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E. J. P. Marshall - One of the best experts on this subject based on the ideXlab platform.
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impacts of an agri environment Field Margin prescription on the flora and fauna of arable farmland in different landscapes
Agriculture Ecosystems & Environment, 2006Co-Authors: E. J. P. Marshall, T M West, David KleijnAbstract:The hypothesis that sown 6 m grass Margins strips at the edges of arable Fields have a positive impact on farmland biodiversity was tested using a paired Field approach in southern England. A total of 42 Fields were investigated, half with at least 3-year-old Margin strips created under the UK agri-environment scheme Countryside Stewardship and half nearby control sites. The sites were grouped on the basis of average Field size into small, intermediate or open landscape locations to examine landscape structure effects. Assessments of the flora, bird and territory numbers, bees, spiders, Orthoptera and Carabidae were made in early to mid-summer 2003. There were positive impacts on diversity or abundance for the flora, bees and Orthoptera. The herbaceous flora of the pre-existing boundary adjacent to sown 6 m strips was significantly more species-rich than controls, probably reflecting a buffer effect of the strip. Bees and Orthoptera, the latter of which were only found in Field boundaries, were more abundant where strips were sited, reflecting added habitat resources. Bee numbers were significantly lower in Field centres where there were no 6 m Margin strips. There were no significant effects of sown strips on numbers of birds observed or bird territories, spiders or Carabidae, but also no negative impacts. Lycosid spiders were consistently more abundant in boundaries of small Fields with 6 m Margin strips. Linyphiidae were more abundant within the crop area of smaller Fields. Amongst birds, wrens (Troglodytes troglodytes) were also more abundant in small Fields, while yellowhammers (Emberiza citrinella) were more abundant in open landscapes. The results confirm there are benefits to farmland biodiversity from introducing new Margin strips at the edges of arable Fields. More significantly, the success of agri-environment schemes, which will vary between taxa and species, can be dependent on landscape structure. Scheme administrators may need to address landscape structure and mean Field size to achieve significant enhancement of populations of declining farmland species.
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Agricultural Landscapes: Field Margin Habitats and Their Interaction with Crop Production
Journal of Crop Improvement, 2004Co-Authors: E. J. P. MarshallAbstract:SUMMARY Most agricultural landscapes are a mosaic of farmers' Fields, semi-natural habitats, human infrastructures (e.g., roads) and occasional natural habitats. Within such landscapes, linear semi-natural habitats often define the edges of agricultural Fields. This paper reviews the role and interactions within and between the flora and fauna of these elements. In temperate, intensive agriculture, such Field Margin habitats, which historically had true agricultural functions, now are important refugia for biodiversity. As man-made habitats, Field Margins may also have important cultural roles as part of landscape heritage, e.g., hedges in Britain. Although Field Margins are not usually specific or characteristic habitat types, they contain a variety of plant communities in a variety of structures. These may range from aquatic elements, to ruderal and woodland communities, with combinations of them over small spatial scales. Studies demonstrate a variety of interactions between Fields and their Margins. S...
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Introducing Field Margin ecology in Europe
Agriculture Ecosystems & Environment, 2002Co-Authors: E. J. P. MarshallAbstract:In most intensively-managed European farming systems, the uncultivated elements present are linear features in the landscape, typically Field Margins, verges and watercourses. These elements are important for biological diversity in farming landscapes, but also are viewed as sources of weeds, pests and diseases. An understanding of the origins, functions and ecology of these semi-natural elements is required, if these man-made structures are to survive. Increasingly, their agricultural functions are declining in importance, while cultural and environmental roles are increasing. Significant research effort is in progress to understand the ecology of Field Margins at a range of spatial scales. This issue presents a number of papers addressing different aspects of the studies in hand in Europe.
