171 resultados para Agricultural pests.
Resumo:
Integrated Arable Farming Systems (IAFS) projects utilise a range of novel and different farming techniques, often associated with optimising or reducing the use of inputs. Here, data is presented from the LINK-IFS project which suggests that, although input levels are being reduced, the overall profitability of the system can be maintained. The effect of thus reduction in inputs, however, in terms of impact on key environmental indicators is unclear.
Resumo:
In this article we investigate the effects of the European CAP reform on a selection of arable crops in England, both at a regional and national level. The results show that the CAP reform will push farmers to adjust to the new market conditions, which will cause a further restructuring of the English agricultural business sector. Our results show that, under the new market conditions, economically-small farms will increase their output by allocating more land to cereals, whereas economically-large farms will need to decrease land allocated to cereals to reduce production costs and achieve better returns.
Resumo:
The study was undertaken to investigate how willing would farmers be to pay for agricultural extension service in Nigeria. A multistage random sampling technique was used to select 268 respondents. Results showed that most farmers (95.1 per cent) were willing to pay for improved extension service as long as the service remained relevant to their needs. Farmers were willing to pay N1000 annually as their own share of the service cost. The most important factors that influenced farmers’ willingness to pay were states of origin, items originally paid for, major occupation, minor occupation, number of years in school and sale of farm produce.
Resumo:
Why do people engage in artisanal and small-scale mining (ASM) – labour-intensive mineral extraction and processing activity – across sub-Saharan Africa? This paper argues that ‘agricultural poverty’, or hardship induced by an over-dependency on farming for survival, has fuelled the recent rapid expansion of ASM operations throughout the region. The diminished viability of smallholder farming in an era of globalization and overreliance on rain-fed crop production restricted by seasonality has led hundreds of thousands of rural African families to ‘branch out’ into ASM, a move made to secure supplementary incomes. Experiences from Komana West in Southwest Mali and East Akim District in Southeast Ghana are drawn upon to illustrate how a movement into the ASM economy has impacted farm families, economically, in many rural stretches of sub-Saharan Africa.
Resumo:
Aphids are important pests of spring cereals and their abundance and the impact of their natural enemies may be influenced by fertilizer regime.2We conducted a 2-year field study investigating the effects of organic slow-release and conventional fertilizers on cereal aphids, hymenopteran parasitoids and syrphid predators and considered how the effects of fertilizers on barley morphology and colour might influence these species.3Barley yield was greater in conventionally fertilized pots. Barley morphology was also affected by treatment: vegetative growth was greater under conventional treatments. Barley receiving organic fertilizers or no fertilizer was visually more attractive to aphids compared with plants receiving conventional fertilizers.4Aphids were more abundant in conventionally fertilized barley but the reason for this increased abundance was species specific. Metopolophium dirhodum was responding to fertilizer effects on plant morphology, whereas Rhopalosiphum padi was sensitive to the temporal availability of nutrients.5Syrphid eggs were more numerous in conventionally fertilized pots, whereas the response of parasitoids appeared to be dependent on the abundance of aphids, although the number of parasitoid mummies was low in both years.6This research shows that the fertilizer treatment used can affect numerous characteristics of plant growth and colour, which can then influence higher trophic levels. This knowledge might be used to make more informed fertilizer application choices.
Resumo:
The impact of parasitoids on pests varies between conventional and low-intensity agricultural systems. Although the impacts on parasitoid natural enemies of many practices within these agricultural systems are well understood, the role of fertilisers has been less well studied. The effects of organic-based and conventional fertilisers on Hordeum vulgare L. (Poaceae), the aphid Metopolophium dirhodum Walker (Hemiptera: Aphididae), and its parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) was investigated using cage release experiments and measures of aphid and parasitoid fitness were taken. Barley tiller number and aphid weight were increased by fertilisers, particularly under conventional treatments. Adult parasitoid size correlated positively with that of the host, M. dirhodum, whereas percentage parasitism was not affected by fertiliser treatment or host size. The results suggest that the increased parasitoid impact observed in some low-intensity or organic systems is not a direct result of fertiliser treatment. Our results indicate that fertiliser treatments that improve cereal-aphid fitness will improve parasitoid fitness as measured by parasitoid size but may not influence percentage parasitism.
Resumo:
Food security is one of this century’s key global challenges. By 2050 the world will require increased crop production in order to feed its predicted 9 billion people. This must be done in the face of changing consumption patterns, the impacts of climate change and the growing scarcity of water and land. Crop production methods will also have to sustain the environment, preserve natural resources and support livelihoods of farmers and rural populations around the world. There is a pressing need for the ‘sustainable intensifi cation’ of global agriculture in which yields are increased without adverse environmental impact and without the cultivation of more land. Addressing the need to secure a food supply for the whole world requires an urgent international effort with a clear sense of long-term challenges and possibilities. Biological science, especially publicly funded science, must play a vital role in the sustainable intensifi cation of food crop production. The UK has a responsibility and the capacity to take a leading role in providing a range of scientifi c solutions to mitigate potential food shortages. This will require signifi cant funding of cross-disciplinary science for food security. The constraints on food crop production are well understood, but differ widely across regions. The availability of water and good soils are major limiting factors. Signifi cant losses in crop yields occur due to pests, diseases and weed competition. The effects of climate change will further exacerbate the stresses on crop plants, potentially leading to dramatic yield reductions. Maintaining and enhancing the diversity of crop genetic resources is vital to facilitate crop breeding and thereby enhance the resilience of food crop production. Addressing these constraints requires technologies and approaches that are underpinned by good science. Some of these technologies build on existing knowledge, while others are completely radical approaches, drawing on genomics and high-throughput analysis. Novel research methods have the potential to contribute to food crop production through both genetic improvement of crops and new crop and soil management practices. Genetic improvements to crops can occur through breeding or genetic modifi cation to introduce a range of desirable traits. The application of genetic methods has the potential to refi ne existing crops and provide incremental improvements. These methods also have the potential to introduce radical and highly signifi cant improvements to crops by increasing photosynthetic effi ciency, reducing the need for nitrogen or other fertilisers and unlocking some of the unrealised potential of crop genomes. The science of crop management and agricultural practice also needs to be given particular emphasis as part of a food security grand challenge. These approaches can address key constraints in existing crop varieties and can be applied widely. Current approaches to maximising production within agricultural systems are unsustainable; new methodologies that utilise all elements of the agricultural system are needed, including better soil management and enhancement and exploitation of populations of benefi cial soil microbes. Agronomy, soil science and agroecology—the relevant sciences—have been neglected in recent years. Past debates about the use of new technologies for agriculture have tended to adopt an either/or approach, emphasising the merits of particular agricultural systems or technological approaches and the downsides of others. This has been seen most obviously with respect to genetically modifi ed (GM) crops, the use of pesticides and the arguments for and against organic modes of production. These debates have failed to acknowledge that there is no technological panacea for the global challenge of sustainable and secure global food production. There will always be trade-offs and local complexities. This report considers both new crop varieties and appropriate agroecological crop and soil management practices and adopts an inclusive approach. No techniques or technologies should be ruled out. Global agriculture demands a diversity of approaches, specific to crops, localities, cultures and other circumstances. Such diversity demands that the breadth of relevant scientific enquiry is equally diverse, and that science needs to be combined with social, economic and political perspectives. In addition to supporting high-quality science, the UK needs to maintain and build its capacity to innovate, in collaboration with international and national research centres. UK scientists and agronomists have in the past played a leading role in disciplines relevant to agriculture, but training in agricultural sciences and related topics has recently suffered from a lack of policy attention and support. Agricultural extension services, connecting farmers with new innovations, have been similarly neglected in the UK and elsewhere. There is a major need to review the support for and provision of extension services, particularly in developing countries. The governance of innovation for agriculture needs to maximise opportunities for increasing production, while at the same time protecting societies, economies and the environment from negative side effects. Regulatory systems need to improve their assessment of benefits. Horizon scanning will ensure proactive consideration of technological options by governments. Assessment of benefi ts, risks and uncertainties should be seen broadly, and should include the wider impacts of new technologies and practices on economies and societies. Public and stakeholder dialogue—with NGOs, scientists and farmers in particular—needs to be a part of all governance frameworks.
Resumo:
Scintillometry is an established technique for determining large areal average sensible heat fluxes. The scintillometer measurement is related to sensible heat flux via Monin–Obukhov similarity theory, which was developed for ideal homogeneous land surfaces. In this study it is shown that judicious application of scintillometry over heterogeneous mixed agriculture on undulating topography yields valid results when compared to eddy covariance (EC). A large aperture scintillometer (LAS) over a 2.4 km path was compared with four EC stations measuring sensible (H) and latent (LvE) heat fluxes over different vegetation (cereals and grass) which when aggregated were representative of the LAS source area. The partitioning of available energy into H and LvE varied strongly for different vegetation types, with H varying by a factor of three between senesced winter wheat and grass pasture. The LAS derived H agrees (one-to-one within the experimental uncertainty) with H aggregated from EC with a high coefficient of determination of 0.94. Chronological analysis shows individual fields may have a varying contribution to the areal average sensible heat flux on short (weekly) time scales due to phenological development and changing soil moisture conditions. Using spatially aggregated measurements of net radiation and soil heat flux with H from the LAS, the areal averaged latent heat flux (LvELAS) was calculated as the residual of the surface energy balance. The regression of LvELAS against aggregated LvE from the EC stations has a slope of 0.94, close to ideal, and demonstrates that this is an accurate method for the landscape-scale estimation of evaporation over heterogeneous complex topography.
Resumo:
This paper applies a reading of the postmodernisation of law to the incremental reform of agricultural holdings legislation over the last century. In charting the shifting legal basis of agricultural tenancies, from ‘black letter’ positivism to the cultural contextuality of sumptuary law, the paper theorises that the underlying political imperative has been allied to the changing significance of property ownership and use. Rather than reflecting the long-term official desire to maintain the let sector in British agriculture, however, the paper argues that this process has had other aims. In particular, it has been about an annexation of law to legitimise the retention of landowner power while presenting a rhetorical ‘democratisation’ of farming, away from its plutocratic associations and towards a new narrative of ‘depersonalised’ business.
Resumo:
This paper presents an overview of the European Union involvement in agricultural restructuring. By way of introduction it looks at the processes of farm replication operating in Europe and the forces behind them. It then considers the wider application of EU measures in each Member State and how they interrelate with the national property laws and social customs. In conclusion the paper appraises the restructuring policies by examining the balance between legitimising the concentration of property rights amongst a minority and the fragmentation of estates between the majority.
Resumo:
Agricultural tenancies arising after 1st September 1995 are mostly governed by the Agricultural Tenancies Act 1995. As such, tenants under this Act do not benefit from the degree of protection conferred on tenancies already in existence, which remain under the Agricultural Holdings Act 1986. Section 4 of the 1995 Act seeks to protect those tenancies which subsequently inadvertently undergo a surrender and regrant and which would otherwise lose the protection of the 1986 Act. This paper seeks to investigate, by relating recent case law and statute to the situation of agricultural tenancies, the occasions where surrender and regrant might occur and whether in such instances the protection of the 1986 Act will be lost.
Resumo:
This paper seeks to analyse and discuss, from the perspective of the owners of agricultural land, the main changes to the Capital Gains Tax regime introduced in the Budget of March 1998 and contained in the Finance Act 1998. The immediate replacement of indexation with a new Taper relief is examined, along with the phasing out of Retirement relief, and the interaction of Taper relief with Rollover relief.
Resumo:
This paper sets out an example of a standard agricultural tenancy, being one creating a tenancy from year to year and consequently covered by the agricultural holdings legislation. A facing-page commentary gives a clause-by-clause analysis of the agreement, the implications of each provision being discussed in the light of the law of contract, agricultural holdings legislation and, where appropriate, subsequent caselaw.
Marriage value and scarcity in agricultural rents: a discussion of the findings in Childers v Ankers
Resumo:
Formal statutory guidance to arbitrators involved in settling disputes over rents for agricultural holdings is contained in the Agricultural Holdings Act 1986. The particular features of the agricultural letting market raise valuation problems which the Act itself has failed to satisfactorily address, most notably the degree to which marriage value and scarcity should be taken into account. The 1995 Court of Appeal case of Childers v Anker addresses several of the key issues. This paper seeks to explore the findings and practical implications of the case for rental valuers and arbitrators. It argues that sitting tenants may be seriously disadvantaged by the court's judgements, not least by having to pay rents on review which reflect elements of marriage value and possibly scarcity value.
Resumo:
An experimental survey was undertaken to explore the links between the characteristics of a moral issue, the degree of moral intensity/moral imperative associated with the issue (Jones, 1991), and people's stated willingness to pay (wtp) for policy to address the issue. Two farm animal welfare issues were chosen for comparison and the contingent valuation method was used to elicit people's wtp. The findings of the survey suggest that increases in moral characteristics do appear to result in an increase in moral intensity and the degree of moral imperative associated with an issue. Moreover, there was a positive link between moral intensity/moral imperative associated with an issue and people's stated wtp for policy to address the issue. The paper discusses the relevance of the findings of the survey in the context of the debate concerning the relationship between moral and economic values and the use of the contingent valuation method to estimate people's wtp of policy options with moral dimensions.