86 research outputs found
Análise das estimativas de precipitação: uma revisão
The precipitation is a meteorological variable of extreme importance. The variable is directly associated with the water supply reservoir, energy production and is responsible for flooding and soil erosion processes (SOUSA, 1998). In the agriculture, particularly, the knowledge of the rainfall regime stands out as a analysis tool and decision-making. Pluviograph and pluviometers are used to quantify rainfall. Through these two instruments it is possible to measure the rainfall amount and intensity. Therefore, with this data it is possible to local forecasting model and analysis systems. Thus, the accurate knowledge of precipitation time series is an essential tool future behavior modeling. In this work, a review of the main sensors employed to measure precipitation and the practical difficulties encountered by researchers when using rainfall data and sensor calibration. For this, a research in the Google academic was filtering the works associated with the subject. The results allowed to conclude that any rain gauge can be used, provided that it is properly calibrated.A precipitação é uma variável meteorológica de extrema importância. Esta variável está diretamente associada ao abastecimento de reservatórios de água, à produção de energia e é responsável pelas inundações e pelos processos erosivos do solo. Na agricultura, em especial, o conhecimento do regime de chuva se destaca como ferramenta de análise e tomada de decisões em relação ao manejo da cultura escolhida a partir do planejamento agrícola. Para quantificar as chuvas empregam-se pluviógrafos e pluviômetros. Através destes dois instrumentos é possível medir a quantidade e intensidade das chuvas. Sendo então possível modelar sistemas locais de previsão e análise. Assim, o conhecimento preciso das séries temporais de precipitação é um instrumento essencial para modelar comportamentos futuros. Desta forma, neste trabalho, foi realizada uma revisão dos principais dispositivos utilizados para medir a precipitação e as principais dificuldades encontradas pelos pesquisadores ao utilizar os dados de chuva e a calibração dos sensores. Para isso, realizou-se uma pesquisa no Google acadêmico filtrando os trabalhos associados ao tema. Os resultados permitiram concluir que qualquer pluviômetro pode ser empregado, desde que devidamente calibrado
MICORRIZAS ARBUSCULARES E FOSFATO NO DESENVOLVIMENTO DE MUDAS DE CEDRO-AUSTRALIANO
The Australian red cedar (Toona ciliata M. Roem var. Australis) is a species that has shown potential for forest use in Brazil. Thus, the objective of this study was to test the Australian red cedar seedlings response to inoculation with arbuscular mycorrhizal fungi (AMF) in different doses of P. The experiment was conducted in a Completely Randomized Design (CRD) in factorial 8 x 2, with five repetitions. The treatments consisted in inoculation of seven species of AMF: Rhizophagus clarus, Claroideoglomus etunicatum, Racocetra gregaria, Acaulospora colombiana, Acaulospora morrowiae, Gigaspora margarita and Dentiscutata heterogama, besides a treatment without inoculation; being subjected to two doses of phosphate 25 and 250 mg dm-3 and that levels were equivalent to 10.7 and 41.3 mg dm3, respectively, extracted by Mehlich-1. It was evaluated the percentage of colonization, sporulation, height, diameter, shoot dry matter and accumulation of nutrients, 150 days after transplanting. There were differences depending on the levels of P and isolated variables evaluated. At the lowest dose, the isolated Claroideoglomus etunicatum and Acaulospora colombiana benefit the growth and nutrient absorption, while at the highest dose, Acaulospora morrowiae showed to be more promising for the growth of plants.O cedro-australiano (Toona ciliata M. Roem var. australis) é uma espécie que tem apresentado potencial de utilização florestal no Brasil. Deste modo, o objetivo deste trabalho foi determinar a resposta de mudas de cedro-australiano à inoculação com fungos micorrízicos arbusculares (FMA) em diferentes doses de fósforo (P). O experimento foi conduzido em delineamento inteiramente casualizado em esquema fatorial 8 x 2, com cinco repetições. Os tratamentos consistiram na inoculação de sete espécies de FMA: Rhizophagus clarus, Claroideoglomus