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	Provedor de dados AgEcon (1) Autor Dolberg, Frands (1) Palavra-chave Food Security and Poverty (1) Livelihoods (1) Livestock Production/Industries (1) Poultry (1) Poverty alleviation (1) Pro-poor livestock policy (1) Mais... Tipo do documento Working or Discussion Paper (1) Ano 2003 (1) País United States (1) Idioma Inglês (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 37 Primeira ... 1 2 ... Última Water Stress in the Production and Quality of Bidens pilosa and Raphanus raphanistrum Seeds Planta Daninha PEREIRA,M.R.R.; MARTINS,C.C.; SILVA JR.,A.C.; MARTINS,D.. ABSTRACT: Plants in soils with low water availability may present a reduction of their leaf area and photosynthetic rate, as well as lower assimilated compound supply for seeds. Knowing the physiological quality and seed production of weeds generated under water deficit conditions can help understanding the survival and competition strategies of species. The objective of this work was to evaluate the effect of water stress on the production and germination of Bidens pilosa and Raphanus raphanistrum seeds. Plants were maintained in soils with different water potentials (-0.03, -0.07 and -1.5 MPa) throughout their cycle, until seed production, when they were harvested. Then, evaluations were performed to find out the number of seeds per plant and number of... Tipo: Info:eu-repo/semantics/article Palavras-chave: Germination; Vigor; Water availability. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100305 Possible Impacts of Climate Change on Mediterranean Irrigated Farming Systems AgEcon Dono, Gabriele; Cortignani, Raffaele; Doro, Luca; Ledda, Luigi; Roggero, PierPaolo; Giraldo, Luca; Severini, Simone. In the agricultural sector, climate change (CC) affects multiple weather variables at different stages of crop cycles. CC may influence the mean level or affect the distribution of events (e.g., rainfall, temperature). This work evaluates the economic impact of CC-related changes in multiple climatic components, and the resulting uncertainty. For this purpose, a three-stage discrete stochastic programming model is used to represents farm sector of an irrigated area of Italy and to examine the influence of CC on rainfall and on maximum temperature. These variables affect the availability of water for agriculture and the water requirements of irrigated crops. The states of nature, and their change, are defined more broadly than in previous analyses; this... Tipo: Conference Paper or Presentation Palavras-chave: Discrete stochastic programming model; Climate change; Water availability; Irrigation requirements; Farm Management; Resource /Energy Economics and Policy. Ano: 2011 URL: http://purl.umn.edu/114436 Urban wastewater: A valuable resource for agriculture - A case study from Haroonabad, Pakistan AgEcon van der Hoek, Wim; Ul Hassan, Mehmood; Ensink, Jeroen H.J.; Feenstra, Sabiena; Raschid-Sally, Liqa; Munir, Sarfraz; Aslam, Rizwan; Ali, Nazim; Hussain, Raheela; Matsuno, Yutaka. Farming communities in water-scarce regions increasingly practice the use of urban wastewater in agriculture. Untreated urban wastewater is generally considered unacceptable for direct use because of potential health risks. However, in many parts of the world, poor farmers in peri-urban areas use untreated wastewater. This situation is considered likely to continue even in the foreseeable future due to the high investment cost associated with the installation of treatment facilities. Tipo: Report Palavras-chave: Waste waters; Irrigation water; Water reuse; Economic analysis; Soil properties; Households; Water availability; Water use; Water quality; Groundwater; Public health; Risks; Case studies; Agribusiness; Agricultural and Food Policy; Consumer/Household Economics; Crop Production/Industries; Environmental Economics and Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Production Economics; Risk and Uncertainty. Ano: 2002 URL: http://purl.umn.edu/44566 Analysis of the Adoption of Irrigation Technologies Under Uncertain Water Availability AgEcon Escribano, Maria Jesus; Calatrava-Leyva, Javier. This paper analyses the adoption process of water-conserving irrigation technologies by a risk averse farmer in a context of uncertain water availability. Firstly, it is analytically shown that the increase in water efficiency that the new technology allows results in a decrease in the cost of the effective irrigation water applied, as well as in an increase in both effective water applied and crop production. It is also concluded that the optimal amount of irrigation water applied depends on individual risk preferences of the producer, on the variance and asymmetry of the cost