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the influence of sown Margin strips management and boundary structure on herbaceous Field Margin vegetation in two neighbouring farms in southern england
Agriculture Ecosystems & Environment, 2001Co-Authors: A C Moonen, E. J. P. MarshallAbstract:Field Margins are refugia for many species in arable landscapes, but are also affected by adjacent farming operations and by Margin management. Botanical diversity in 117 hedge-bottoms on two neighbouring farms in Yatesbury, Wiltshire, UK, were studied in relation to boundary structure, hedge management practices and adjacent features on the farm to which they belong. The farms differed with regard to Field Margin and hedge management practices, but soil type and cropping patterns were very similar. Attention was also paid to effects of sown grass strips, coppicing and gapping-up of hedges and different approaches towards Field Margin management. Results indicated that there were no significant differences in woody species richness between the two farms, with hedges of similar composition. There was significantly higher herbaceous species diversity on the farm with grass strips. Multivariate analyses indicated that community differences were present, with a number of annual and biennial plant species predominating on the farm without grass Margins. Principal components analysis (PCA), redundancy analysis (RDA) with forward selection and associated Monte-Carlo permutation tests, and stepwise linear regression showed the following. (1) Sown grass and/or wildflower strips adjacent to the hedge-bottom have a positive effect on species richness of the hedge-bottom vegetation. They also reduce the abundance in the hedge-bottom of Anisantha sterilis, Galium aparine, Poa trivialis and Urtica dioica, all four considered to be pernicious weed species. (2) Coppicing in combination with gapping-up of hedges increases species richness of the hedge-bottom vegetation and has a positive effect on floral diversity in the landscape. (3) Diversity in management, boundary structure and adjacent features within one farm increases the floral diversity at the farm scale. Diversity in management, boundary structure and adjacent features between farms increases the floral diversity on a landscape scale.
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Factors affecting Field weed and Field Margin flora on a farm in Essex, UK
Landscape and Urban Planning, 1995Co-Authors: E. J. P. Marshall, G M ArnoldAbstract:Abstract Field Margins, particularly hedgerows, are important refuges for many species in intensively managed arable landscapes. Their management is influenced by the perception that weed species colonise adjacent crops. Mobile species, such as beetles, are able to use Field Margins as corridors to recolonise suitable habitat. This study examines whether Field Margins influence adjacent weed flora, and if there is evidence of the corridor effect of adjacent woodland in Margin plant communities. The higher plants present in 51 Field Margin sites on a large farm in Essex, UK, were recorded. The weed flora in the adjacent arable crops was also assessed in 41 of the sites at 5 and 50 m into the Field. Field Margin floras were much more diverse than the weed flora, though 25% of species in the Margins were also found in the adjacent crops. Most species of the Margin were perennials, while arable weeds were dominated by annual species. There was little correlation between Field Margin and crop flora. The Margin flora was correlated with Margin structure, which ranged from woodland edge, to shelterbelt, to tall and short hedgerows. Principal component analysis of species indicated woodland sites and those close to woodland were differentiated from hedgerows. Site scores were positively correlated with distance from woodland, possibly indicating site history or colonisation along hedges were important in determining plant communities of Field Margins.
David W. Macdonald - One of the best experts on this subject based on the ideXlab platform.
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How can Field Margin management contribute to invertebrate biodiversity
2015Co-Authors: Ruth E. Feber, Paul J. Johnson, W Manley, F Tattersall, Helen Lawton Smith, David W. MacdonaldAbstract:Farmland invertebrates are vital for healthy ecosystem functioning. Many groups have declined due to agricultural intensification. Arable Field Margins potentially can increase food resources and provide winter refuges for invertebrates. They might also buffer them from agrochemical applications and farm operations. This chapter describes a series of Field and farm-scale experiments which show that ways in which arable Field Margins are established and managed can have profound effects on their invertebrate assemblages. Field Margin swards established by sowing with a grass and wildflower seed mixture attracted more butterflies than naturally regenerated swards. In the short term, larger and more species-rich invertebrate assemblages were fostered on unmanaged Margins than on those managed by cutting. The timing of cutting was critical, with mid-summer cutting having the most persistent, negative effects on invertebrates, while cutting in spring and autumn was generally less damaging and may help maintain sward species richness. Fallowed land (set-aside) configured as blocks rather than Margins constituted qualitatively different habitats for invertebrates. Margin width had complex effects on invertebrate abundance and species richness. Boundary hedgerows increased numbers of most invertebrate groups in the adjacent Margin. The chapter suggests that blanket management approaches for invertebrates at the farm scale are not optimal. A diverse farmed landscape, with Margins of different sizes and different sward structures, will provide for the different ecological requirements of invertebrate populations, and promote their diversity in the characteristically unstable environment of arable systems.
