{"type": "FeatureCollection", "features": [{"id": "10.1016/j.fcr.2017.04.016", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-30T16:16:41Z", "type": "Journal Article", "created": "2017-05-05", "title": "Is Maize-Cowpea Intercropping A Viable Option For Smallholder Farms In The Risky Environments Of Semi-Arid Southern Africa?", "description": "Intercropping cereals with legumes can potentially enhance productivity and soil fertility. There is limited experimental evidence on the mechanisms underlying benefits or risks in intercropping systems and below-ground interactions in intercrops remain largely unstudied. Such understanding can inform strategies towards maximising returns to investments, particularly in poor fertility soils on smallholder farms in semi-arid areas of sub-Saharan Africa. Additive intercropping experiments were established covering several seasons (2010/11\u20132014/15) and different conditions (on-station and on-farm) to determine effects on soil chemical variables, root dynamics and yield of intercrops. Maize was planted with the first effective rains and received either no fertiliser or 40 kg N ha\u22121. Cowpea was planted on the same date as maize or three weeks after planting maize in intercrops or sole stands and received no fertiliser. End-of-season available N was highest (P 1. Intercropping, however, resulted in compromised cowpea yields especially under the relay intercrop compared with the sole cowpea stands whilst maize yield was either not affected or improved. We attributed this to the lack of below-ground niche differentiation in root distribution between maize and cowpea. Maize\u2013cowpea intercropping with low doses of N fertiliser resulted in over-yielding compared with monocropping. Intercropping proved to be a robust option across seasons and soil types, confirming that it is a promising option for resource-poor smallholders.", "keywords": ["Zimbabwe", "Interspecific facilitation", "Root length density", "2. Zero hunger", "570", "Cereals", "04 agricultural and veterinary sciences", "15. Life on land", "630", "Land-use efficiency", "Maize", "Soil", "Niche differentiation", "Intercropping", "Drylands Agriculture", "African Agriculture", "Legume Crops", "0401 agriculture", " forestry", " and fisheries", "Crop Yield", "Root distribution", "Southern Africa", "Below-ground complementarity"]}, "links": [{"href": "https://doi.org/10.1016/j.fcr.2017.04.016"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Field%20Crops%20Research", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.fcr.2017.04.016", "name": "item", "description": "10.1016/j.fcr.2017.04.016", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.fcr.2017.04.016"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-08-01T00:00:00Z"}}, {"id": "10.1038/s41396-019-0465-1", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-30T16:18:17Z", "type": "Journal Article", "created": "2019-06-27", "title": "Plant-driven niche differentiation of ammonia-oxidizing bacteria and archaea in global drylands", "description": "Abstract

Under controlled laboratory conditions, high and low ammonium availability are known to favor soil ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities, respectively. However, whether this niche segregation is maintained under field conditions in terrestrial ecosystems remains unresolved, particularly at the global scale. We hypothesized that perennial vegetation might favor AOB vs. AOA communities compared with adjacent open areas devoid of perennial vegetation (i.e., bare soil) via several mechanisms, including increasing the amount of ammonium in soil. To test this niche-differentiation hypothesis, we conducted a global field survey including 80 drylands from 6 continents. Data supported our hypothesis, as soils collected under plant canopies had higher levels of ammonium, as well as higher richness (number of terminal restriction fragments; T-RFs) and abundance (qPCR amoA genes) of AOB, and lower richness and abundance of AOA, than those collected in open areas located between plant canopies. Some of the reported associations between plant canopies and AOA and AOB communities can be a consequence of the higher organic matter and available N contents found under plant canopies. Other aspects of soils associated with vegetation including shading and microclimatic conditions might also help explain our results. Our findings provide strong evidence for niche differentiation between AOA and AOB communities in drylands worldwide, advancing our understanding of their ecology and biogeography at the global scale.Nitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major cultivated phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest affinity for both ammonia and total ammonium of any characterized AOA, and these values are similar to previously determined ammonia and total ammonium affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values supports the hypothesis that\uffe2\uff80\uff94like for AOB\uffe2\uff80\uff94ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.