of water applied, and on the elasticity of the marginal productivity of the effective water applied. Lastly, it is theoretically shown that an increase in the level of uncertainty... Tipo: Conference Paper or Presentation Palavras-chave: Irrigation technology; Adoption; Risk; Water availability; Research and Development/Tech Change/Emerging Technologies; Resource /Energy Economics and Policy; Q25; Q12; D81. Ano: 2005 URL: http://purl.umn.edu/24672 Institutional perspectives of land reclamation operations in Punjab: A case study of the Lower Chenab Canal (East) Circle Area AgEcon Bandaragoda, Don Jayatissa; Rehman, Saeed ur. The Directorate of Land Reclamation (DLR), which was set up in 1945, is a special unit of Punjab's Irrigation and Power Department for undertaking research and field operations to combat the problem of salinity. Approaching the end of five decades of existence, the directorate is yet to demonstrate its effectiveness in its assigned task; its inability to fully cope with the conditions of a fast changing irrigation environment makes this rather an illusive goal. In the selection of lands for reclamation, the Directorate is heavily dependent on the visual salinity survey (Thur Girdawari) carried out every year by the Irrigation Department's field staff. This visual survey appears to be a quick and cost-effective method of assessing surface salinity, but... Tipo: Working or Discussion Paper Palavras-chave: Land reclamation; Soil salinity; Irrigated sites; Irrigation canals; Irrigation water; Institutions; Legal aspects; Irrigation scheduling; Water availability; Irrigated farming; Case studies; Farm Management; Land Economics/Use. Ano: 1994 URL: http://purl.umn.edu/113011 Land and water productivity: trends across Punjab canal commands. AgEcon Tahir, Zubair; Habib, Zaigham. Tipo: Working or Discussion Paper Palavras-chave: Land use; Water use; Productivity; Indicators; Crop yield; Irrigation canals; Groundwater; Water availability; River basins; Rain; Crop Production/Industries; Land Economics/Use; Productivity Analysis; Resource /Energy Economics and Policy. Ano: 2000 URL: http://purl.umn.edu/92783 Water resources management in Afghanistan: The issues and options AgEcon Qureshi, Asad Sarwar. Tipo: Working or Discussion Paper Palavras-chave: Climate; Water availability; Crop yield; Rural economy; Water resources; Groundwater; Surface water; Irrigation systems; Irrigation canals; Dams; Water allocation; Water resource management; Crop Production/Industries; Resource /Energy Economics and Policy. Ano: 2002 URL: http://purl.umn.edu/92703 The groundwater economy of Pakistan AgEcon Qureshi, Asad Sarwar; Shah, Tushaar; Akhtar, Mujeeb. Tipo: Working or Discussion Paper Palavras-chave: Groundwater irrigation; Groundwater extraction; Utilization factor; Electric tubewells; Diesel tubewells; Groundwater economy; Groundwater markets; Groundwater pricing; Crop yield; Crop production; Farmers; Pumps; Irrigated farming; Water resources; Agricultural production; Groundwater development; Land use; Water availability; Farmers; Agribusiness; Agricultural and Food Policy; Agricultural Finance; Crop Production/Industries; Farm Management; Land Economics/Use; Resource /Energy Economics and Policy. Ano: 2003 URL: http://purl.umn.edu/92662 Spatial variation in water supply and demand across river basins of India AgEcon Amarasinghe, Upali A.; Sharma, Bharat R.; Aloysius, Noel; Scott, Christopher A.; Smakhtin, Vladimir U.; de Fraiture, Charlotte. India is a large country with regional differences in per-capita water supply and demand. Attempts to describe the water situation in India at a national level are often misleading due to the tremendous diversity in the water situation across the country. This Report analyzes the spatial variation of water supply and demand across river basins in India. The study identifies basins that are water-scarce because of inadequate water availability to meet the effective demand. It also identifies issues that are important for estimating the future water demand and for the formation of policy for future water-resources development and management. Tipo: Report Palavras-chave: Water supply; Water demand; River basins; Catchment areas; Water availability; Water scarcity; Estimation; Irrigation water; Domestic water; Population growth; Urbanization; Groundwater extraction; Crop production; Policy; Water transfer; India; Agricultural and Food Policy; Community/Rural/Urban Development; Consumer/Household Economics; Crop Production/Industries; Environmental Economics and Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Production Economics. Ano: 2004 URL: http://purl.umn.edu/52966 An evaluation of the economic impact of Climate Change through