{"type": "FeatureCollection", "features": [{"id": "10.1007/978-1-4020-5760-1_55", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:14:03Z", "type": "Journal Article", "created": "2006-10-03", "title": "Comparative Short-Term Effects Of Different Quality Organic Resources On Maize Productivity Under Two Different Environments In Zimbabwe", "description": "Major challenges for combined use of organic and mineral nutrient sources in smallholder agriculture include variable type and quality of the resources, their limited availability, timing of their relative application and the proportions at which the two should be combined. Short-term nutrient supply capacity of five different quality organic resources ranging from high to low quality, namely Crotalaria juncea, Calliandra calothyrsus, cattle manure, maize stover and Pinus patula sawdust were tested in the field using maize as a test crop. The study was conducted on two contrasting soil types at Makoholi and Domboshawa, which fall under different agro-ecological regions of Zimbabwe. Makoholi is a semi-arid area ( 750 mm yr\u22121) soils are sandy-clay loams with 220 g kg\u22121 clay. Each organic resource treatment was applied at low (2.5 t C ha\u22121) and high (7.5 t C ha\u22121) biomass rates at each site. Each plot was sub-divided into two with one half receiving 120 kg N ha\u22121 against zero in the other. At Makoholi, there was a nine-fold increase in maize grain yield under high application rates of C. juncea over the unfertilized control, which yielded only 0.4 t ha\u22121. Combinations of mineral N fertilizer with the leguminous resources and manure resulted in between 24% and 104% increase in grain yield against sole fertilizer, implying an increased nutrient recovery by maize under organic\u2013mineral combinations. Maize biomass measured at 2 weeks after crop emergence already showed treatment differences, with biomass yields increasing linearly with soil mineral N availability (R2 = 0.75). This 2-week maize biomass in turn gave a positive linear relationship (R2 = 0.82) with grain yield suggesting that early season soil mineral N availability largely determined final yield. For low quality resources of maize stover and sawdust, application of mineral N fertilizer resulted in at least a seven-fold grain yield increase compared with sole application of the organic resources. Such nutrient combinations resulted in grain harvest indices of between 44% and 48%, up from a mean of 35% for sole application, suggesting the potential of increasing maize productivity from combinations of low quality resources with mineral fertilizer under depleted sandy soils. At Domboshawa, grain yields averaged 7 t ha\u22121 and did not show any significant treatment differences. This was attributed to relatively high levels of fertility under the sandy-clay loams during this first year of the trial implementation. Differences in N supply by different resources were only revealed in grain and stover uptake. Grain N concentration from the high quality leguminous resources averaged 2% against 1.5% from sawdust treatments. We conclude that early season soil mineral N availability is the primary regulatory factor for maize productivity obtainable under poor sandy soils. Maize biomass at 2 weeks is a potential tool for early season assessment of potential yields under constrained environments. However, the likely impact on system productivity following repeated application of high N-containing organic materials on different soil types remains poorly understood.", "keywords": ["0106 biological sciences", "2. Zero hunger", "yields", "fertilizer application", "abonos nitrogenados", "04 agricultural and veterinary sciences", "15. Life on land", "maize", "01 natural sciences", "ma\u00edz", "nitrogen fertilizers", "0401 agriculture", " forestry", " and fisheries", "organic fertilizers", "abonos org\u00e1nicos", "aplicaci\u00f3n de abonos", "rendimiento"]}, "links": [{"href": "https://doi.org/10.1007/978-1-4020-5760-1_55"}, {"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": "10.1007/978-1-4020-5760-1_55", "name": "item", "description": "10.1007/978-1-4020-5760-1_55", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/978-1-4020-5760-1_55"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-10-03T00:00:00Z"}}, {"id": "10.1007/s00374-011-0539-3", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:14:18Z", "type": "Journal Article", "created": "2011-01-18", "title": "Effects Of Organic And Inorganic Fertilization On Soil Bacterial And Fungal Microbial Diversity In The Kabete Long-Term Trial, Kenya", "description": "The effects of crop manure and inorganic fertilizers on composition of microbial communities of central high land soils of Kenya are poorly known. For this reason, we have carried out a thirty-two-year-old long-term trial in Kabete, Kenya. These soils were treated with organic (maize stover (MS) at 10 t ha\u22121, farmyard manure (FYM) at 10 t ha\u22121) and inorganic fertilizers 120 kg N, 52.8 kg P (N2P2), N2P2 + MS, N2P2 + FYM, a control, and a fallow for