{"type": "FeatureCollection", "features": [{"id": "10.1007/s10533-015-0157-5", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:20Z", "type": "Journal Article", "created": "2015-11-14", "title": "Chronic Nitrogen Fertilization And Carbon Sequestration In Grassland Soils: Evidence Of A Microbial Enzyme Link", "description": "Chronic nitrogen (N) fertilization can greatly affect soil carbon (C) sequestration by altering biochemical interactions between plant detritus and soil microbes. In lignin-rich forest soils, chronic N additions tend to increase soil C content partly by decreasing the activity of lignin-degrading enzymes. In cellulose-rich grassland soils it is not clear whether cellulose-degrading enzymes are also inhibited by N additions and what consequences this might have on changes in soil C content. Here we address whether chronic N fertilization has affected (1) the C content of light versus heavier soil fractions, and (2) the activity of four extracellular enzymes including the C-acquiring enzyme \u03b2-1,4-glucosidase (BG; necessary for cellulose hydrolysis). We found that 19\u00a0years of chronic N-only addition to permanent grassland have significantly increased soil C sequestration in heavy but not in light soil density fractions, and this C accrual was associated with a significant increase (and not decrease) of BG activity. Chronic N fertilization may increase BG activity because greater N availability reduces root C:N ratios thus increasing microbial demand for C, which is met by C inputs from enhanced root C pools in N-only fertilized soils. However, BG activity and total root mass strongly decreased in high pH soils under the application of lime (i.e. CaCO3), which reduced the ability of these organo-mineral soils to gain more C per units of N added. Our study is the first to show a potential \u2018enzyme link\u2019 between (1) long-term additions of inorganic N to grassland soils, and (2) the greater C content of organo-mineral soil fractions. Our new hypothesis is that the \u2018enzyme link\u2019 occurs because (a) BG activity is stimulated by increased microbial C demand relative to N under chronic fertilization, and (b) increased BG activity causes more C from roots and from microbial metabolites to accumulate and stabilize into organo-mineral C fractions. We suggest that any combination of management practices that can influence the BG \u2018enzyme link\u2019 will have far reaching implications for long-term C sequestration in grassland soils.", "keywords": ["DECOMPOSITION", "DYNAMICS", "570", "\u03b2-1", "4-Glucosidase", "/dk/atira/pure/subjectarea/asjc/2300/2304", "NUTRIENT RELEASE", "Environmental Sciences & Ecology", "Root C:N ratio", "Extracellular enzyme activity", "LITTER DECAY", "FOREST ECOSYSTEMS", "0399 Other Chemical Sciences", "0402 Geochemistry", "Environmental Chemistry", "Geosciences", " Multidisciplinary", "beta-1", "4-Glucosidase", "Earth-Surface Processes", "Water Science and Technology", "2. Zero hunger", "Multidisciplinary", "Science & Technology", "/dk/atira/pure/subjectarea/asjc/1900/1904", "Geology", "sequestration", "Agronomy & Agriculture", "04 agricultural and veterinary sciences", "15. Life on land", "Soil carbon", "N DEPOSITION", "ORGANIC-MATTER", "PHOSPHORUS", "Fertilization", "Physical Sciences", "N ratio [Root C]", "0401 agriculture", " forestry", " and fisheries", "Soil carbon sequestration", "Liming", "TURNOVER", "Life Sciences & Biomedicine", "Geosciences", "/dk/atira/pure/subjectarea/asjc/2300/2312", "Environmental Sciences", "RESPONSES"]}, "links": [{"href": "https://doi.org/10.1007/s10533-015-0157-5"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Biogeochemistry", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s10533-015-0157-5", "name": "item", "description": "10.1007/s10533-015-0157-5", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10533-015-0157-5"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2015-11-14T00:00:00Z"}}, {"id": "10.1007/s11368-011-0382-z", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:42Z", "type": "Journal Article", "created": "2011-05-23", "title": "In Situ Phytoremediation Of Pah-Contaminated Soil By Intercropping Alfalfa (Medicago Sativa L.) With Tall Fescue (Festuca Arundinacea Schreb.) And Associated Soil Microbial Activity", "description": "Purpose  A 7-month field experiment was conducted to investigate the polycyclic aromatic hydrocarbon (PAH) remediation potential of two plant species and changes in counts of soil PAH-degrading bacteria and microbial activity.", "keywords": ["2. Zero hunger", "/dk/atira/pure/subjectarea/asjc/1900/1904", "Stratigraphy", "/dk/atira/pure/subjectarea/asjc/1900/1913", "15. Life on land", "01 natural sciences", "6. Clean water", "Earth-Surface Processes", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1007/s11368-011-0382-z"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Soils%20and%20Sediments", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11368-011-0382-z", "name": "item", "description": "10.1007/s11368-011-0382-z", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11368-011-0382-z"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2011-05-24T00:00:00Z"}}, {"id": "10.2136/sssaj2000.642754x", "type": "Feature", "geometry": null, "properties": {"license": "Closed Access", "updated": "2026-06-23T16:21:03Z", "type": "Journal Article", "created": "2010-07-27", "title": "Response Of Surface Horizons In An Oak Forest To Prescribed Burning", "description": "<p>The reduction of forest floor ground cover and litter layers by prescribed fires may alter the morphology (field and micro) and physical properties of surface horizons. This study determined long\uffe2\uff80\uff90term (35 yr) changes in surface horizon bulk density, organic matter concentration and content, and morphology in response to periodic (5 yr) and annual (1 yr) prescribed fires. Soils were