{"type": "FeatureCollection", "features": [{"id": "10.1007/s11104-010-0462-7", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-26T16:14:48Z", "type": "Journal Article", "created": "2010-06-16", "title": "Agronomic Use Efficiency Of N Fertilizer In Maize-Based Systems In Sub-Saharan Africa Within The Context Of Integrated Soil Fertility Management", "description": "Traditionally, crop production in sub-Saharan Africa (SSA) depends primarily on mining soil nutrients. Integrated Soil Fertility Management (ISFM) is an approach for intensifying agriculture in SSA that aims at maximizing the agronomic efficiency (AE) of applied nutrient inputs. ISFM contains the following essential components: proper fertilizer management, use of improved varieties, the combined application of organic inputs and fertilizer, and adaptation of input application rates to within-farm soil fertility gradients where these are important. This paper evaluates, through meta-analysis, the impact of these components on the AE of fertilizer N (N-AE), defined as extra grain yield per kg fertilizer N applied, in maize-based systems in SSA. Since N-AE is low for excessive fertilizer N application rates or when fertilizer is applied on fertile, unresponsive soil, as was confirmed by scatter plots against control yields and fertilizer N application rates, such values were removed from the database in order to focus on and elucidate the more variable and complex responses under less than ideal conditions typical for SSA. Compared with local varieties, the use of hybrid maize varieties significantly increased N-AE values (17 and 26\u00a0kg (kg\u00a0N)\u22121, respectively) with no differences observed between local and improved, open-pollinated varieties. Mixing fertilizer with manure or compost resulted in the highest N-AE values [36\u00a0kg (kg\u00a0N)\u22121] while organic inputs of medium quality also showed significantly higher N-AE values compared with the sole fertilizer treatment but only at low organic input application rates (40 and 23\u00a0kg (kg\u00a0N)\u22121, respectively). High quality organic inputs (Class I) and those with a high C-to-N ratio (Class III) or high lignin content (Class IV) did not affect N-AE values in comparison with the sole fertilizer treatment. Application of N fertilizer on infields resulted in significantly higher N-AE values [31\u00a0kg (kg\u00a0N)\u22121] compared with the outfields [17\u00a0kg (kg\u00a0N)\u22121]. The obtained information indicates that N-AE is amenable to improved management practices and that the various components embedded in the ISFM definition result in improvements in N-AE.", "keywords": ["germoplasma", "2. Zero hunger", "nitrogen fertilizers", "soil fertility", "0401 agriculture", " forestry", " and fisheries", "abonos nitrogenados", "04 agricultural and veterinary sciences", "germplasm", "fertilidad del suelo", "15. Life on land", "maize", "africa al sur del sahara", "ma\u00edz"]}, "links": [{"href": "https://doi.org/10.1007/s11104-010-0462-7"}, {"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/s11104-010-0462-7", "name": "item", "description": "10.1007/s11104-010-0462-7", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-010-0462-7"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-06-17T00:00:00Z"}}, {"id": "10.1016/j.agee.2012.10.003", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-26T16:15:12Z", "type": "Journal Article", "created": "2012-11-22", "title": "Medium-Term Impact Of Tillage And Residue Management On Soil Aggregate Stability, Soil Carbon And Crop Productivity", "description": "Conservation agriculture is widely promoted for soil conservation and crop productivity increase, although rigorous empirical evidence from sub-Saharan Africa is still limited. This study aimed to quantify the medium-term impact of tillage (conventional and reduced) and crop residue management (retention and removal) on soil and crop performance in a maize\u2013soybean rotation. A replicated field trial was started in sub-humid Western Kenya in 2003, and measurements were taken from 2005 to 2008. Conventional tillage negatively affected soil aggregate stability when compared to reduced tillage, as indicated by lower mean weight diameter values upon wet sieving at 0\u201315 cm (PT < 0.001). This suggests increased susceptibility to slaking and soil erosion. Tillage and residue management alone did not affect soil C contents after 11 cropping seasons, but when residue was incorporated by tillage, soil C was higher at 15\u201330 cm (PT*R = 0.037). Lack of treatment effects on the C content of different aggregate fractions indicated that reduced tillage and/or residue retention did not increase physical C protection. The weak residue effect on aggregate stability and soil C may be attributed to insufficient residue retention. Soybean grain yields tended to be suppressed under reduced tillage without residue retention, especially in wet seasons (PT*R = 0.070). Consequently, future research should establish, for different climatic zones and soil types, the critical minimum residue retention levels for soil conservation and crop productivity.", "keywords": ["organic-matter dynamics", "crop residues", "agregados del suelo", "no-till", "yields", "nitrogen", "conservaci\u00f3n del suelo", "crop rotation", "2. Zero hunger", "rotaci\u00f3n de cultivos", "carbon", "soil conservation", "04 agricultural and veterinary sciences", "15. 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