etunicatum, Racocetra gregaria, Acaulospora colombiana, Acaulospora morrowiae, Gigaspora margarita e Dentiscutata heterogama, além de um tratamento sem inoculação; sendo submetidos a duas doses de fosfato, 25 e 250 mg dm-3 que equivaleram a teores de 10,7 e 41,3 mg dm-3 P no solo, respectivamente. Avaliou-se a porcentagem de colonização micorrízica, esporulação, altura, diâmetro, matéria seca da parte aérea e acúmulo de nutrientes, 150 dias após o transplantio. Houve diferença em função das doses de P e dos isolados nas variáveis avaliadas. Os isolados Claroideoglomus etunicatum e Acaulospora colombiana beneficiaram o crescimento e a absorção de nutrientes do cedro-australiano em baixa disponibilidade de P, enquanto que Acaulospora morrowiae se mostrou mais promissor em solos com maior disponibilidade desse nutriente. Esses isolados proporcionam elevada colonização micorrízica no cedro, favorecendo a produção de mudas de qualidade com vistas ao estabelecimento e produtividade de plantios comerciais
MICORRIZAS ARBUSCULARES E FOSFATO NO DESENVOLVIMENTO DE MUDAS DE CEDRO-AUSTRALIANO
The Australian red cedar ( Toona ciliata M. Roem var. Australis) is a species that has shown potential for forest use in Brazil. Thus, the objective of this study was to test the Australian red cedar seedlings response to inoculation with arbuscular mycorrhizal fungi (AMF) in different doses of P. The experiment was conducted in a Completely Randomized Design (CRD) in factorial 8 x 2, with five repetitions. The treatments consisted in inoculation of seven species of AMF: Rhizophagus clarus , Claroideoglomus etunicatum , Racocetra gregaria , Acaulospora colombiana , Acaulospora morrowiae , Gigaspora margarita and Dentiscutata heterogama , besides a treatment without inoculation; being subjected to two doses of phosphate 25 and 250 mg dm -3 and that levels were equivalent to 10.7 and 41.3 mg dm -3 , respectively. It was evaluated the percentage of colonization, sporulation, height, diameter, shoot dry matter and accumulation of nutrients, 150 days after transplanting. There were differences depending on the levels of P and isolated variables evaluated. At the lowest dose, the isolated Claroideoglomus etunicatum and Acaulospora colombiana benefit the growth and nutrient absorption, while at the highest dose, Acaulospora morrowiae showed to be more promising for the growth of plants. These isolates provided high mycorrhizal colonization in the red cedar, favoring the production of quality seedlings, aiming the establishment and productivity of commercial plantations
New rhizobia strains isolated from the Amazon region fix atmospheric nitrogen in symbiosis with cowpea and increase its yield
Studies in the Amazon indicate a wide diversity of rhizobia with the ability for biological nitrogen fixation (BNF), which could expand the number of strains approved for cowpea. Thus, the aim of this field study was to evaluate the agronomic performance in cowpea of the several strains isolated from the soils of the Brazilian states Acre and Rondônia, and to compare them withstrains approved by the Ministry of Agriculture (MAPA) and withnon-inoculated controls (without and with mineral nitrogen fertilizer). The inoculants performed well. Though less effective than the other strains, the UFLA 03-36 strain also was prominent with respect to grain yield. Because of the positive response of the UFLA 03-129 strain, which led to yield increases greater than the obtained from the control without inoculation plus mineral-N, it can be recommended as an inoculum for cowpea. Further investigations should be carried out to obtain MAPA’s approval for their use. Other experiments involving this strain and several cultivars are being carried out on other types of soil and environmental conditions of the state of Minas Gerais
Atributos químicos de Latossolo após sucessivas aplicações de composto orgânico de dejeto líquido de suínos
