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Registros recuperados: 147 | |
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GUIMARÃES FILHO, C.; LOPES, P. R. C.; SILVA, P. C. G. da. |
Em função da profunda diversidade de condições agroecológicas e sócioeconômicas que caracteriza a região semi-árida e da extrema complexidade que envolve a natureza dos fatores responsáveis pela condição de pobreza das comunidades que nela habitam, a concepção de um programa de convivência com a seca requer, antes de tudo, uma visão abrangente na definição do caminho a ser seguido. A sua execução, portanto, exigirá uma ampla ação cooperativa transdisciplinar e multiinstitucional. A base para o desenvolvimento econômico e social do Semi-Árido e, por conseguinte, o conviver com seca, não deve se limitar ao desenvolvimento da atividade agrícola. Este deve estar associado ao crescimento das atividades econômicas rurais (agrícolas e não agrícolas) que se... |
Tipo: Documentos (INFOTECA-E) |
Palavras-chave: Convivência com a seca; Semiárido; Desenvolvimento local; Espaço agronômico; Produção local; Seca; Resistência a Seca; Alimentação Na Seca; Recurso Natural; Desenvolvimento Sustentável; Projeto de Desenvolvimento; Desenvolvimento Socio-Econômico; Social environment; Rural development; Rural economics; Rural policy; Drought; Drought tolerance. |
Ano: 2003 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1093481 |
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GUEDES, F. L.; POMPEU, R. C. F. F.; BUENO, L. G.; SOUZA, H. A. de; ROGERIO, M. C. P.. |
Resumo - O presente trabalho objetivou verificar se a metodologia com a utilização de lâminas de irrigação com base na evapotranspiração diária para aplicação de estresse hídrico em genótipos de Urochloa mosambicensis consegue determinar até qual nível de estresse essa espécie suporta, em dois tipos de solos do semiárido, um de textura arenosa e outro de textura média. O experimento consistiu em um fatorial triplo 3x4x2 (3 genótipos de gramíneas - UmCO-1 (2), UmCO-4 (1), BRS Paiaguás, 4 lâminas de irrigação - 30%, 60%, 90% e 120% da evapotranspiração de referência (ET0) e dois tipos de textura de solo) em delineamento inteiramente casualizado com 4 repetições. A metodologia com base na evapotranspiração de referência (ET0) em U. mosambicensis foi eficiente... |
Tipo: Folhetos |
Palavras-chave: Semiárido; Período seco; Dry period; Brasil; Gramínea Forrageira; Irrigação; Capim Urochloa; Forage grasses; Dry season; Irrigation; Drought; Semiarid soils; Brazil. |
Ano: 2022 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1148930 |
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SILVA, J. P. da; MEIRELES, E. J. L.; CAMARGO, M. B. P. de; PANTANO, A. P.; ROMANI, L. A. S.. |
Este manual tem por objetivo apresentar, de forma rápida e prática, a ferramenta para cálculo o balanço hídrico pelo método de Thornthwaite e Mather (1955), otimizando seu uso e aquisição de resultados pelo público interessado, contribuindo, assim, para o planejamento e tomadas de decisão das atividades agropecuárias e de pesquisas. |
Tipo: Documentos (INFOTECA-E) |
Palavras-chave: Evapotranspiração potencial; Excedente hídrico; Balanço hídrico; Deficiência hídrica; Evapotranspiração; Water balance; Evapotranspiration; Drought. |
Ano: 2016 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1065245 |
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Aguilos, Maricar; Stahl, Clement; Burban, Benoit; Herault, Bruno; Courtois, Elodie; Coste, Sabrina; Wagner, Fabien; Ziegler, Camille; Takagi, Kentaro; Bonal, Damien. |
Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern... |
Tipo: Text |
Palavras-chave: Tropical rainforest; Evapotranspiration; Water use efficiency; Drought; Radiation. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00484/59572/62542.pdf |
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Descroix, Luc; Sané, Yancouba; Thior, Mamadou; Manga, Sylvie-paméla; Ba, Boubacar Demba; Mingou, Joseph; Mendy, Victor; Coly, Saloum; Dièye, Arame; Badiane, Alexandre; Senghor, Marie-jeanne; Diedhiou, Ange-bouramanding; Sow, Djiby; Bouaita, Yasmin; Soumaré, Safietou; Diop, Awa; Faty, Bakary; Sow, Bamol Ali; Machu, Eric; Montoroi, Jean-pierre; Andrieu, Julien; Vandervaere, Jean-pierre. |
In West Africa, as in many other estuaries, enormous volumes of marine water are entering the continent. Fresh water discharge is very low, and it is commonly strongly linked to rainfall level. Some of these estuaries are inverse estuaries. During the Great Sahelian Drought (1968–1993), their hyperhaline feature was exacerbated. This paper aims to describe the evolution of the two main West African inverse estuaries, those of the Saloum River and the Casamance River, since the end of the drought. Water salinity measurements were carried out over three to five years according to the sites in order to document this evolution and to compare data with the historical ones collected during the long dry period at the end of 20th century. The results show that in... |