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Manipulating the abundance of Lepthyphantes tenuis (Araneae: Linyphiidae) by Field Margin management
Agriculture Ecosystems & Environment, 2002Co-Authors: James R Bell, Ruth E. Feber, Paul J. Johnson, Helen Lawton Smith, Clive Hambler, Alison J Haughton, Fran H Tattersall, Barbara H Hart, Will Manley, David W. MacdonaldAbstract:Populations of the linyphiid spider Lepthyphantes tenuis were sampled in Field Margins in May, July and September in 1990–1991 and 1995–1996. Field Margins were subjected to 10 grassland management regimes, which included the effects of spraying the herbicide glyphosate, cutting, leaving vegetation in situ after the cut, sowing and a control. These treatments were randomised within six complete blocks at the University of Oxford’s farm at Wytham. Cutting vegetation had an immediate effect on number of L. tenuis in both spring and summer. Cutting Margins in summer had a more persistent effect on populations of L. tenuis than did cutting Margins in spring. The effect of cutting was not mitigated by leaving cut vegetation in situ, but no cutting ensured higher number of L. tenuis in Margins, an indication that height and structural complexity of grassland vegetation were important in determining population size. Significantly fewer spiders were found in July and September plots which had been sprayed with herbicide in late June/early July. However, spider numbers were not affected by glyphosate application when samples were taken nearly a year later. Sowing a wildflower seed mixture had no significant effects on number of this generalist predator although other invertebrate groups did benefit. Field Margins provided an excellent source habitat for L. tenuis. Habitats that border crop Fields acted as a refugia for many other beneficial invertebrates and should be retained as an important component of the agricultural landscape.
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Manipulating the abundance of Lepthyphantes tenuis (Araneae: Linyphiidae) by Field Margin management
Agriculture Ecosystems & Environment, 2002Co-Authors: James R Bell, Ruth E. Feber, Paul J. Johnson, Clive Hambler, Alison J Haughton, Helen Smith, Fran H Tattersall, Barbara H Hart, Will Manley, David W. MacdonaldAbstract:Populations of the linyphiid spider Lepthyphantes tenuis were sampled in Field Margins in May, July and September in 1990-1991 and 1995-1996. Field Margins were subjected to 10 grassland management regimes, which included the effects of spraying the herbicide glyphosate, cutting, leaving vegetation in situ after the cut, sowing and a control. These treatments were randomised within six complete blocks at the University of Oxford's farm at Wytham. Cutting vegetation had an immediate effect on number of L. tenuis in both spring and summer. Cutting Margins in summer had a more persistent effect on populations of L. tenuis than did cutting Margins in spring. The effect of cutting was not mitigated by leaving cut vegetation in situ, but no cutting ensured higher number of L. tenuis in Margins, an indication that height and structural complexity of grassland vegetation were important in determining population size. Significantly fewer spiders were found in July and September plots which had been sprayed with herbicide in late June/early July. However, spider numbers were not affected by glyphosate application when samples were taken nearly a year later. Sowing a wildflower seed mixture had no significant effects on number of this generalist predator although other invertebrate groups did benefit. Field Margins provided an excellent source habitat for L. tenuis. Habitats that border crop Fields acted as a refugia for many other beneficial invertebrates and should be retained as an important component of the agricultural landscape. © 2002 Elsevier Science B.V. All rights reserved
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The effects of arable Field Margin management on the abundance and species richness of Araneae (spiders)