Resumo: O objetivo deste trabalho foi determinar as alterações em atributos químicos de um Latossolo Vermelho após aplicações sucessivas de composto orgânico de dejeto líquido de suínos com maravalha, em sistema plantio direto. O experimento foi conduzido em Chapecó, SC, em Latossolo Vermelho, de setembro de 2005 a agosto de 2011. Foram aplicadas anualmente as doses de 0, 2, 4, 8 e 16 Mg ha-1 de composto de dejeto líquido de suínos com maravalha, além de um tratamento com adubação mineral (NPK). Após seis aplicações, coletaram-se amostras de solo nas camadas de 0-4, 4-8, 8-12, 12-16, 16-20, 20-40 e 40-60 cm e avaliaram-se os atributos químicos. As maiores doses do composto orgânico incrementaram o pH do solo e reduziram a acidez potencial. As aplicações de composto orgânico derivado de dejeto de suínos e maravalha promoveram alterações nos atributos químicos do Latossolo Vermelho avaliado, especialmente nas camadas superficiais do solo, com maior ênfase para aumento do pH do solo e dos teores de P, K, Cu e Zn. A utilização de 4 Mg ha-1 do composto mantém os atributos químicos do solo semelhantes aos do tratamento NPK, que seguiu recomendação oficial para os estados do Rio Grande do Sul e de Santa Catarina, além de manter os teores de P nas camadas superficiais dentro do limite crítico ambiental para solos com altos teores de argila
Atributos químicos de Latossolo após sucessivas aplicações de composto orgânico de dejeto líquido de suínos
The objective of this work was to determine changes in the chemical attributes of an Oxisol after successive applications of organic compounds with pig slurry and wood shavings, under a no‑tillage system. The experiment was conducted in the municipality of Chapecó, in the state of Santa Catarina, Brazil, in an Oxisol, from September 2005 to August 2011. The doses of 0, 2, 4, 8, and 16 Mg ha-1 compound with pig slurry and shavings were applied annually, as well as a treatment with mineral fertilizer (NPK). After six applications, soil was collected at the 0–4, 4–8, 8–12, 12–16, 16–20, 20–40, and 40–60‑cm layers and the chemical attributes were evaluated. The highest doses of the organic compound increased soil pH and reduced potential acidity. The applications of the organic compound derived from swine manure and wood shavings promoted changes in the chemical attributes of the evaluated Oxisol, especially in the upper soil layers, with greater emphasis on increased soil pH and P, K, Cu, and Zn contents. The use of 4 Mg ha-1 of the compound maintains the soil chemical attributes similar to those of the NPK treatment, which followed official recommendation for the states of Rio Grande do Sul and Santa Catarina, besides keeping the P content in the surface layers within the environmental critical limit for soils with high clay content.O objetivo deste trabalho foi determinar as alterações em atributos químicos de um Latossolo Vermelho após aplicações sucessivas de composto orgânico de dejeto líquido de suínos com maravalha, em sistema plantio direto. O experimento foi conduzido em Chapecó, SC, em Latossolo Vermelho, de setembro de 2005 a agosto de 2011. Foram aplicadas anualmente as doses de 0, 2, 4, 8 e 16 Mg ha-1 de composto de dejeto líquido de suínos com maravalha, além de um tratamento com adubação mineral (NPK). Após seis aplicações, coletaram-se amostras de solo nas camadas de 0–4, 4–8, 8–12, 12–16, 16–20, 20–40 e 40–60 cm e avaliaram-se os atributos químicos. As maiores doses do composto orgânico incrementaram o pH do solo e reduziram a acidez potencial. As aplicações de composto orgânico derivado de dejeto de suínos e maravalha promoveram alterações nos atributos químicos do Latossolo Vermelho avaliado, especialmente nas camadas superficiais do solo, com maior ênfase para aumento do pH do solo e dos teores de P, K, Cu e Zn. A utilização de 4 Mg ha-1 do composto mantém os atributos químicos do solo semelhantes aos do tratamento NPK, que seguiu recomendação oficial para os estados do Rio Grande do Sul e de Santa Catarina, além de manter os teores de P nas camadas superficiais dentro do limite crítico ambiental para solos com altos teores de argila
Rhizophagus Clarus and Phosphorus in Crotalaria juncea: growth, glomalin content and acid phosphatase activity in a copper-contaminated soil