fine\uffe2\uff80\uff90silty, siliceous, thermic Glossic Fragiuldults, supporting mixed oak vegetation in middle Tennessee. Upper mineral soils (0\uffe2\uff80\uff90 to 2\uffe2\uff80\uff90cm and 0\uffe2\uff80\uff90 to 7.6\uffe2\uff80\uff90cm depths) were sampled and detailed field descriptions made. Periodic and control plots had a thin layer of Oi, Oe, and Oa horizons 5 yr after the 1993 burn, whereas on annual burn plots a 1\uffe2\uff80\uff90 to 2\uffe2\uff80\uff90cm charred layer was present. Significant reductions in organic matter concentration and mean thickness of the A horizon were found from burning (A horizons thicknesses were 6.4, 4.6, and 2.9 cm in control, periodic, and annual plots, respectively). Periodic burns did not significantly alter the organic matter and bulk density of the upper 7.6 cm of mineral soil; however, annual burns did result in significantly higher bulk densities (1.01, 1.07, and 1.29 Mg m\uffe2\uff88\uff923 in control, periodic, and annual plots, respectively) and lower organic matter concentrations and contents. Microscopic investigations confirmed that compaction was increased from annual burning. Thin sections also revealed that the granular structure of the A horizons in control and periodic plots resulted from bioterbation of macro and mesofauna, fungi, and roots. Long\uffe2\uff80\uff90term annual burning greatly affected surface soil properties, whereas periodic burning on a 5\uffe2\uff80\uff90yr cycle had only limited effects.</p>", "keywords": ["/dk/atira/pure/subjectarea/asjc/1100/1111", "name=Soil Science", "/dk/atira/pure/subjectarea/asjc/1900/1904", "name=Earth-Surface Processes", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "15. Life on land"], "contacts": [{"organization": "Phillips, Debra, Foss, J.E., Buckner, E.R., Evans, R.M., FitzPatrick, E.A.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.2136/sssaj2000.642754x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Soil%20Science%20Society%20of%20America%20Journal", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2136/sssaj2000.642754x", "name": "item", "description": "10.2136/sssaj2000.642754x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2136/sssaj2000.642754x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2000-03-01T00:00:00Z"}}, {"id": "10.5194/bg-8-2341-2011", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-23T16:22:30Z", "type": "Journal Article", "created": "2011-05-25", "title": "Nitrogen Enrichment Enhances The Dominance Of Grasses Over Forbs In A Temperate Steppe Ecosystem", "description": "<p>Abstract. Chinese grasslands are extensive natural ecosystems that comprise 40 % of the total land area of the country and are sensitive to N deposition. A field experiment with six N rates (0, 30, 60, 120, 240, and 480 kg N ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921) was conducted at Duolun, Inner Mongolia, during 2005 and 2010 to identify some effects of N addition on a temperature steppe ecosystem. The dominant plant species in the plots were divided into two categories, grasses and forbs, on the basis of species life forms. Enhanced N deposition, even as little as 30 kg N ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921 above ambient N deposition (16 kg N ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921), led to a decline in species richness. The cover of grasses increased with N addition rate but their species richness showed a weak change across N treatments. Both species richness and cover of forbs declined strongly with increasing N deposition as shown by linear regression analysis (p&lt;0.05). Increasing N deposition elevated aboveground production of grasses but lowered aboveground biomass of forbs. Plant N concentration, plant \uffce\uffb415N and soil mineral N increased with N addition, showing positive relationships between plant \uffce\uffb415N and N concentration, soil mineral N and/or applied N rate. The cessation of N application in the 480 kg N ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921 treatment in 2009 and 2010 led to a slight recovery of the forb species richness relative to total cover and aboveground biomass, coinciding with reduced plant N concentration and soil mineral N. The results show that N deposition induced changes in soil N transformations and plant N assimilation that are key to changes in species composition and biomass accumulation in this temperate steppe ecosystem.                         </p>", "keywords": ["0106 biological sciences", "2. Zero hunger", "QE1-996.5", "Ecology", "/dk/atira/pure/subjectarea/asjc/1900/1904", "Geology", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences", "6. Clean water", "Life", "13. Climate action", "QH501-531", "0401 agriculture", " forestry", " and fisheries", "14. Life underwater", "/dk/atira/pure/subjectarea/asjc/1100/1105", "Ecology", " Evolution", " Behavior and Systematics", "QH540-549.5", "Earth-Surface Processes"]}, "links": [{"href": "https://doi.org/10.5194/bg-8-2341-2011"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Biogeosciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.5194/bg-8-2341-2011", "name": "item", "description": "10.5194/bg-8-2341-2011", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5194/bg-8-2341-2011"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2011-05-25T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=%2Fdk%2Fatira%2Fpure%2Fsubjectarea%2Fasjc%2F1900%2F1904&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=%2Fdk%2Fatira%2Fpure%2Fsubjectarea%2Fasjc%2F1900%2F1904&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=%2Fdk%2Fatira%2Fpure%2Fsubjectarea%2Fasjc%2F1900%2F1904&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=%2Fdk%2Fatira%2Fpure%2Fsubjectarea%2Fasjc%2F1900%2F1904&offset=4", "hreflang": "en-US"}], "numberMatched": 4, "numberReturned": 4, "distributedFeatures": [], "timeStamp": "2026-06-24T10:28:51.581597Z"}