{"type": "FeatureCollection", "features": [{"id": "10.1016/j.agee.2005.10.020", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:15:31Z", "type": "Journal Article", "created": "2006-01-11", "title": "Soil Acidification Without Ph Drop Under Intensive Cropping Systems In Northeast Thailand", "description": "Light textured sandy soils occupy significant areas of Northeast Thailand and are characterized as being acidic to depth with a low inherent fertility. These soils form the basis of agricultural production systems on which significant numbers of people depend upon for livelihoods. The objectives of this study were to investigate soil acidification following the introduction of Stylosanthes in cropping systems of a tropical semi-arid region. Most soils in Northeast Thailand are sandy and acidic (pH 4.0 in CaCl2) with high rate of drainage. Soil acidification was studied over a 6-year period on plots that had been treated either with or without lime additions under different cropping patterns. In the initial first 3 years, a rotation of maize and cowpea was compared to a bare soil treatment where no vegetation was allowed to establish. During the following 3 years, a rotation of maize and Stylosanthes was compared to a continuous Stylosanthes hamata (stylo) treatment. Total soil acidification was calculated from measured pH changes and pH buffer capacity. Acidification due to root system activity was estimated from the above ground biomass production and its ash alkalinity. In the limed systems, soil pH decrease was well correlated with the ash alkalinity of the crop and its removal from the plot. Acidification was highest in the bare soil (6.3 kmol H+ ha(-1) year(-1)), due to leaching of applied N fertilizers. The cowpea-maize rotations did not increase significantly the rate of acid addition (7.6 kmol H+ ha(-1) year(-1)), since the crop residues were returned to the plot. The introduction of stylo in the cropping system resulted in a lower net acidification rate when it was cultivated in rotation with maize (1.3 kmol H+ ha(-1) year(-1)), due to the lower rate of leaching. In contrast, continuous cultivation of stylo triggered accelerated acidification (7.2 kmol H+ ha(-1) year(-1)), as a result of the large quantities of biomass with high ash alkalinity being removed from the plot. In the no-lime system, the pH of the soil profile remained stable at pH 4.0 regardless of the cropping system, even though the acidification rates were quite similar to those in the limed treatments. This would suggest that the soil was strongly buffered at pH 4.0. XRD patterns showed that kaolinite, the main clay mineral, was more disordered and less crystalline in the surface horizons than at depth. It is suggested that the dissolution of kaolinite is responsible for the buffering of soil pH at 4.0. From the dissolution equation of kaolinite, it is expected that the amount of aluminium in the topsoil would increase along with the release silica that would accelerate cementation processes between soil particles resulting in further degradation. (c) 2005 Elsevier B.V. All rights reserved.", "keywords": ["550", "SANDY SOILS", "buffering capacity", "01 natural sciences", "630", "soil degradation", "acidification", "[SDV.EE]Life Sciences [q-bio]/Ecology", "sandy soils", "BUFFERING CAPACITY", "0105 earth and related environmental sciences", "2. Zero hunger", "kaolinite", "SOL SABLEUX", "cropping systems", "04 agricultural and veterinary sciences", "Stylosanthes", "KAOLINITE", "15. Life on land", "6. Clean water", "[SDV.EE] Life Sciences [q-bio]/Ecology", " environment", "ASH ALKALINITY", "0401 agriculture", " forestry", " and fisheries", "environment", "ash alkalinity", "STYLOSANTHES", "ACIDIFICATION"]}, "links": [{"href": "https://doi.org/10.1016/j.agee.2005.10.020"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agriculture%2C%20Ecosystems%20%26amp%3B%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.agee.2005.10.020", "name": "item", "description": "10.1016/j.agee.2005.10.020", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.agee.2005.10.020"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-06-01T00:00:00Z"}}, {"id": "10.1016/j.foreco.2010.09.007", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:16:32Z", "type": "Journal