over 30 years. We examined 16S rRNA gene and 28S rRNA gene fingerprints of bacterial and fungal diversity by PCR amplification and denaturing gradient gel electrophoresis separation, respectively. The PCR bacterial community structure and diversity were negatively affected by N2P2 and were more closely related to the bacterial structure in the soils without any addition (control) than that of soils with a combination of inorganic and organic or inorganic fertilizers alone. The effect on fungal diversity by N2P2 was different than the effect on bacterial diversity since the fungal diversity was similar to that of the N2P2 + FYM and N2P2 + MS-treated. However, soils treated with organic inputs clustered away from soils amended with inorganic inputs. Organic inputs had a positive effect on both bacterial and fungal diversity with or without chemical fertilizers. Results from this study suggested that total diversity of bacterial and fungal communities was closely related to agro-ecosystem management practices and may partially explain the yield differences observed between the different treatments.", "keywords": ["[SDV.SA]Life Sciences [q-bio]/Agricultural sciences", "Microbial diversity", "soil microorganisms", "engrais organique", "http://aims.fao.org/aos/agrovoc/c_27870", "Organic and inorganic amendments", "F08 - Syst\u00e8mes et modes de culture", "rendement des cultures", "630", "fertilisation", "biodiversit\u00e9", "http://aims.fao.org/aos/agrovoc/c_4592", "http://aims.fao.org/aos/agrovoc/c_36669", "http://aims.fao.org/aos/agrovoc/c_2018", "inorganic fertilizers", "http://aims.fao.org/aos/agrovoc/c_10795", "http://aims.fao.org/aos/agrovoc/c_34326", "fertility", "2. Zero hunger", "[SDV.SA] Life Sciences [q-bio]/Agricultural sciences", "http://aims.fao.org/aos/agrovoc/c_33949", "g\u00e9n\u00e9tique des populations", "04 agricultural and veterinary sciences", "agro\u00e9cosyst\u00e8me", "6. Clean water", "fertilit\u00e9 du sol", "PCR", "http://aims.fao.org/aos/agrovoc/c_34079", "polymerization", "community structure", "abonos inorg\u00e1nicos", "management", "570", "http://aims.fao.org/aos/agrovoc/c_7170", "http://aims.fao.org/aos/agrovoc/c_7172", "flore microbienne", "soil", "http://aims.fao.org/aos/agrovoc/c_36167", "micro-organisme du sol", "http://aims.fao.org/aos/agrovoc/c_10176", "organic fertilizers", "abonos org\u00e1nicos", "pratique culturale", "microorganismos del suelo", "suelo", "flore du sol", "P35 - Fertilit\u00e9 du sol", "P34 - Biologie du sol", "polimerizaci\u00f3n", "15. Life on land", "engrais min\u00e9ral", "http://aims.fao.org/aos/agrovoc/c_16367", "http://aims.fao.org/aos/agrovoc/c_4086", "0401 agriculture", " forestry", " and fisheries", "F04 - Fertilisation"]}, "links": [{"href": "https://doi.org/10.1007/s00374-011-0539-3"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Biology%20and%20Fertility%20of%20Soils", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s00374-011-0539-3", "name": "item", "description": "10.1007/s00374-011-0539-3", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s00374-011-0539-3"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2011-01-19T00:00:00Z"}}, {"id": "10.1007/s10457-006-9027-4", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:14:31Z", "type": "Journal Article", "created": "2007-01-17", "title": "Effects Of Organic And Mineral Fertilizer Inputs On Maize Yield And Soil Chemical Properties In A Maize Cropping System In Meru South District, Kenya", "description": "Soil nutrient depletion as a result of continuous cultivation of soils without adequate addition of external inputs is a major challenge in the highlands of Kenya. An experiment was set up in Meru South District, Kenya in 2000 to investigate the effects of different soil-incorporated organic (manure, Tithonia diversifolia, Calliandra calothyrsus, Leucaena leucocephala) and mineral fertilizer inputs on maize yield, and soil chemical properties over seven seasons. On average, tithonia treatments (with or without half recommended rate of mineral fertilizer) gave the highest grain yield (5.5 and 5.4\u00a0Mg\u00a0ha\u22121 respectively) while the control treatment gave the lowest yield (1.5\u00a0Mg\u00a0ha\u22121). After 2\u00a0years of trial implementation, total soil carbon and nitrogen contents were improved with the application of organic residues, and manure in particular improved soil calcium content. Results of the economic analysis indicated that on average across the seven seasons, tithonia with half recommended rate of mineral fertilizer treatment recorded the highest net benefit (USD 787\u00a0ha\u22121) while the control recorded the lowest (USD 272\u00a0ha\u22121). However, returns to labor or benefit-cost ratios were in most cases not significantly improved when organic materials were used.", "keywords": ["2. Zero hunger", "soil fertility", "yields", "forestry", "cropping systems", "04 agricultural and veterinary sciences", "fertilidad del suelo", "15. Life on land", "maize", "6. Clean water", "ma\u00edz", "sistemas de cultivo", "0401 agriculture", " forestry", " and