Fungi regulate nutrient cycling, decomposition, symbiosis, and pathogenicity in cropland soils. However, the relative importance of generalist and specialist taxa in structuring soil fungal community remains largely unresolved. We hypothesized that generalist fungi, which are adaptable to various environmental conditions, could potentially dominate the community and become the basis for fungal coexisting networks in cropping systems. In this study, we identified the generalist and habitat specialist fungi in cropland soils across a 2,200 kms environmental gradient, including three bioclimatic regions (subtropical, warm temperate, and temperate). A few fungal taxa in our database were classified as generalist taxa (~1%). These generalists accounted for >35% of the relative abundance of all fungal populations, and most of them are Ascomycota and potentially pathotrophic. Compared to the specialist taxa (5\u201317% of all phylotypes in three regions), generalists had a higher degree of connectivity and were often identified as hub within the network. Structural equation modeling provided further evidence that after accounting for spatial and climatic/edaphic factors, generalists had larger contributions to the fungal coexistence pattern than habitat specialists. Taken together, our study provided evidence that generalist taxa are crucial components for fungal community structure. The knowledge of generalists can provide important implication for understanding the ecological preference of fungal groups in cropland systems.

", "keywords": ["0301 basic medicine", "570", "0303 health sciences", "500", "15. Life on land", "Microbiology", "333", "QR1-502", "niche differentiation", "3. Good health", "03 medical and health sciences", "coexistence pattern", "XXXXXX - Unknown", "cropland soil", "soil fungi", "functional traits", "community structure", "ecological network"]}, "links": [{"href": "https://doi.org/10.3389/fmicb.2021.678290"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/fmicb.2021.678290", "name": "item", "description": "10.3389/fmicb.2021.678290", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/fmicb.2021.678290"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-07-09T00:00:00Z"}}, {"id": "10261/336243", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-05-30T16:25:50Z", "type": "Journal Article", "created": "2019-06-27", "title": "Plant-driven niche differentiation of ammonia-oxidizing bacteria and archaea in global drylands", "description": "Abstract

Under controlled laboratory conditions, high and low ammonium availability are known to favor soil ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities, respectively. However, whether this niche segregation is maintained under field conditions in terrestrial ecosystems remains unresolved, particularly at the global scale. We hypothesized that perennial vegetation might favor AOB vs. AOA communities compared with adjacent open areas devoid of perennial vegetation (i.e., bare soil) via several mechanisms, including increasing the amount of ammonium in soil. To test this niche-differentiation hypothesis, we conducted a global field survey including 80 drylands from 6 continents. Data supported our hypothesis, as soils collected under plant canopies had higher levels of ammonium, as well as higher richness (number of terminal restriction fragments; T-RFs) and abundance (qPCR amoA genes) of AOB, and lower richness and abundance of AOA, than those collected in open areas located between plant canopies. Some of the reported associations between plant canopies and AOA and AOB communities can be a consequence of the higher organic matter and available N contents found under plant canopies. Other aspects of soils associated with vegetation including shading and microclimatic conditions might also help explain our results. Our findings provide strong evidence for niche differentiation between AOA and AOB communities in drylands worldwide, advancing our understanding of their ecology and biogeography at the global scale.Under controlled laboratory conditions, high and low ammonium availability are known to favor soil ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities, respectively. However, whether this niche segregation is maintained under field conditions in terrestrial ecosystems remains unresolved, particularly at the global scale. We hypothesized that perennial vegetation might favor AOB vs. AOA communities compared with adjacent open areas devoid of perennial vegetation (i.e., bare soil) via several mechanisms, including increasing the amount of ammonium in soil. To test this niche-differentiation hypothesis, we conducted a global field survey including 80 drylands from 6 continents. Data supported our hypothesis, as soils collected under plant canopies had higher levels of ammonium, as well as higher richness (number of terminal restriction fragments; T-RFs) and abundance (qPCR amoA genes) of AOB, and lower richness and abundance of AOA, than those collected in open areas located between plant canopies. Some of the reported associations between plant canopies and AOA and AOB communities can be a consequence of the higher organic matter and available N contents found under plant canopies. Other aspects of soils associated with vegetation including shading and microclimatic conditions might also help explain our results. Our findings provide strong evidence for niche differentiation between AOA and AOB communities in drylands worldwide, advancing our understanding of their ecology and biogeography at the global scale.Nitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major cultivated phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest affinity for both ammonia and total ammonium of any characterized AOA, and these values are similar to previously determined ammonia and total ammonium affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values supports the hypothesis that\uffe2\uff80\uff94like for AOB\uffe2\uff80\uff94ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.