Article", "created": "2010-10-10", "title": "Organic Residue Mass At Planting Is An Excellent Predictor Of Tree Growth In Eucalyptus Plantations Established On A Sandy Tropical Soil", "description": "Abstract   Tropical plantation forests are meeting an increasing proportion of global wood demand and comprehensive studies assessing the impact of silvicultural practices on tree and soil functioning are required to achieve sustainable yields. The objectives of our study were: (1) to quantify the effects of contrasting organic residue (OR) retention methods on tree growth and soil nutrient pools over a full  Eucalyptus  rotation and (2) to assess the potential of soil analyses to predict yields of fast-growing plantations established on tropical sandy soils. An experiment was set up in the Congo at the harvesting of the first rotation after afforestation of a native herbaceous savanna. Six treatments were set up in 0.26\u00a0ha plots and replicated in 4 blocks, with OR mass at planting ranging from 0 to 46.5\u00a0Mg\u00a0ha \u22121 . Tree growth over the whole rotation was highly dependent on OR management at planting. Over-bark trunk volume 7 years after planting ranged from 96\u00a0m 3 \u00a0ha \u22121  in the treatment with forest floor and harvest residue removal at planting to 164\u00a0m 3 \u00a0ha \u22121  in the treatment with the largest amount of OR. A comparison of nutrient stocks within the ecosystem at planting and at the end of the rotation suggested that nutrient contents in OR were largely involved in the different response observed between treatments. OR management treatments did not significantly modify most of the nutrient concentrations in the upper layers of the mineral soil. Conventional soil analyses performed before planting and at ages 1 and 3 years were unable to detect differences between treatments despite large differences in tree growth. In contrast, linear regressions between stand aboveground biomass at harvesting and OR mass at planting (independent variable) showed that OR mass was an excellent predictor of stand yield ( R  2 \u00a0=\u00a00.99). A large share of soil fertility comes from organic material above the mineral soil in highly weathered sandy soils and OR mass at planting might be used in conjunction with soil analyses to assess the potential of these soils to support forest plantations.", "keywords": ["0106 biological sciences", "570", "http://aims.fao.org/aos/agrovoc/c_7170", "[SDV]Life Sciences [q-bio]", "rendement des cultures", "Slash", "F62 - Physiologie v\u00e9g\u00e9tale - Croissance et d\u00e9veloppement", "for\u00eat tropicale", "01 natural sciences", "630", "http://aims.fao.org/aos/agrovoc/c_10176", "http://aims.fao.org/aos/agrovoc/c_24904", "sol tropical", "http://aims.fao.org/aos/agrovoc/c_16118", "http://aims.fao.org/aos/agrovoc/c_5387", "2. Zero hunger", "Eucalyptus", "substance nutritive", "r\u00e9sidu de r\u00e9colte", "P35 - Fertilit\u00e9 du sol", "http://aims.fao.org/aos/agrovoc/c_1811", "15. Life on land", "croissance", "Carbon", "sol sableux", "K10 - Production foresti\u00e8re", "[SDV] Life Sciences [q-bio]", "fertilit\u00e9 du sol", "Residue", "Fertility", "http://aims.fao.org/aos/agrovoc/c_3394", "Indicator", "http://aims.fao.org/aos/agrovoc/c_7978", "mati\u00e8re organique", "Organic matter", "plantations", "http://aims.fao.org/aos/agrovoc/c_5274", "http://aims.fao.org/aos/agrovoc/c_6781", "http://aims.fao.org/aos/agrovoc/c_5990", "Nutrient", "http://aims.fao.org/aos/agrovoc/c_2683"]}, "links": [{"href": "https://doi.org/10.1016/j.foreco.2010.09.007"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Forest%20Ecology%20and%20Management", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.foreco.2010.09.007", "name": "item", "description": "10.1016/j.foreco.2010.09.007", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.foreco.2010.09.007"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-12-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SOL+SABLEUX&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=SOL+SABLEUX&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=SOL+SABLEUX&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SOL+SABLEUX&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-04-15T10:41:19.592933Z"}