988 resultados para agricultural impacts


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This paper examines the challenges of water supply in agriculture, with particular emphasis on requirements of field crops, including maize. It places the issue of water supply to agriculture in the context of increasing demands for water from alternatives users, declining quality water, pressure of increasing population, all of which are placing stresses on water availability at local, regional and national levels. The paper also examines existing freshwater resources and the potential impact of climate change on water supply and distribution and consequential impact on water stress incidence in various parts of the globe. It examines competition for water in both industrialized and developing countries, with particular emphasis on the impacts on agriculture and food supplies. The challenge of water use efficiency (WUE) in agriculture is explored with discussion of agronomic, economic and physiological WUE concepts, with specific reference to maize.

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Global problems, rapid and massive regional changes in the 21st century call for genuine long-term, awareness, planning and well focused actions from both national governments and international organizations. This book wishes to contribute to building an innovative path of strategic views in handling the diverse challenges, and more emphatically, the economic impacts of climate change. Although the contributors of this volume represent several approaches, they all rely on some common grounds such as the costbenefit analysis of mitigation and adaptation, and on the need to present an in-depth theoretical and practical dimension. The research accounted for in this book tried to integrate and confront various types of economics approaches and methods, as well as knowledge from game theory to country surveys, from agricultural adaptation to weather bonds, from green tax to historical experience of human adaptation. The various themes and points of views do deserve the attention of the serious academic reader interested in the economics of climate change. We hope to enhance the spread of good solutions resulting from world wide disputes and tested strategic decisions. WAKE UP! It is not just the polar bears' habitat that is endangered, but the entire human form of life.

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Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci.

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Global environmental changes (GEC) such as climate change (CC) and climate variability have serious impacts in the tropics, particularly in Africa. These are compounded by changes in land use/land cover, which in turn are driven mainly by economic and population growth, and urbanization. These factors create a feedback loop, which affects ecosystems and particularly ecosystem services, for example plant-insect interactions, and by consequence agricultural productivity. We studied effects of GEC at a local level, using a traditional coffee production area in greater Nairobi, Kenya. We chose coffee, the most valuable agricultural commodity worldwide, as it generates income for 100 million people, mainly in the developing world. Using the coffee berry borer, the most serious biotic threat to global coffee production, we show how environmental changes and different production systems (shaded and sun-grown coffee) can affect the crop. We combined detailed entomological assessments with historic climate records (from 1929-2011), and spatial and demographic data, to assess GEC's impact on coffee at a local scale. Additionally, we tested the utility of an adaptation strategy that is simple and easy to implement. Our results show that while interactions between CC and migration/urbanization, with its resultant landscape modifications, create a feedback loop whereby agroecosystems such as coffee are adversely affected, bio-diverse shaded coffee proved far more resilient and productive than coffee grown in monoculture, and was significantly less harmed by its insect pest. Thus, a relatively simple strategy such as shading coffee can tremendously improve resilience of agro-ecosystems, providing small-scale farmers in Africa with an easily implemented tool to safeguard their livelihoods in a changing climate.

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Abstract The potential impacts of climate change and environmental variability are already evident in most parts of the world, which is witnessing increasing temperature rates and prolonged flood or drought conditions that affect agriculture activities and nature-dependent livelihoods. This study was conducted in Mwanga District in the Kilimanjaro region of Tanzania to assess the nature and impacts of climate change and environmental variability on agriculture-dependent livelihoods and the adaptation strategies adopted by small-scale rural farmers. To attain its objective, the study employed a mixed methods approach in which both qualitative and quantitative techniques were used. The study shows that farmers are highly aware of their local environment and are conscious of the ways environmental changes affect their livelihoods. Farmers perceived that changes in climatic variables such as rainfall and temperature had occurred in their area over the period of three decades, and associated these changes with climate change and environmental variability. Farmers’ perceptions were confirmed by the evidence from rainfall and temperature data obtained from local and national weather stations, which showed that temperature and rainfall in the study area had become more variable over the past three decades. Farmers’ knowledge and perceptions of climate change vary depending on the location, age and gender of the respondents. The findings show that the farmers have limited understanding of the causes of climatic conditions and environmental variability, as some respondents associated climate change and environmental variability with social, cultural and religious factors. This study suggests that, despite the changing climatic conditions and environmental variability, farmers have developed and implemented a number of agriculture adaptation strategies that enable them to reduce their vulnerability to the changing conditions. The findings show that agriculture adaptation strategies employ both planned and autonomous adaptation strategies. However, the study shows that increasing drought conditions, rainfall variability, declining soil fertility and use of cheap farming technology are among the challenges that limit effective implementation of agriculture adaptation strategies. This study recommends further research on the varieties of drought-resilient crops, the development of small-scale irrigation schemes to reduce dependence on rain-fed agriculture, and the improvement of crop production in a given plot of land. In respect of the development of adaptation strategies, the study recommends the involvement of the local farmers and consideration of their knowledge and experience in the farming activities as well as the conditions of their local environment. Thus, the findings of this study may be helpful at various levels of decision making with regard to the development of climate change and environmental variability policies and strategies towards reducing farmers’ vulnerability to current and expected future changes.