a three-stages Discrete Stochastic Programming model AgEcon Cortignani, Raffaele; Dono, Gabriele; Doro, Luca; Ledda, Luigi; Mazzapicchio, Graziano. The climate change in the agricultural sector acting on multiple weather variables at different times of the various crop cycles. In several cases by changing the mean level of variables (rainfall, temperature, etc..), in other cases by changing the distribution of events. This work provides an evaluation of the economic impact due to changes in multiple events, and to the associated uncertainty. For this reason, a classical two-stage stochastic programming model was extend into a three-stages model. The model is specified for an area of Sardinia, and examines the impact of climate change on rainfall and hence on the availability of water for agriculture, and on maximum temperatures and, therefore, on the requirements of some irrigated crops relevant to... Tipo: Conference Paper or Presentation Palavras-chave: Discrete Stochastic Programming Model; Climate change; Water availability; Irrigation requirements; Crop Production/Industries; Environmental Economics and Policy; Farm Management; Land Economics/Use; Research Methods/ Statistical Methods. Ano: 2010 URL: http://purl.umn.edu/109317 Chemical and physical-hydric characterisation of a red latosol after five years of management during the summer between-crop season Rev. Bras. Ciênc. Solo Silva,José Fausto Guimarães; Severiano,Eduardo da Costa; Costa,Kátia Aparecida de Pinho; Benites,Vinícius de Melo; Guimarães Júnnyor,Wellingthon da Silva; Bento,José Carlos. Agricultural production systems that include the production of mulch for no-tillage farming and structural improvement of the soil can be considered key measures for agricultural activity in the Cerrado region without causing environmental degradation. In this respect, our work aimed to evaluate the chemical and physical-hydric properties of a dystrophic Red Latosol (Oxisol) in the municipality of Rio Verde, Goias, Brazil, under different soil management systems in the between-crop season of soybean cultivation five years after first planting. The following conditions were evaluated: Brachiaria brizantha cv. Marandu as a cover crop during the between-crop season; Second crop of maize intercropped with Brachiaria ruziziensis; Second crop of grain alone in a... Tipo: Info:eu-repo/semantics/article Palavras-chave: Brachiaria; Crop succession; No-tillage; Least limiting water range; Water availability. Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000500023 HEAVY METALS AND MICRONUTRIENTS IN THE SOIL AND GRAPEVINE UNDER DIFFERENT IRRIGATION STRATEGIES Rev. Bras. Ciênc. Solo Oliveira,Vanessa de Souza; Lima,Augusto Miguel Nascimento; Salviano,Alessandra Monteiro; Bassoi,Luís Henrique; Pereira,Giuliano Elias. Soils under natural conditions have heavy metals in variable concentrations and there may be an increase in these elements as a result of the agricultural practices adopted. Transport of heavy metals in soil mainly occurs in forms dissolved in the soil solution or associated with solid particles, water being their main means of transport. In this context, the aim of this study was to evaluate the heavy metal and micronutrient content in the soil and in the grapevine plant and fruit under different irrigation strategies. The experiment was carried out in Petrolina, PE, Brazil. The treatments consisted of three irrigation strategies: full irrigation (FI), regulated deficit irrigation (RDI), and deficit irrigation (DI). During the period of grape maturation,... Tipo: Info:eu-repo/semantics/article Palavras-chave: Water availability; Nutrients; Grape. Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100162 Structural changes in latosols of the cerrado region: I - relationships between soil physical properties and least limiting water range Rev. Bras. Ciênc. Solo Severiano,Eduardo da Costa; Oliveira,Geraldo César de; Dias Júnior,Moacir de Souza; Costa,Katia Aparecida de Pinho; Silva,Fabiano Guimarães; Ferreira Filho,Silvio Marcos. The agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected from the B horizons of five oxidic Latosols representing the textural variability of the Latosols of the Cerrado biome. LLWR and other soil physical properties were determined at various soil... Tipo: Info:eu-repo/semantics/article Palavras-chave: Soil compaction; Degradation of agricultural soils; Soil penetration resistance; Water availability; Soil texture. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000300013 Productive characteristics and water use efficiency in cotton plants under different irrigation strategies AGRIAMBI Silva,Vamberto G. de F.; Andrade,Albericio P. de; Fernandes,Pedro D.; Silva,Ivandro de F. da; Azevedo,Carlos A. V. de; Araújo,Jucilene S.. Studies have been carried out on efficient water use in irrigation. The present study evaluates the yield of cotton plants (Gossypium hirsutum L. r. latifolium Hutch), and the use of water for different irrigation strategies. The experiment was conducted under greenhouse conditions, and the cultivar used was CNPA-7H Precocious grown in plastic pots; each pot contained 20 kg of dry soil. The irrigation strategies were selected by taking into account the available water in the soil, the irrigation frequency and the irrigation suppression during flowering and boll development. Water consumption, boll weight, yield, harvest index and water use efficiency were evaluated and the results showed that water consumption resulting from the irrigation strategies used... Tipo: Info:eu-repo/semantics/article Palavras-chave: Gossypium hirsutum; Phenology; Water availability; Water saving. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662010000500001 Response mechanisms of Brachiaria brizantha cultivars to water deficit stress R. Bras. Zootec. Santos,Patricia Menezes; Cruz,Pedro Gomes da; Araujo,Leandro Coelho de; Pezzopane,José Ricardo Macedo; Valle,Cacilda Borges do; Pezzopane,Cristiana de Gaspari. Two cultivars of Brachiaria brizantha (Hochst ex. A. Rich) Stapf. (Syn. Urochloa) were evaluated for their adaptation to water deficit and the stress response mechanisms in a greenhouse experiment. The experimental design was in completely randomized blocks with a 2 × 2 × 4 factorial arrangement. The Marandu and BRS Piatã cultivars were evaluated under two water availability conditions, with or without water restriction. The harvests were carried out 0, 7, 14 and 28 days after the start of water restriction. For both cultivars, the water deficit stress caused a reduction in shoot biomass and leaf area and an increase in the percentage of roots in the deeper soil layers. The B. brizantha cv. Marandu reached critical levels of leaf water potential in a... Tipo: Info:eu-repo/semantics/article Palavras-chave: BRS Piatã; Marandu; Osmotic potential; Water availability; Water potential. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013001100001 Variation in plant-animal interactions along an elevational gradient of moist forest in a semiarid area of Brazil Acta Botanica Diogo,Ivan Jeferson Sampaio; Martins,Fernando Roberto; Verola,Christiano Franco; Costa,Itayguara Ribeiro da. Pollination and dispersal are critical ecological processes that directly affect the reproductive success of plants and are important for understanding the structure of plant communities. We compiled data on pollination and dispersal syndromes of 406 plant species distributed among different elevations in Área de Proteção Ambiental da Serra de Baturité (APASB) in northeastern Brazil. We aim to determine how the dispersal and pollination of the flora in the mountainous rainforest of APASB are affected by climate, relief and growth form. We hypothesized that plant community is comprised of different ecological groups based on biotic and abiotic syndromes. Melittophily was the most common (57%) pollination syndrome followed by non-specialized and ornithophily... Tipo: Info:eu-repo/semantics/article Palavras-chave: Altitude; Humidity; Melittophily; Plant community; Topology; Water availability; Zoochory. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000100027 Trade-off between reservoir yield and evaporation losses as a function of lake morphology in semi-arid Brazil Anais da ABC (AABC) Campos,José N.B.; Lima Neto,Iran E.; Studart,Ticiana M.C.; Nascimento,Luiz S.V.. This study investigates the relationships between yield and evaporation as a function of lake morphology in semi-arid Brazil. First, a new methodology was proposed to classify the morphology of 40 reservoirs in the Ceará State, with storage capacities ranging from approximately 5 to 4500 hm3. Then, Monte Carlo simulations were conducted to study the effect of reservoir morphology (including real and simplified conical forms) on the water storage process at different reliability levels. The reservoirs were categorized as convex (60.0%), slightly convex (27.5%) or linear (12.5%). When the conical approximation was used instead of the real lake form, a trade-off occurred between reservoir yield and evaporation losses, with different trends for the convex,... Tipo: Info:eu-repo/semantics/article Palavras-chave: Evaporation losses; Hydrological modeling; Lake morphology; Reservoir yield; Semi-arid regions; Water availability. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000301113 Registros recuperados: 37 Primeira ... 1 2 ... Última

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