{"type": "FeatureCollection", "features": [{"id": "10.1007/s10457-016-9914-2", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:14:59Z", "type": "Journal Article", "created": "2016-02-27", "title": "Effects Of Acacia Seyal And Biochar On Soil Properties And Sorghum Yield In Agroforestry Systems In South Sudan", "description": "We studied the effects of Acacia seyal Del. intercropping and biochar soil amendment on soil physico-chemical properties and sorghum (Sorghum bicolor L.) yields in a two-year field experiment conducted on a silt loam site near Renk in South Sudan. A split-plot design with three replications was used. The main factor was tree-cropping system (dense acacia\u00a0+\u00a0sorghum, scattered acacia\u00a0+\u00a0sorghum, and sole sorghum) and biochar (0 and 10\u00a0Mg\u00a0ha\u22121) was the subplot factor. The two acacia systems had lower soil pH, N and higher C/N ratios compared to the sole sorghum system. Biochar significantly increased soil C, exchangeable K+ contents, field capacity and available water content, but reduced soil exchangeable Ca2+ and effective CEC, and had no effect on soil pH. Acacia intercropping significantly reduced sorghum grain yields while biochar had no significant effect on sorghum yields. The land equivalent ratio (LER) for sorghum yield was 0.3 for both acacia systems in 2011, with or without biochar, but increased in 2012 to 0.6 for the scattered acacia system when combined with biochar. The reduction in sorghum yields by the A. seyal trees was probably due to a combination of competition for water and nutrients and shading. The lack of a yield response to biochar maybe due to insufficient time or too low a dosage. Further research is needed to test for the effects of tree intercropping and biochar and their interactions on soil properties and crop yields in drylands.", "keywords": ["BOREAL LOAMY SAND", "2. Zero hunger", "AGRONOMIC PERFORMANCE", "Land equivalent ratio (LER)", "Forestry", "04 agricultural and veterinary sciences", "15. Life on land", "Agronomy", "NORTH KORDOFAN STATE", "Biochar", "BLUE-NILE REGION", "ORGANIC-MATTER", "CROP YIELDS", "BIOLOGICAL NITROGEN-FIXATION", "Savanna", "Acacia seyal", "TREES", "0401 agriculture", " forestry", " and fisheries", "NERE PARKIA-BIGLOBOSA", "Tree intercropping", "BURKINA-FASO"]}, "links": [{"href": "https://doi.org/10.1007/s10457-016-9914-2"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agroforestry%20Systems", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s10457-016-9914-2", "name": "item", "description": "10.1007/s10457-016-9914-2", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10457-016-9914-2"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-02-27T00:00:00Z"}}, {"id": "10.1007/s10705-008-9174-2", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:15:06Z", "type": "Journal Article", "created": "2008-03-21", "title": "A Comparison Between Legume Technologies And Fallow, And Their Effects On Maize And Soil Traits, In Two Distinct Environments Of The West African Savannah", "description": "Legume\u2013maize rotation and maize nitrogen (N)-response trials were carried out simultaneously from 1998 to 2004 in two distinct agro-ecological environments of West Africa: the humid derived savannah (Ibadan) and the drier northern Guinea savannah (Zaria). In the N-response trial, maize was grown annually receiving urea N at 0, 30, 60, 90 and 120 kg N ha\u22121. In Ibadan, maize production increased with N fertilization, but mean annual grain yield declined over the course of the trial. In Zaria, no response to N treatments was observed initially, and an increase in the phosphorus (P) and sulphur (S) fertilizer application rate was required to increase yield across treatments and obtain a response to N applications, stressing the importance of non-N fertilizers in the savannah. In the rotation trial, a 2-year natural fallow\u2013maize rotation was compared with maize rotated with different legume types: green manure, forage, dual-purpose, and grain legumes. The cultivation of some legume types resulted in a greater annual maize production relative to the fallow\u2013maize combination and corresponding treatments in the N-response trial, while there was no gain in maize yield with other legume types. Large differences in the residual effects from legumes and fallow were also observed between sites, indicting a need for site-specific land management recommendations. In Ibadan, cultivation of maize after the forage legume (Stylosanthes guianensis) achieved the highest yield. The natural fallow\u2013maize rotation had improved soil characteristics (Bray-I P, exchangeable potassium, calcium and magnesium) at the end of the trial relative to legume\u2013maize rotations, and natural fallow resulted in higher maize yields than the green manure legume (Pueraria phaseoloides). In Zaria, maize following dual-purpose soybean achieved the highest mean yield. At both sites, variation in aboveground N and P dynamics of the legume and fallow vegetation could only partly explain the different residual effects on maize.", "keywords": ["2. Zero hunger", "forage legumes", "agropastoral systems", "northern guinea savanna", "livestock systems", "Soil Science", "biological nitrogen-fixation", "increased crop production", "continuous cultivation", "04 agricultural and veterinary sciences", "15. Life on land", "0401 agriculture", " forestry", " and fisheries", "farming systems", "fertility management", "organic-matter", "Agronomy and Crop Science"], "contacts": [{"organization": "Franke, A.C., Laberge, G., Oyewole, B.D., Schulz, S., Tobe, O.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/s10705-008-9174-2"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Nutrient%20Cycling%20in%20Agroecosystems", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s10705-008-9174-2", "name": "item", "description": "10.1007/s10705-008-9174-2", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10705-008-9174-2"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2008-03-22T00:00:00Z"}}, {"id": "10.1073/pnas.0509038103", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:18:09Z", "type": "Journal Article", "created": "2006-04-14", "title": "Element interactions limit soil carbon storage", "description": "<p>             Rising levels of atmospheric CO             2             are thought to increase C sinks in terrestrial ecosystems. The potential of these sinks to mitigate CO             2             emissions, however, may be constrained by nutrients. By using metaanalysis, we found that elevated CO             2             only causes accumulation of soil C when N is added at rates well above typical atmospheric N inputs. Similarly, elevated CO             2             only enhances N             2             fixation, the major natural process providing soil N input, when other nutrients (e.g., phosphorus, molybdenum, and potassium) are added. Hence, soil C sequestration under elevated CO             2             is constrained both directly by N availability and indirectly by nutrients needed to support N             2             fixation.           </p>", "keywords": ["Greenhouse Effect", "Nitrogen", "cycles", "fine roots", "Plant Development", "01 natural sciences", "forest", "Soil", "Nitrogen Fixation", "elevated atmospheric co2", "Ecosystem", "0105 earth and related environmental sciences", "model", "biological nitrogen-fixation", "04 agricultural and veterinary sciences", "Carbon Dioxide", "Plants", "15. Life on land", "Carbon", "6. Clean water", "13. Climate action", "climate-change", "0401 agriculture", " forestry", " and fisheries", "grassland", "ecosystem responses", "metaanalysis"]}, "links": [{"href": "https://doi.org/10.1073/pnas.0509038103"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Proceedings%20of%20the%20National%20Academy%20of%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1073/pnas.0509038103", "name": "item", "description": "10.1073/pnas.0509038103", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1073/pnas.0509038103"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-04-25T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=biological+nitrogen-fixation&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=biological+nitrogen-fixation&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=biological+nitrogen-fixation&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=biological+nitrogen-fixation&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-07-26T06:58:32.614840Z"}