Ecography, 1998Co-Authors: M. Baines, Paul J. Johnson, David W. Macdonald, Clive Hambler, Helen Lawton SmithAbstract:The effects of ten different management regimes on the abundance and species richness of Araneae on pre-existing and newly expanded zones of Field Margins surrounding arable Fields are compared in a large-scale experiment conducted between 1987 and 1991. Most of the management regimes involved varying the timing and frequency with which the Field Margins were cut. There was no evidence of consistent temporal trends in the abundance and species richness of Araneae on either the existing or expanded zones of the Field Margins during the first four years of the experiment. However, lowest numbers were recorded before expansion of the Margins in 1987, and highest numbers in the final sample, in 1991. Araneae remained less abundant, and less species rich, on the newly expanded than on the existing zones of the Field Margins four years after they were ' set-aside'. Cutting reduced both abundance and species richness. Regimes which included cutting in mid-summer had a greater impact which persisted for longer than did those involving cutting in spring and autumn. Removal of cut material was associated with lower species richness than leaving it in situ. Sowing the Margins with a wild flower seed mixture was associated with increased abundance and species richness of Araneae. Annual spraying with a broad-spectrum, non-persistent herbicide reduced the abundance of Araneae but the effect was not detectable until several months after the application of the spray. Both the species richness and abundance of Araneae were positively correlated with a measure of vegetation height made on the Field Margins in September, on both the pre-existing and newly expanded zones of the Margins. The extent to which management practices which benefit Araneae are compatible with both the management requirements for various other taxa, and the overriding constraint of effective pernicious weed control on Field Margins, is discussed.
Clive Hambler - One of the best experts on this subject based on the ideXlab platform.
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Manipulating the abundance of Lepthyphantes tenuis (Araneae: Linyphiidae) by Field Margin management
Agriculture Ecosystems & Environment, 2002Co-Authors: James R Bell, Ruth E. Feber, Paul J. Johnson, Helen Lawton Smith, Clive Hambler, Alison J Haughton, Fran H Tattersall, Barbara H Hart, Will Manley, David W. MacdonaldAbstract:Populations of the linyphiid spider Lepthyphantes tenuis were sampled in Field Margins in May, July and September in 1990–1991 and 1995–1996. Field Margins were subjected to 10 grassland management regimes, which included the effects of spraying the herbicide glyphosate, cutting, leaving vegetation in situ after the cut, sowing and a control. These treatments were randomised within six complete blocks at the University of Oxford’s farm at Wytham. Cutting vegetation had an immediate effect on number of L. tenuis in both spring and summer. Cutting Margins in summer had a more persistent effect on populations of L. tenuis than did cutting Margins in spring. The effect of cutting was not mitigated by leaving cut vegetation in situ, but no cutting ensured higher number of L. tenuis in Margins, an indication that height and structural complexity of grassland vegetation were important in determining population size. Significantly fewer spiders were found in July and September plots which had been sprayed with herbicide in late June/early July. However, spider numbers were not affected by glyphosate application when samples were taken nearly a year later. Sowing a wildflower seed mixture had no significant effects on number of this generalist predator although other invertebrate groups did benefit. Field Margins provided an excellent source habitat for L. tenuis. Habitats that border crop Fields acted as a refugia for many other beneficial invertebrates and should be retained as an important component of the agricultural landscape.