fisheries", "inorganic fertilizers", "organic fertilizers", "abonos org\u00e1nicos", "abonos inorg\u00e1nicos", "rendimiento"]}, "links": [{"href": "https://doi.org/10.1007/s10457-006-9027-4"}, {"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/s10457-006-9027-4", "name": "item", "description": "10.1007/s10457-006-9027-4", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10457-006-9027-4"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2007-01-18T00:00:00Z"}}, {"id": "10.1007/s10705-006-9049-3", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:14:39Z", "type": "Journal Article", "created": "2007-10-15", "title": "Appropriate Technologies To Replenish Soil Fertility In Southern Africa", "description": "In southern Africa, soil nutrient reserves are being depleted because of continued nutrient mining without adequate replenishment. The consequent downward spiral of soil fertility has led to a corresponding decline in crop yields, food insecurity, food aid and environmental degradation. The central issue for improving agricultural productivity in southern Africa is how to build up and maintain soil fertility despite the low incomes of smallholder farmers and the increasing land and labour constraints they face. Under this review five main options namely: inorganic fertilizers, grain legumes, animal manures, integrated nutrient management and agroforestry options appropriate to smallholder farmers are presented. Issues addressed in the use of inorganic fertilizers are reduction in fertilizer costs, timely availability and use efficiency. Legumes can be used to diversify farm system productivity but this requires P and lime application to support better legume growth and biological nitrogen fixation (BNF) as well as development of markets for various legume products. Manure availability and quality are central issues in increasing smallholder farm productivity and increasing its efficiency through proper handling and application methods. Integrated nutrient management of soil fertility by combined application of both inputs will increase use efficiency of inputs and reduce costs and increase profitability; but the challenge is often how to raise adequate amounts of either inorganic or organic inputs. Issues such as quality of inputs, nutrient balancing, labour to collect and transport organic inputs and their management need to be optimized. These are the challenges of adoption as are the scaling up of these options to millions of small-scale farmers.", "keywords": ["0106 biological sciences", "grain legumes", "fertilidad del suelo", "leguminosas de grano", "01 natural sciences", "agroforestry", "12. Responsible consumption", "africa meridional", "inorganic fertilizers", "organic fertilizers", "abonos org\u00e1nicos", "2. Zero hunger", "soil fertility", "1. No poverty", "tecnolog\u00eda apropiada", "04 agricultural and veterinary sciences", "15. Life on land", "feed crops", "6. Clean water", "appropriate technology", "13. Climate action", "manejo del suelo", "0401 agriculture", " forestry", " and fisheries", "soil management", "agroforesteria", "abonos inorg\u00e1nicos"], "contacts": [{"organization": "Mafongoya, P.L., Bationo, B. Andr\u00e9, Kihara, Job Maguta, Waswa, Boaz Shaban,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/s10705-006-9049-3"}, {"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/s10705-006-9049-3", "name": "item", "description": "10.1007/s10705-006-9049-3", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10705-006-9049-3"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-11-18T00:00:00Z"}}, {"id": "10.1023/b:fres.0000019043.33580.a6", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:17:28Z", "type": "Journal Article", "created": "2004-03-10", "title": "Nitrogen Fertilizer Equivalencies Of Organics Of Differing Quality And Optimum Combination With Inorganic Nitrogen Source In Central Kenya", "description": "Decline in crop yields is a major problem facing smallholder farmers in Kenya and the entire Sub-Saharan region. This is attributed mainly to the mining of major nutrients due to continuous cropping without addition of adequate external nutrients. In most cases inorganic fertilizers are expensive, hence unaffordable to most smallholder farmers. Although organic nutrient sources are available, information about their potential use is scanty. A field experiment was set up in the sub-humid highlands of Kenya to establish the chemical fertilizer equivalency values of different organic materials based on their quality. The experiment consisted of maize plots to which freshly collected leaves of Tithonia diversifolia (tithonia), Senna spectabilis (senna) and Calliandra calothyrsus (calliandra) (all with %N>3) obtained from hedgerows grown ex situ (biomass transfer) and urea (inorganic nitrogen source) were applied. Results obtained for the cumulative above ground biomass yield for three seasons indicated that a combination of both organic and inorganic nutrient source gave higher maize biomass yield than when each was applied separately. Above ground biomass