Fungi regulate nutrient cycling, decomposition, symbiosis, and pathogenicity in cropland soils. However, the relative importance of generalist and specialist taxa in structuring soil fungal community remains largely unresolved. We hypothesized that generalist fungi, which are adaptable to various environmental conditions, could potentially dominate the community and become the basis for fungal coexisting networks in cropping systems. In this study, we identified the generalist and habitat specialist fungi in cropland soils across a 2,200 kms environmental gradient, including three bioclimatic regions (subtropical, warm temperate, and temperate). A few fungal taxa in our database were classified as generalist taxa (~1%). These generalists accounted for >35% of the relative abundance of all fungal populations, and most of them are Ascomycota and potentially pathotrophic. Compared to the specialist taxa (5\u201317% of all phylotypes in three regions), generalists had a higher degree of connectivity and were often identified as hub within the network. Structural equation modeling provided further evidence that after accounting for spatial and climatic/edaphic factors, generalists had larger contributions to the fungal coexistence pattern than habitat specialists. Taken together, our study provided evidence that generalist taxa are crucial components for fungal community structure. The knowledge of generalists can provide important implication for understanding the ecological preference of fungal groups in cropland systems.

", "keywords": ["0301 basic medicine", "570", "0303 health sciences", "500", "15. Life on land", "Microbiology", "333", "QR1-502", "niche differentiation", "3. Good health", "03 medical and health sciences", "coexistence pattern", "XXXXXX - Unknown", "cropland soil", "soil fungi", "functional traits", "community structure", "ecological network"]}, "links": [{"href": "https://doi.org/1959.7/uws:62958"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "1959.7/uws:62958", "name": "item", "description": "1959.7/uws:62958", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/1959.7/uws:62958"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-07-09T00:00:00Z"}}, {"id": "2954010181", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-05-30T16:27:11Z", "type": "Journal Article", "created": "2019-06-27", "title": "Plant-driven niche differentiation of ammonia-oxidizing bacteria and archaea in global drylands", "description": "Abstract

Under controlled laboratory conditions, high and low ammonium availability are known to favor soil ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities, respectively. However, whether this niche segregation is maintained under field conditions in terrestrial ecosystems remains unresolved, particularly at the global scale. We hypothesized that perennial vegetation might favor AOB vs. AOA communities compared with adjacent open areas devoid of perennial vegetation (i.e., bare soil) via several mechanisms, including increasing the amount of ammonium in soil. To test this niche-differentiation hypothesis, we conducted a global field survey including 80 drylands from 6 continents. Data supported our hypothesis, as soils collected under plant canopies had higher levels of ammonium, as well as higher richness (number of terminal restriction fragments; T-RFs) and abundance (qPCR amoA genes) of AOB, and lower richness and abundance of AOA, than those collected in open areas located between plant canopies. Some of the reported associations between plant canopies and AOA and AOB communities can be a consequence of the higher organic matter and available N contents found under plant canopies. Other aspects of soils associated with vegetation including shading and microclimatic conditions might also help explain our results. Our findings provide strong evidence for niche differentiation between AOA and AOB communities in drylands worldwide, advancing our understanding of their ecology and biogeography at the global scale.Nitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major cultivated phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest affinity for both ammonia and total ammonium of any characterized AOA, and these values are similar to previously determined ammonia and total ammonium affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values supports the hypothesis that\uffe2\uff80\uff94like for AOB\uffe2\uff80\uff94ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.