Crotalaria juncea is used as plant cover in grape vineyards in Brazil, which usually present soils with high copper (Cu) levels due to the application of Cu-based phyto-sanitary products. Under this condition an increase growth and cover of C. juncea is needed to improve the phytoremediation processes in those soils. Some alternatives to achieve this condition is the inoculation with arbuscular mycorrhizal fungi (AMF), which has demonstrated an important increase of plant growth in Cu-contaminated soils at different soil P levels. The aims of this study were to evaluate the effect of AMF inoculation in soils with high Cu contents on the growth of C. juncea, the acid phosphatase (APase) enzyme activity in plants and soil, and the presence of glomalin under different P supply conditions, as a basis to identify if there is a synergistic interaction between AMF inoculation and P supply on soils with high Cu levels. The experiment was carried under greenhouse conditions in a factorial 3 × 2 design (natural P content, addition of 40 and 100 mg kg-1 P, with and without the inoculation of the AMF Rhizophagus clarus with three replicates) in a soil with high Cu content (60 mg kg-1). The addition of 40 and 100 mg kg-1 P favored plant growth both in the presence and in the absence of AMF. However, when plants were grown in soil with a natural P level, the inoculation with AMF increased by 116 % the shoot biomass, compared to the non-inoculated treatment. Our results showed that the combination of P supply and R. clarus inoculation could be an adequate strategy to reduce Cu phytotoxicity in C. juncea, as it increases plant biomass and modify the APase enzyme activity in the soil and plant. Additionally, glomalin produced by the AMF and accumulated in the soil can decrease the availability of Cu to the plants by means of sequestration beyond the root surface, with a consequent plant protective effect
A ten-year retrospective study of the clinical, sociodemographic, and survival characteristics of patients with oral and pharyngeal squamous cell carcinomas/ Estudo retrospectivo de dez anos das características clínicas, sociodemográficas e de sobrevida de pacientes com carcinomas epidermóides orais e faríngeos
Objective: This study evaluated the epidemiological profile of patients diagnosed with squamous cell carcinoma, as well compared oral and pharyngeal lesions regarding the survival of these patients. Material and Methods: Convenience sampling was employed to select the participants, who had their medical records of the period 200-2009 investigated. Sociodemographic and clinical-pathological data were collected and correlated with site of the lesion, TMN classification, of the tumor, and survival of the patients. Fisher’s and Chi-square tests, Kaplan-Meir curve associated with the Long Rank Mantel-Cox test, and Cox’s regression for survival analysis were performed to evaluate the results. Results: Sixty-year-old illiterate females presented higher prevalence of oral cancer with a more severe lymphonodular infiltration, worse tumor staging, and chemo and radiotherapy treatment. Meanwhile, sixty-year-old illiterate males presented higher prevalence of pharyngeal cancer, lower rates of lymphonodular infiltration, and chirurgical treatment. The survival of the patients with oral cancer was correlated with the lymphonodular infiltration level, while for patients with pharyngeal cancer the survival was correlated with chirurgical treatment. Thus, head and neck cancer are still diagnosed belatedly, mainly when it affects the pharynx.Conclusion: Therefore, preventive and educative strategies, as well as amplification of access to health care should be considered targets for achieving reduction in the mortality rates of populations with oropharyngeal cancer
Eficiência simbiótica de estirpes de Cupriavidus necator tolerantes a zinco, cádmio, cobre e chumbo
The objective of this work was to evaluate the tolerance of Cupriavidus necator strains to zinc, cadmium, copper and lead, as well as to determine the symbiotic efficiency of the most tolerant ones in legume species suited for use in revegetation. Tolerance was evaluated in LB medium supplemented with 2.5, 5.0, 7.5, 10, 12.5 and 15 mmol L‑1 of ZnSO4.7H2O, CdSO4.8H2O, CuSO4.5H2O and PbCl2, respectively, in comparison to a control without metal. The symbiotic efficiency of the four C. necator most metal-tolerant strains (UFLA02‑71, UFLA02‑73, UFLA01‑659 and UFLA01‑663) was determined, and these strains were inoculated in the species: Leucaena leucocephala, Enterolobium contortisiliquum, Acacia mangium, Mimosa caesalpiniifolia, M. pudica, M. pigra and M. acutistipula. Leucaena leucocephala, M. pudica and M. caesalpiniifolia and the strains UFLA02‑71 and UFLA01‑659, which presented the high symbiotic