C present in the 0\uffe2\uff80\uff9310\uffe2\uff80\uff83cm soil depth was calculated at 4.6\uffc2\uffb11.5 and 3.1\uffc2\uffb11.1 years for L. perenne and T. repens soil, respectively. After 10 years, total soil N and C in the 0\uffe2\uff80\uff9375\uffe2\uff80\uff83cm soil depth was unaffected by CO2 concentration, N\uffe2\uff80\uff90fertilization rate and plant species. The total amount of 15N\uffe2\uff80\uff90fertilizer sequestered in the 0\uffe2\uff80\uff9375\uffe2\uff80\uff83cm soil depth was also unaffected by CO2 concentration, but significantly more 15N was sequestered in the L. perenne compared with the T. repens swards: 620 vs. 452\uffe2\uff80\uff83kg\uffe2\uff80\uff83ha\uffe2\uff88\uff921 at the high rate and 234 vs. 133\uffe2\uff80\uff83kg\uffe2\uff80\uff83ha\uffe2\uff88\uff921 at the low rate of N fertilization. Intermediate values of 15N recovery were found in the mixture. The fertilizer derived N amounted to 2.8% of total N for the low rate and increased to 8.6% for the high rate of N application. On average, 13.9% of the applied 15N\uffe2\uff80\uff90fertilizer was recovered in the 0\uffe2\uff80\uff9375\uffe2\uff80\uff83cm soil depth in soil organic matter in the L. perenne sward, whereas 8.8% was recovered under the T. repens swards, indicating that the N2\uffe2\uff80\uff90fixing T. repens system was less effective in sequestering applied N than the non\uffe2\uff80\uff90N2\uffe2\uff80\uff90fixing L. perenne system. Prolonged elevated CO2 did not lead to an increase in whole soil profile C and N in these fertilized pastures. The potential use of fertilized and regular cut pastures as a net soil C sink under long\uffe2\uff80\uff90term elevated CO2 appears to be limited and will likely not significantly contribute to the mitigation of anthropogenic C emissions.</p>", "keywords": ["2. Zero hunger", "plant", "04 agricultural and veterinary sciences", "15. Life on land", "nitrogen pools", "carbon-dioxide", "forest soils", "trifolium-repens l", "lolium-perenne", "litter quality", "0401 agriculture", " forestry", " and fisheries", "n-15-labeled fertilizer", "organic-matter", "elevated atmospheric co2"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2006.01172.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.1365-2486.2006.01172.x", "name": "item", "description": "10.1111/j.1365-2486.2006.01172.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2006.01172.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-07-04T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=trifolium-repens+l&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=trifolium-repens+l&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=trifolium-repens+l&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=trifolium-repens+l&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-09-22T01:47:39.847375Z"}