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Manipulating the abundance of Lepthyphantes tenuis (Araneae: Linyphiidae) by Field Margin management
Agriculture Ecosystems & Environment, 2002Co-Authors: James R Bell, Ruth E. Feber, Paul J. Johnson, Clive Hambler, Alison J Haughton, Helen Smith, Fran H Tattersall, Barbara H Hart, Will Manley, David W. MacdonaldAbstract:Populations of the linyphiid spider Lepthyphantes tenuis were sampled in Field Margins in May, July and September in 1990-1991 and 1995-1996. Field Margins were subjected to 10 grassland management regimes, which included the effects of spraying the herbicide glyphosate, cutting, leaving vegetation in situ after the cut, sowing and a control. These treatments were randomised within six complete blocks at the University of Oxford's farm at Wytham. Cutting vegetation had an immediate effect on number of L. tenuis in both spring and summer. Cutting Margins in summer had a more persistent effect on populations of L. tenuis than did cutting Margins in spring. The effect of cutting was not mitigated by leaving cut vegetation in situ, but no cutting ensured higher number of L. tenuis in Margins, an indication that height and structural complexity of grassland vegetation were important in determining population size. Significantly fewer spiders were found in July and September plots which had been sprayed with herbicide in late June/early July. However, spider numbers were not affected by glyphosate application when samples were taken nearly a year later. Sowing a wildflower seed mixture had no significant effects on number of this generalist predator although other invertebrate groups did benefit. Field Margins provided an excellent source habitat for L. tenuis. Habitats that border crop Fields acted as a refugia for many other beneficial invertebrates and should be retained as an important component of the agricultural landscape. © 2002 Elsevier Science B.V. All rights reserved
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The effects of arable Field Margin management on the abundance and species richness of Araneae (spiders)
Ecography, 1998Co-Authors: M. Baines, Paul J. Johnson, David W. Macdonald, Clive Hambler, Helen Lawton SmithAbstract:The effects of ten different management regimes on the abundance and species richness of Araneae on pre-existing and newly expanded zones of Field Margins surrounding arable Fields are compared in a large-scale experiment conducted between 1987 and 1991. Most of the management regimes involved varying the timing and frequency with which the Field Margins were cut. There was no evidence of consistent temporal trends in the abundance and species richness of Araneae on either the existing or expanded zones of the Field Margins during the first four years of the experiment. However, lowest numbers were recorded before expansion of the Margins in 1987, and highest numbers in the final sample, in 1991. Araneae remained less abundant, and less species rich, on the newly expanded than on the existing zones of the Field Margins four years after they were ' set-aside'. Cutting reduced both abundance and species richness. Regimes which included cutting in mid-summer had a greater impact which persisted for longer than did those involving cutting in spring and autumn. Removal of cut material was associated with lower species richness than leaving it in situ. Sowing the Margins with a wild flower seed mixture was associated with increased abundance and species richness of Araneae. Annual spraying with a broad-spectrum, non-persistent herbicide reduced the abundance of Araneae but the effect was not detectable until several months after the application of the spray. Both the species richness and abundance of Araneae were positively correlated with a measure of vegetation height made on the Field Margins in September, on both the pre-existing and newly expanded zones of the Margins. The extent to which management practices which benefit Araneae are compatible with both the management requirements for various other taxa, and the overriding constraint of effective pernicious weed control on Field Margins, is discussed.
Helen Lawton Smith - One of the best experts on this subject based on the ideXlab platform.
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How can Field Margin management contribute to invertebrate biodiversity
2015Co-Authors: Ruth E. Feber, Paul J. Johnson, W Manley, F Tattersall, Helen Lawton Smith, David W. MacdonaldAbstract:Farmland invertebrates are vital for healthy ecosystem functioning. Many groups have declined due to agricultural intensification. Arable Field Margins potentially can increase food resources and provide winter refuges for invertebrates. They might also buffer them from agrochemical applications and farm operations. This chapter describes a series of Field and farm-scale experiments which show that ways in which arable Field Margins are established and managed can have profound effects on their invertebrate assemblages. Field Margin swards established by sowing with a grass and wildflower seed mixture attracted more butterflies than naturally regenerated swards. In the short term, larger and more species-rich invertebrate assemblages were fostered on unmanaged Margins than on those managed by cutting. The timing of cutting was critical, with mid-summer cutting having the most persistent, negative effects on invertebrates, while cutting in spring and autumn was generally less damaging and may help maintain sward species richness. Fallowed land (set-aside) configured as blocks rather than Margins constituted qualitatively different habitats for invertebrates. Margin width had complex effects on invertebrate abundance and species richness. Boundary hedgerows increased numbers of most invertebrate groups in the adjacent Margin. The chapter suggests that blanket management approaches for invertebrates at the farm scale are not optimal. A diverse farmed landscape, with Margins of different sizes and different sward structures, will provide for the different ecological requirements of invertebrate populations, and promote their diversity in the characteristically unstable environment of arable systems.