efficiency, were evaluatedin pots with soil. UFLA02‑71 provided increments of 870% in shoot dry matter of M. caesalpiniifolia, and UFLA01‑659 provided 885% in M. pudica and 924% in L. leucocephala. These strains should be assessed for potential use in programs to restore degraded areas, since they showed high efficiency in nitrogen fixation and were competitive with indigenous rhizobia populations, besides being highly tolerant to heavy metals.O objetivo deste trabalho foi avaliar a tolerância de estirpes de Cupriavidus necator a zinco, cádmio, cobre e chumbo, além de determinar a eficiência simbiótica das estirpes mais tolerantes em associação a espécies leguminosas com potencial para revegetação. A tolerância foi testada em meio LB, suplementado com 2,5; 5,0; 7,5; 10; 12,5 e 15 mmol L‑1 de ZnSO4.7H2O, CdSO4.8H2O, CuSO4.5H2O e PbCl2, respectivamente, em comparação ao controle sem adição de metal. Determinou-se a eficiência simbiótica das quatro estirpes de C. necator mais tolerantes aos metais avaliados (UFLA02‑71, UFLA02‑73, UFLA01‑659 e UFLA01‑663), as quais foram inoculadas nas espécies: Leucaena leucocephala, Enterolobium contortisiliquum, Acacia mangium, Mimosa caesalpiniifolia, M. pudica, M. pigra e M. acutistipula. Em vasos com solos, avaliaramse L. leucocephala, M. pudica e M. caesalpiniifolia e as estirpes UFLA01‑659 e UFLA02‑71, selecionadas na avaliação de eficiência simbiótica. A estirpe UFLA02‑71 proporcionou incrementos de matéria seca da parte aérea de 870% em M. caesalpiniifolia, enquanto que UFLA01‑659 proporcionou 885% em M. pudica e 924% em L. leucocephala. As estirpes UFLA01‑659 e UFLA02‑71, além da alta tolerância a metais pesados, apresentaram eficiência em fixar nitrogênio, em simbiose com essas leguminosas, em solos com rizóbios nativos capazes de nodulá‑las, e devem ser avaliadas quanto ao seu potencial de utilização em programas de recuperação de áreas degradadas
Desenvolvimento de um sistema para recomendação de calagem e adubação para as culturas de grãos
The recommendations of liming and fertilization for the different crops in the main producing regions of the country are based on the knowledge generated by researchers in the area of soil science. Interpretation tables for nutrient contents in the soil and tables with the amount of nitrogen, phosphorus and potassium were elaborated for the different manuals published in some states / regions. Under the name of AGROFERT, a WEB system was created that aims to integrate the information of the correction and fertilizer recommendation systems for the states of Rio Grande do Sul / Santa Catarina and Paraná for the main grain crops and to evaluate the evolution of the characteristics of the soil. The system has a consistent scientific basis, allowing for more comprehensive recommendations that can be continually improved. To date, different existing computerized recommendation systems are specific to a single state / region and provide simpler information. The Agrofert system saves time, since its use does not require calculating, correcting and writing recommendations by the traditional method (Manual)As recomendações de calagem e adubação para as diferentes culturas nas principais regiões produtoras do País fundamentam-se no conhecimento gerado por pesquisadores da área de ciências do solo. Tabelas de interpretação para os teores de nutrientes no solo e tabelas com as quantidade de nitrogênio, fósforo e potássio foram elaboradas para os diferentes manuais publicados em alguns estados/regiões. Sob a designação de AGROFERT, foi criado um sistema WEB que tem como objetivo integrar as informações dos sistemas de recomendação de corretivos e fertilizantes para os estados do Rio Grande do Sul/Santa Catariana e Paraná para as principais culturas de grãos e avaliar as evolução das características químicas do solo. O sistema apresenta uma base científica consistente, permitindo recomendações mais abrangentes e passíveis de contínuo aperfeiçoamento. Até o momento os diferentes sistemas de recomendação informatizados existentes são específicos para um único estado/região e trazem informações mais simplórias. O sistema Agrofert possibilita uma economia de tempo, pois seu uso dispensa calcular, corrigir e redigir recomendações pelo método tradicional (Manual)
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