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Objectives: 1) To document the extent of ponded pastures and other pondage systems in and adjacent to coastal wetlands on the central coast of Queensland. 2) To assess the movement, growth and survival of barramundi in ponded pastures. 3) To assess the utilisation by barramundi of ponded pastures and wetlands dominated by exotic grass species. 4) To identify appropriate wetland management strategies for facilitating barramundi movement and survival in ponded pastures and other pondage systems. 5) To document the species composition of finfish populations and their relative abundance in ponded pastures.

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Improved agricultural productivity, and reduction of environmental impacts, require studies of the interactions between different soil components. Fertilizers marketed as "organic" or "natural", such as peats or humic substances (HS) extracted from peats, are enriched with macro and micronutrients that, according to the manufacturers, are released to the plant in accordance with its needs. This work investigates the complexation capacity of HS for macro and micronutrient metal species, considering the competition, for HS complexation sites, between non-essential metals (aluminium and lead), present in the soil, and the nutrients. Humic substances were found to possess strong affinities for Pb(II) and Al(III), forming stable complexes, with concomitant release of complexed nutrients. Although HS are already used commercially as organic fertilizers, further studies of methods of HS enrichment, aimed at avoiding losses, are highly desirable from environmental and economic perspectives. (C) 2009 Elsevier B.V. All rights reserved.

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Reforestation will have important consequences for the global challenges of mitigating climate change, arresting habitat decline and ensuring food security. We examined field-scale trade-offs between carbon sequestration of tree plantings and biodiversity potential and loss of agricultural land. Extensive surveys of reforestation across temperate and tropical Australia (N=1491 plantings) were used to determine how planting width and species mix affect carbon sequestration during early development (< 15 year). Carbon accumulation per area increased significantly with decreasing planting width and with increasing proportion of eucalypts (the predominant over-storey genus). Highest biodiversity potential was achieved through block plantings (width>40m) with about 25% of planted individuals being eucalypts. Carbon and biodiversity goals were balanced in mixed-species plantings by establishing narrow belts (width<20m) with a high proportion (>75%) of eucalypts, and in monocultures of mallee eucalypt plantings by using the widest belts (ca. 6-20m). Impacts on agriculture were minimized by planting narrow belts (ca. 4m) of mallee eucalypt monocultures, which had the highest carbon sequestering efficiency. A plausible scenario where only 5% of highly-cleared areas (<30% native vegetation cover remaining) of temperate Australia are reforested showed substantial mitigation potential. Total carbon sequestration after 15 years was up to 25Mt CO2-e year-1 when carbon and biodiversity goals were balanced and 13Mt CO2-e year-1 if block plantings of highest biodiversity potential were established. Even when reforestation was restricted to marginal agricultural land (<$2000ha-1 land value, 28% of the land under agriculture in Australia), total mitigation potential after 15 years was 17-26Mt CO2-e year-1 using narrow belts of mallee plantings. This work provides guidance on land use to governments and planners. We show that the multiple benefits of young tree plantings can be balanced by manipulating planting width and species choice at establishment. In highly-cleared areas, such plantings can sequester substantial biomass carbon while improving biodiversity and causing negligible loss of agricultural land.

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Australia's northern savannas are one of the few remaining large and mostly intact natural areas on Earth. However, their biodiversity and ecosystem values could be threatened if proposed agricultural development proceeds. Through land-use change scenarios, we explored trade-offs and synergies among biodiversity conservation, carbon farming and agriculture production in northern Australia. We found that if all suitable soils were converted to agriculture, habitat at unique recorded locations of three species would disappear and 40 species and vegetation communities could lose more than 50% of their current distributions. Yet, strategically considering agriculture and biodiversity outcomes leads to zoning options that could yield >56,000 km2 of agricultural development with a significantly lower impact on biodiversity values and carbon farming. Our analysis provides a template for policy-makers and planners to identify areas of conflict between competing land-uses, places to protect in advance of impacts, and planning options that balance agricultural and conservation needs.

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This paper is an analysis of emic versus etic approaches to climate change resiliency, taking as a case study the traditional ceremony performed by farmers in eastern Flores, Indonesia to rid their fields of rats. This paper begins by providing a theoretical framework discussion on the dominant etic and emic academic research on monsoons and climate change impacts on agriculture. The rat ceremony performed in villages throughout East Flores is a local custom used to rid agricultural fields of pests—often rats—that come from the surrounding forests to feed on the agricultural crops when the rains become erratic. This paper argues that analyzing the rat ceremony through an emic lens allows for better future resiliency to monsoon shifts due to climate change. It is argued that the rat ceremony demonstrates a way in which community resiliency is strengthened by an adaptive approach that supports an already existing community ceremony that emphasizes two essential tenets: community solidarity and coexistence with nature. Both tenets directly promote community resiliency. An explicit emphasis on emic approaches to climate change challenges could help re-define how resiliency is understood and supported within vulnerable communities such as rural villages.

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Procambarus clarkii is currently recorded from 16 European territories. On top of being a vector of crayfish plague, which is responsible for large-scale disappearance of native crayfish species, it causes severe impacts on diverse aquatic ecosystems, due to its rapid life cycle, dispersal capacities, burrowing activities and high population densities. The species has even been recently discovered in caves. This invasive crayfish is a polytrophic keystone species that can exert multiple pressures on ecosystems. Most studies deal with the decline of macrophytes and predation on several species (amphibians, molluscs, and macroinvertebrates), highlighting how this biodiversity loss leads to unbalanced food chains. At a management level, the species is considered as (a) a devastating digger of the water drainage systems in southern and central Europe, (b) an agricultural pest in Mediterranean territories, consuming, for example, young rice plants, and (c) a threat to the restoration of water bodies in north-western Europe. Indeed, among the high-risk species, P. clarkii consistently attained the highest risk rating. Its negative impacts on ecosystem services were evaluated. These may include the loss of provisioning services such as reductions in valued edible native species of regulatory and supporting services, inducing wide changes in ecological communities and increased costs to agriculture and water management. Finally, cultural services may be lost. The species fulfils the criteria of the Article 4(3) of Regulation (EU) No 1143/2014 of the European Parliament (species widely spread in Europe and impossible to eradicate in a cost-effective manner) and has been included in the “Union List”. Particularly, awareness of the ornamental trade through the internet must be reinforced within the European Community and import and trade regulations should be imposed to reduce the availability of this high-risk species.

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A strategic planning process has been implemented at the Brazilian Agricultural Research Agency (Embrapa) to introduce sustainable development objectives in all steps of agricultural Research and Development. An essential component of the institutional mission statement hence devised has called for the systematic assessment of social and environmental impacts (in addition to the traditionally studied economic ones) of all technology innovations resulting from R&D. The proposed approach emphasizes the interest of promoting close interaction between R&D teams and technology-adopting producers, under actual field contexts, in order to improve both the technology development and the demand probing processes. Given the multiplicity of technological applications ensuing from Embrapa?s very broad research encompassment, and the variety of environmental and productive contexts involved, a customized impact assessment system has been proposed. Directed at the appraisal of agricultural technology development research projects (ex-ante) as well as their ensuing innovations (ex-post), the Ambitec-Agro System comprises a set of integrated socio-environmental indicators, constructed in modules suited to Agricultural, Animal husbandry, and Agro-industrial activities, besides a specific module for Social Impact Assessment. The system has been routinely applied in technology appraisal in all of Embrapa?s Units, as a basis for their institutional performance evaluations, and toward the formulation of the annual Social Balance Report. Following the inception of this institutional technology appraisal initiative, several methodological innovations have been proposed within Embrapa, including technical improvements and applicability adaptations of the Ambitec-Agro system, and approaches to further-reaching objectives, such as the sustainable development of rural communities, and the environmental management of agricultural activities.

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Monitoring agricultural crops constitutes a vital task for the general understanding of land use spatio-temporal dynamics. This paper presents an approach for the enhancement of current crop monitoring capabilities on a regional scale, in order to allow for the analysis of environmental and socio-economic drivers and impacts of agricultural land use. This work discusses the advantages and current limitations of using 250m VI data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for this purpose, with emphasis in the difficulty of correctly analyzing pixels whose temporal responses are disturbed due to certain sources of interference such as mixed or heterogeneous land cover. It is shown that the influence of noisy or disturbed pixels can be minimized, and a much more consistent and useful result can be attained, if individual agricultural fields are identified and each field's pixels are analyzed in a collective manner. As such, a method is proposed that makes use of image segmentation techniques based on MODIS temporal information in order to identify portions of the study area that agree with actual agricultural field borders. The pixels of each portion or segment are then analyzed individually in order to estimate the reliability of the temporal signal observed and the consequent relevance of any estimation of land use from that data. The proposed method was applied in the state of Mato Grosso, in mid-western Brazil, where extensive ground truth data was available. Experiments were carried out using several supervised classification algorithms as well as different subsets of land cover classes, in order to test the methodology in a comprehensive way. Results show that the proposed method is capable of consistently improving classification results not only in terms of overall accuracy but also qualitatively by allowing a better understanding of the land use patterns detected. It thus provides a practical and straightforward procedure for enhancing crop-mapping capabilities using temporal series of moderate resolution remote sensing data.