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Manipulating the abundance of Lepthyphantes tenuis (Araneae: Linyphiidae) by Field Margin management
Agriculture Ecosystems & Environment, 2002Co-Authors: James R Bell, Ruth E. Feber, Paul J. Johnson, Helen Lawton Smith, Clive Hambler, Alison J Haughton, Fran H Tattersall, Barbara H Hart, Will Manley, David W. MacdonaldAbstract:Populations of the linyphiid spider Lepthyphantes tenuis were sampled in Field Margins in May, July and September in 1990–1991 and 1995–1996. Field Margins were subjected to 10 grassland management regimes, which included the effects of spraying the herbicide glyphosate, cutting, leaving vegetation in situ after the cut, sowing and a control. These treatments were randomised within six complete blocks at the University of Oxford’s farm at Wytham. Cutting vegetation had an immediate effect on number of L. tenuis in both spring and summer. Cutting Margins in summer had a more persistent effect on populations of L. tenuis than did cutting Margins in spring. The effect of cutting was not mitigated by leaving cut vegetation in situ, but no cutting ensured higher number of L. tenuis in Margins, an indication that height and structural complexity of grassland vegetation were important in determining population size. Significantly fewer spiders were found in July and September plots which had been sprayed with herbicide in late June/early July. However, spider numbers were not affected by glyphosate application when samples were taken nearly a year later. Sowing a wildflower seed mixture had no significant effects on number of this generalist predator although other invertebrate groups did benefit. Field Margins provided an excellent source habitat for L. tenuis. Habitats that border crop Fields acted as a refugia for many other beneficial invertebrates and should be retained as an important component of the agricultural landscape.
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The effects of arable Field Margin management on the abundance and species richness of Araneae (spiders)
Ecography, 1998Co-Authors: M. Baines, Paul J. Johnson, David W. Macdonald, Clive Hambler, Helen Lawton SmithAbstract:The effects of ten different management regimes on the abundance and species richness of Araneae on pre-existing and newly expanded zones of Field Margins surrounding arable Fields are compared in a large-scale experiment conducted between 1987 and 1991. Most of the management regimes involved varying the timing and frequency with which the Field Margins were cut. There was no evidence of consistent temporal trends in the abundance and species richness of Araneae on either the existing or expanded zones of the Field Margins during the first four years of the experiment. However, lowest numbers were recorded before expansion of the Margins in 1987, and highest numbers in the final sample, in 1991. Araneae remained less abundant, and less species rich, on the newly expanded than on the existing zones of the Field Margins four years after they were ' set-aside'. Cutting reduced both abundance and species richness. Regimes which included cutting in mid-summer had a greater impact which persisted for longer than did those involving cutting in spring and autumn. Removal of cut material was associated with lower species richness than leaving it in situ. Sowing the Margins with a wild flower seed mixture was associated with increased abundance and species richness of Araneae. Annual spraying with a broad-spectrum, non-persistent herbicide reduced the abundance of Araneae but the effect was not detectable until several months after the application of the spray. Both the species richness and abundance of Araneae were positively correlated with a measure of vegetation height made on the Field Margins in September, on both the pre-existing and newly expanded zones of the Margins. The extent to which management practices which benefit Araneae are compatible with both the management requirements for various other taxa, and the overriding constraint of effective pernicious weed control on Field Margins, is discussed.
Belmain, Steven R. - One of the best experts on this subject based on the ideXlab platform.