yield production in maize (t ha\u22121) from organic and inorganic fertilization was in the order of senna+urea (31.2), tithonia+urea (29.4), calliandra+urea (29.3), tithonia (28.6), senna (27.9), urea (27.4), calliandra (25.9), and control (22.5) for three cumulative seasons. On average, the three organic materials (calliandra, senna and tithonia) gave fertilizer equivalency values for the nitrogen contained in them of 50, 87 and 118%, respectively. It is therefore recommended that tithonia biomass be used in place of mineral fertilizer as a source of nitrogen. The high equivalency values can be attributed to the synergetic effects of nutrient supply, and improved moisture and soil physical conditions of the mulch. However, for sustainable agricultural production, combination with mineral fertilizer would be the best option.", "keywords": ["2. Zero hunger", "Organic", "biomass", "N fertilizer equivalency", "yields", "abonos nitrogenados", "04 agricultural and veterinary sciences", "910", "15. Life on land", "maize", "N-sources", "6. Clean water", "ma\u00edz", "12. Responsible consumption", "Inorganic", "zea mays", "nitrogen fertilizers", "biomasa", "0401 agriculture", " forestry", " and fisheries", "organic fertilizers", "inorganic fertilizers", "abonos org\u00e1nicos", "abonos inorg\u00e1nicos", "rendimiento"]}, "links": [{"href": "https://doi.org/10.1023/b:fres.0000019043.33580.a6"}, {"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": "10.1023/b:fres.0000019043.33580.a6", "name": "item", "description": "10.1023/b:fres.0000019043.33580.a6", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1023/b:fres.0000019043.33580.a6"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-02-01T00:00:00Z"}}, {"id": "10.2134/agronj2008.0188x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:20:03Z", "type": "Journal Article", "created": "2009-09-01", "description": "<p>Organic resources (ORs) are important nutrient inputs in tropical agriculture. Combined with mineral fertilizers, they form the backbone of integrated soil fertility management. This study was conducted to determine the medium\uffe2\uff80\uff90 to long\uffe2\uff80\uff90term influence of OR quality and quantity on maize productivity and to evaluate the occurrence of additive benefits in terms of extra grain yield produced by the combined application of ORs and N fertilizers. Farmyard manure, high quality Mexican sunflower [Tithonia diversifolia (Hemsl.) A. Gray], intermediate quality calliandra (Calliandra calothyrsus Meisn.) and maize (Zea mays L.), and low quality silky\uffe2\uff80\uff90oak (Grevillea robusta A. Cunn. ex R. Br.) sawdust were incorporated into the soil at equivalent rates of 1.2 and 4 Mg C ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921 in Embu (clayey) and Machanga (sandy soil), together with a control to which no OR was added. All plots were split, with one half receiving 120 kg N ha\uffe2\uff88\uff921 season\uffe2\uff88\uff921 as CaNH4NO3. The ORs, except sawdust and maize, improved maize grain yields compared with the control at both sites. Greatest mean maize yields (i.e., 4.9 and 2.3 Mg ha\uffe2\uff88\uff921 season\uffe2\uff88\uff921, in Embu and Machanga, respectively) over 10 seasons were observed with the high rate of Mexican sunflower, but was not significantly different from calliandra and manure. Generally, maize yields were greater with higher than lower OR rates, except for maize and sawdust. Although N fertilizer additions to the ORs improved grain yields in Embu, the increase was marginal; resulting in negative interactive effects of applying ORs with N fertilizers, especially with high\uffe2\uff80\uff90N ORs. Thus high\uffe2\uff80\uff90N ORs should not be applied in combination with N fertilizers, especially at such high fertilizer N rates.</p>", "keywords": ["2. Zero hunger", "soil fertility", "abonos nitrogenados", "04 agricultural and veterinary sciences", "fertilidad del suelo", "15. Life on land", "maize", "630", "ma\u00edz", "soil exhaustion", "nitrogen fertilizers", "cultivos tropicales", "0401 agriculture", " forestry", " and fisheries", "agotamiento del suelo", "estiercol", "farmyard manure", "organic fertilizers", "abonos org\u00e1nicos", "tropical crops"]}, "links": [{"href": "https://doi.org/10.2134/agronj2008.0188x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agronomy%20Journal", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2134/agronj2008.0188x", "name": "item", "description": "10.2134/agronj2008.0188x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2134/agronj2008.0188x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2009-09-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=abonos+org%C3%A1nicos&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=abonos+org%C3%A1nicos&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=abonos+org%C3%A1nicos&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=abonos+org%C3%A1nicos&offset=6", "hreflang": "en-US"}], "numberMatched": 6, "numberReturned": 6, "distributedFeatures": [], "timeStamp": "2026-05-26T03:23:01.088439Z"}