Tipo: Text |
Palavras-chave: Water salinity; Inverse estuaries; West Africa; Drought; Mangrove. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72434/71381.pdf |
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Bréchet, Laëtitia; Courtois, Elodie A.; Saint-germain, Thomas; Janssens, Ivan A.; Asensio, Dolores; Ramirez-rojas, Irene; Soong, Jennifer L.; Van Langenhove, Leandro; Verbruggen, Erik; Stahl, Clément. |
Tropical soils are a major contributor to the balance of greenhouse gas (GHG) fluxes in the atmosphere. Models of tropical GHG fluxes predict that both the frequency of drought events and changes in atmospheric deposition of nitrogen (N) will significantly affect dynamics of soil carbon dioxide (CO2) and methane (CH4) production and consumption. In this study, we examined the combined effect of a reduction in precipitation and an increase in nutrient availability on soil CO2 and CH4 fluxes in a primary French Guiana tropical forest. Drought conditions were simulated by intercepting precipitation falling through the forest canopy with tarpaulin roofs. Nutrient availability was manipulated through application of granular N and/or phosphorus (P) fertilizer to... |
Tipo: Text |
Palavras-chave: Carbon dioxide; Drought; Fertilization; Methane; Nitrogen; Phosphorus; Soil GHG fluxes; Tropical forest. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70694/68903.pdf |
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Teixeira,Gabriel E.; Bialetzki,Andréa; Soares,Bruno E.; Souza,Guilherme; Caramaschi,Érica P.. |
ABSTRACT The Paraíba do Sul River is affected by extensive water collection for supply, organic and industrial pollution, and dams. Nonetheless, the ichthyofauna maintains biodiversity and sustains artisanal fisheries. This study analyzes the composition, abundance and distribution of fish larvae, an important approach to determine the reproductive period and spawning sites. The sampling occurred from August 2011 through February 2013 in five sites at a transect between the banks on the lower reach of the Paraíba do Sul River. A total of 5,412 larvae belonging to 20 taxa was captured. The predominant order was Characiformes. Larvae of Prochilodus spp. and Leporinus spp. were the most abundant; larvae of Brycon insignis, an endangered species, were present.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Drought; Eggs and larvae; Migratory species; Reproductive period; Spawning area. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000500208 |
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Zanetti,Leonardo Valandro; Milanez,Camilla Rozindo Dias; Gama,Vinícius Novo; Aguilar,Marco Antonio Galeas; Souza,Carlos Alberto Spaggiari; Campostrini,Eliemar; Ferraz,Tiago Massi; Figueiredo,Fábio Afonso Mazzei Moura de Assis. |
Abstract: The objective of this work was to evaluate the physiological and anatomical traits of plants of a cacao (Theobroma cacao) clone in response to water deficit after leaf application of silicon. A randomized complete block design was used, with four replicates, in a 2x3 factorial arrangement of two water regimes (irrigated or nonirrigated) and three silicon concentrations (0.0, 1.5, and 3.0 mg mL-1) applied in wettable SiO2 powder. The plants were evaluated 20 days after the irrigation regimes were applied. The use of SiO2 increased the stability of cell membranes and the photochemical efficiency of the plants under water deficit. The 1.5 mg mL-1 concentration of SiO2 increased photosynthetic rate, water use efficiency, and carboxylation efficiency,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Theobroma cacao; Anatomy; Antioxidant enzymes; Drought; Photochemistry; SiO2. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000300215 |
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Carvalho,Luciana Marques de; Araújo,Stela Braga de; Carvalho,Hélio Wilson Lemos de; Carvalho,Claudio Guilherme Portela de. |
Abstract: The objective of this work was to evaluate the proline content of sunflower (Helianthus annuus) cultivars, in the conditions of natural water deficit in the Brazilian semiarid region. Thirteen cultivars were sown in experiments set in three sites in the Brazilian Northeast. Proline content was determined on leaves from plants at the R4-R5 stage. Significant differences among cultivars occurred only where water availability was lower. Proline averages ranged from 3.47 to 17.41 μg g-1. The sunflower cultivars BRS387, BRS323, and BRS324 showed the greatest proline contents with 54.74, 46.27, and 35.16 μg g-1, respectively. These are the cultivars that accumulate more proline under conditions of a severe water deficit. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Helianthus annuus; Drought; Water deficit. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000800970 |