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Insect pollination is important in a smallholder bean farming system
'PeerJ', 2020Co-Authors: Belmain, Steven R., Stevenson, Philip C., Arnold, Sarah E.j., Gurr, Geoff M., Elisante Filemon, Xie Gang, Darbyshire Iain, Ndakidemi PatrickAbstract:Background Many crops are dependent on pollination by insects. Habitat management in agricultural landscapes can support pollinator services and even augment crop production. Common bean (Phaseolus vulgaris L.) is an important legume for the livelihoods of smallholder farmers in many low-income countries, particularly so in East Africa. While this crop is autogamous, it is frequently visited by pollinating insects that could improve yields. However, the value of pollination services to common beans (Kariasii) yield is not known. Methods We carried out pollinator-exclusion experiments to determine the contribution of insect pollinators to bean yields. We also carried out a fluorescent-dye experiment to evaluate the role of Field Margins as refuge for flower-visitors. Results Significantly higher yields, based on pods per plant and seeds per pod, were recorded from open-pollinated and hand-pollinated flowers compared to plants from which pollinators had been excluded indicating that flower visitors contribute significantly to bean yields. Similarly, open and hand-pollinated plants recorded the highest mean seed weight. Extrapolation of yield data to Field scale indicated a potential increase per hectare from 681 kg in self-pollinated beans to 1,478 kg in open-pollinated beans indicating that flower visitors contributed significantly to crop yield of beans. Our marking study indicated that flower-visiting insects including bees, flies and lepidopterans moved from the Field Margin flowers into the bean crop. Overall, these results show that insect pollinators are important for optimising bean yields and an important food security consideration on smallholder farms. Field Margin vegetation also provides habitat for flower-visiting insects that pollinate beans. Hence, non-crop habitats merit further research focusing on establishing which Field Margin species are most important and their capacity to support other ecosystem services such as natural pest regulation or even pests
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Multiple ecosystem services from Field Margin vegetation for ecological sustainability in agriculture: scientific evidence and knowledge gaps
'PeerJ', 2019Co-Authors: Mkenda, Prisila A., Ndakidemi, Patrick A., Mbega Ernest, Stevenson, Philip C., Arnold, Sarah E.j., Gurr, Geoff M., Belmain, Steven R.Abstract:Background: Field Margin and non-crop vegetation in agricultural systems are potential ecosystem services providers because they offer semi-natural habitats for both below and above ground animal groups such as soil organisms, small mammals, birds and arthropods that are service supplying units. They are considered as a target area for enhancing farm biodiversity. Methodology: To explore the multiple potential benefits of these semi-natural habitats and to identify research trends and knowledge gaps globally, a review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 235 publications from the year 2000 to 2016 in the Scopus and Web of Science databases were reviewed. Results: The literature showed an increasing trend in the number of published articles over time with European studies leading in the proportion of studies conducted, followed by North America, Asia, South America, Africa and Australia. Several functional groups of organisms were studied from Field Margin and non-crop vegetation around agricultural lands including natural enemies (37%), insect pests (22%), birds (17%), pollinators (16%), soil macro fauna (4%) and small mammals (4%). Ecosystem services derived from the Field Margin included natural pest regulation, pollination, nutrient cycling and reduced offsite erosion. Some Field Margin plants were reported to host detrimental crop pests, a major ecosystem dis-service, potentially leading to increased pest infestation in the Field. Conclusion: The majority of studies revealed the importance of Field Margin and non-crop vegetation around arable Fields in enhancing ecosystem biodiversity. Promotion of Field Margin plants that selectively enhance the population of beneficial organisms would support sustainable food security rather than simply boosting plant diversity. Our analyses also highlight that agro-ecological studies remain largely overlooked in some regions
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Extracts from Field Margin weeds provide economically viable and environmentally benign pest control compared to synthetic pesticides
'Public Library of Science (PLoS)', 2015Co-Authors: Mkenda Prisila, Stevenson, Philip C., Ndakidemi Patrick, Mwanauta Regina, Mtei Kelvin, Belmain, Steven R.Abstract:Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under Field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris) that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders). Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the Marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin) and T. diversifolia (the sesquiterpene lactone tagitinin A). Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the Field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides