{"type": "FeatureCollection", "features": [{"id": "10.1007/s11104-012-1411-4", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-24T16:15:48Z", "type": "Journal Article", "created": "2012-08-14", "title": "Biochar Application Reduces Nodulation But Increases Nitrogenase Activity In Clover", "description": "Background and aims: Biochar is produced from the pyrolysis of organic materials, and when buried in soil can act as a long term soil carbon (C) store. Evidence suggests that biochar can also increase crop yields, reduce nutrient leaching and increase biological nitrogen fixation in leguminous plants. However, the potential for increasing biological N2 fixation in agroecosystems is poorly understood, with inconsistent reports of root nodulation following biochar application. Therefore, the aim of this study was to determine the effect of biochar application rate and time since application on nodulation and nitrogenase activity in nodules of clover grown in a temperate agricultural soil. Methods: We used replicated field plots with three biochar application rates (0, 25 and 50 t ha-1). Three years after biochar amendment, the plots were further split and fresh biochar added at two different rates (25 and 50 t ha-1) resulting in double-loaded reapplications of 25&thinsp;+&thinsp;25 and 50&thinsp;+&thinsp;50 t ha-1. Results: Three years after biochar application, there was no significant difference in the total number of root nodules between biochar-amended and unamended soil, regardless of the application rate. However, despite clover root nodules being of a similar number and size the level of nitrogenase activity of individual nodules in biochar-amended soil was significantly higher than in unamended soil. Reapplication of biochar resulted in decreased nodulation, although the rate of nitrogenase activity per nodule remained unaffected. Conclusion: In the short term, biochar influences root nodule number and localised N2 fixation per nodule; however, total nitrogenase activity for the whole root system remained unaffected by the application rate of biochar or time since its application. These results emphasise the importance of long-term field studies, with a variety of applications rates for determining the influence of biochar applications on N2-fixing organisms and in providing data that can meaningfully inform agronomic management decisions and climate change mitigation strategies.", "keywords": ["Carbon sequestration", "2. Zero hunger", "Climate change mitigation", "Legume-Rhizobia symbiosis", "13. Climate action", "Black nitrogen", "0401 agriculture", " forestry", " and fisheries", "Biological nitrogen fixation", "04 agricultural and veterinary sciences", "15. Life on land", "630", "Long term biochar trial", "6. Clean water"]}, "links": [{"href": "http://dspace.stir.ac.uk/bitstream/1893/18417/1/Plant%20Soil%202013.pdf"}, {"href": "https://doi.org/10.1007/s11104-012-1411-4"}, {"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": "10.1007/s11104-012-1411-4", "name": "item", "description": "10.1007/s11104-012-1411-4", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-012-1411-4"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-08-15T00:00:00Z"}}, {"id": "10.1016/j.geoderma.2016.08.026", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-24T16:17:06Z", "type": "Journal Article", "created": "2016-09-24", "title": "Black Carbon And Black Nitrogen Storage Under Long-Term Paddy And Non-Paddy Management In Major Reference Soil Groups", "description": "Crop-residue burning and frequent paddy-soil flooding can lead to a substantial accumulation of black carbon (BC), thus contributing to long-term C sequestration. There is evidence that the turnover of BC in soils also depends on the soil mineral assembly. We studied the effects of paddy and non-paddy soil management and different major reference soil groups on BC storage. We hypothesized that overall BC storage in soil relates to paddy management and the abundance of reactive mineral phases such as Fe and Al oxides, and clay-sized minerals. Parallel to BC, black nitrogen (BN) should accumulate in soil.    Paddy and non-paddy soils were sampled in three different climate zones (tropical, subtropical, and temperate). The soil profiles comprised six replicates of Andosols, Alisols and Vertisols from Java (Indonesia), and Alisols and Cambisols from China, as well as one Fluvisol and Gleysol from Northern Italy.    Samples were taken by horizon down to >\u00a01\u00a0m depth and analyzed for soil organic carbon (SOC) and BC. The latter was analyzed by oxidation to benzene polycarboxylic acids. Abundance of BN (as aromatic N) was estimated by X-ray photoelectron spectroscopic analyses of selected topsoil horizons.    In topsoils BC vs. SOC accumulation was affected by management for Andosol, Alisols in China, and Vertisols. However, both flooding and crop-residue management seemed to control this. BC contents relative to SOC also differed between the reference soil groups, independent of management (p\u00a0<\u00a00.0001), yet were surprisingly constant within replicates. We conclude that BC co-accumulated with SOC in all soils. However, the overall storage of BC (1\u00a0m depth) was affected by a combination of soil group and management. Vertisols contained the largest BC stocks (17\u201319\u00a0t\u00a0ha\u2212\u00a01 in non-paddy and paddy fields), followed by Andosols and Alisols (6\u201310\u00a0t\u00a0BC\u00a0ha\u2212\u00a01 under paddy management; 3\u20138\u00a0t\u00a0ha\u2212\u00a01 under non-paddy management). The Gleysol and Fluvisol had the smallest BC stocks, independent of soil use (3\u20134\u00a0t\u00a0ha\u2212\u00a01).    Aromatic N proportions increased to >\u00a050% of total N after combustion of rice straw. However, aromatic N was barely, or not detectable in soil, and there was no correlation to BC. We conclude that burned crop residues were not a major source for aromatic N in soil. BC and aromatic N showed no distinct relations to soil properties, such as the abundance of clay-sized minerals, and Al and Fe oxides. Differences in BC stocks between the soils were most pronounced in the subsoils, likely caused by physical processes, such as swelling and shrinking of clays and/or translocation by leaching. Climate and regional soil-adjusted management also affected BC accumulation, but this first snapshot indicates that global BC maps may be linked to global soil maps.", "keywords": ["2. Zero hunger", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences", "Aluminum oxides; Black carbon; Black nitrogen; C sequestration; Clay-size fraction; Iron oxides; Soil Science", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://iris.unito.it/bitstream/2318/1607391/2/Geoderma_284_214_postprint_4aperto.pdf"}, {"href": "https://doi.org/10.1016/j.geoderma.2016.08.026"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geoderma", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.geoderma.2016.08.026", "name": "item", "description": "10.1016/j.geoderma.2016.08.026", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.geoderma.2016.08.026"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-12-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Black+nitrogen&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=Black+nitrogen&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=Black+nitrogen&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Black+nitrogen&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-06-25T05:20:01.698205Z"}