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Souza,Leandro Vagno de; Miranda,Glauco Vieira; Galvão,João Carlos Cardoso; Guimarães,Lauro José Moreira; Santos,Izabel Cristina dos. |
The objectives of this work were to caracterize the tropical maize germplasm and to compare the combining abilities of maize grain yield under different levels of environmental stress. A diallel was performed among tropical maize cultivars with wide adaptability, whose hybrid combinations were evaluated in two sowing dates, in two years. The significance of the environmental effect emphasized the environmental contrasts. Based on grain yield, the environments were classified as favorable (8,331 kg ha-1), low stress (6,637 kg ha-1), high stress (5,495 kg ha-1), and intense stress (2,443 kg ha-1). None of the genetic effects were significant in favorable and intense stress environments, indicating that there was low germplasm variability under these... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Abiotic stress; Breeding; Diallel; Drought. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001000013 |
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Martini,Luiz Carlos Pittol. |
Abstract: The objective of this work was to perform a sensitivity analysis of the main input parameters required for the AquaCrop water balance model, using biomass and grain yield data of a rainfed-simulated corn crop, obtained along the climate data series of 1987-2016 in the South of Brazil. The levels of soil-water stress and the depths of maximum effective rooting were the input parameters that most affected the biomass and grain yields simulated by the model, followed by the crop coefficient, water-use efficiency, soil water storage capacity, and contribution of groundwater to water availability in the root zone. The parameters crop cycle duration, plant density, pattern of soil-water extraction, and field surface practices showed little or no impact... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calibration; Crop model; Drought; Simulation; Soil-water balance; Soil-water stress. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000800934 |
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Wild,Anna-Katharina; Marx,Michael Thomas; Eisenbeis,Gerhard. |
Micro, macro and mesofauna in the soil often respond to fluctuating environmental conditions, resulting in changes of abundance and community structure. Effects of changing soil parameters are normally determined with samples taken in the field and brought to the laboratory, i.e. where natural environmental conditions may not apply. We devised a method (STAFD - soil tubes for artificial flood and drought), which simulates the hydrological state of soil in situ using implanted cores. Control tubes were compared with treatment tubes in which floods of 15, 30, 60 and 90 days, and droughts of 60, 90 and 120 days were simulated in the field. Flooding and drought were found to reduce number of individuals in all soil faunal groups, but the response to drought... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Climate change; Drought; Flooding; Soil invertebrates; Soil tubes; STAFD method. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000800007 |
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Souza,Thiago Corrêa de; Magalhães,Paulo César; Castro,Evaristo Mauro de; Duarte,Vinícius Politi; Lavinsky,Alyne Oliveira. |
Abstract: The objective of this work was to characterize the morphoanatomy of roots and the yield traits of two corn hybrids contrasting for drought tolerance (DKB 390, tolerant; and BRS 1030, sensitive), at different stages of development. Water deficit was imposed for ten days, in a greenhouse, at three growth stages: V5, VT, and R3. These treatments were combined to generate cumulative stress during the plant cycle, as: V5VT, V5R3, VTR3, and V5VTR3. The following were analyzed: root anatomy; proportion of aerenchyma in the cortex; metaxylem number and diameter; phloem thickness; as well as morphological characteristics, such as root length, volume, and surface area, specific root length, length of fine roots, grain yield, and ear length and diameter.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Aerenchyma; Drought; Endoderm; Specific root length; WinRhizo.. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000400330 |
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Registros recuperados: 147 | |
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