Alfalfa cultivar Crioula (Medicago sativa cv. Crioula) is grown in South Brazil and only a few studies on the plants' boron requirement are available. A greenhouse experiment was carried out with alfalfa to measure boron acquisition, production and distribution in the plant; data on critical level and production potentials were recorded. Plants were grown in ground quartz added with 1 L of solution, with the following boron rates: 0, 0.0625, 0.125, 0.25, 0.50, 1.00, and 2.00 mg L -1 . Plants were harvested at 46 days of growth. Forage dry mass was increased by boron supply and dry matter accumulation was considerably low in control. Boron concentration in the leaves was higher than in the stems or roots. Boron utilization from the external solution reached 90% at 0.0625 mg L -1 and sharply decreased with further increasing boron rates. Boron concentration and content in the leaves and in plant tops were at maximum when applied boron was between 1.5 and 1.6 mg L -1 . Critical levels of boron in plant were 61 mg kg -1 in the leaves and 39 mg kg -1 in plant tops for this cultivar of alfalfa. Key words: Lucerne, Medicago sativa, plant nutrition, micronutrient, critical level NUTRIÇÃO EM BORO E PRODUÇÃO DE ALFAFA CULTIVAR CRIOULA EM FUNÇÃO DO SUPRIMENTO DE BORORESUMO: O cultivar Crioula de alfafa (Medicago sativa cv. Crioula) é utilizado no Sul do Brasil e existem poucos estudos referentes a sua exigência em boro. Foi conduzido um experimento com alfafa cultivada no inverno, com o objetivo de avaliar a quantidade de boro absorvido pelas plantas, o efeito de doses de boro na produção de massa seca, a distribuição do boro nas plantas e obter informações relacionadas à diagnose de boro nessa forrageira. As doses de 0; 0,0625; 0,125; 0,25; 0,50; 1,00 e 2,00 mg L -1 foram aplicadas no substrato, colocando-se 1 L de solução nutritiva em cada recipiente. As plantas foram cortadas aos 46 dias após o transplante. A massa seca da forrageira foi influenciada pelas doses de boro e foi insignificante quando a solução nutritiva apresentava a mais baixa concentração de boro. A concentração de boro nas folhas foi mais elevada que nas hastes e nas raízes. A utilização de boro da solução atingiu 90% na dose de 0,0625 mg L -1 e decresceu acentuadamente com o incremento das doses de boro. A concentração e o conteúdo de boro nas folhas e na parte aérea da planta foram mais elevados quando o boro se encontrava na solução nutritiva entre 1,5 e 1,6 mg L -1 . O nível crítico de boro foi de 61 mg kg -1 nas folhas e 39 mg kg -1 na planta para este cultivar de alfafa. Palavras-chave: Medicago sativa, nutrição de plantas, micronutriente, nível crítico

RESUMOEm condições controladas de temperatura, umidade e iluminação, 30 genótipos de Panicum maximum foram avaliados para a verificação de tolerância às doses de alumínio de 0, 12 e 24 mg L -1 em solução nutritiva. Os efeitos do alumínio na inibição do alongamento radicular e no índice de tolerância possibilitaram a estratificação dos genótipos em três categorias: tolerantes, intermediários e sensíveis. A maior parte dos genótipos apresentou de média a baixa tolerância ao alumínio, destacando-se, como os mais tolerantes, os genótipos K191, T95, T84, T91 e Centenário e, como os mais sensíveis, os genótipos Centauro, K68, K214 e T46.Termos de indexação: toxidez ao alumínio, gramínea forrageira, estresse mineral. SUMMARY: ALUMINUM TOLERANCE IN Panicum maximum

In the region of the Paraíba do Sul river valley in the State of São Paulo, Brazil, pasture areas have been replaced by eucalyptus plantations, which can modify the dynamics of water in the soils of the region. The objective of this work was to evaluate the behavior of water in a Red-Yellow Latosol in two vegetative coverings, a six-year-old eucalyptus plantation, and a native forest, in the process of regeneration which began twenty years ago. The study was developed in the Una River basin from June 2009 to April 2011. The soil water potential was measured by 96 sensors (Watermark ™) at the depths of 20, 60 and 120 cm. The Available Water Capacity (AWC) and weekly residual soil storage for each layer were calculated. It was observed that the three layers reacted to the processes of rainfall and evapotranspiration and that there was a difference between the storage of water in the soil in the eucalyptus and native forest areas. There was no water restriction in the studied period; however, the variations in native forest storage were smoother than the variations occurring for eucalyptus. In the mean of the whole period and for the three layers, the storage in the native forest and eucalyptus were 88% and 64% of Available Water Capacity (AWC = 183 mm), respectively. These results show the native forest water conservation capacity in watersheds. Palavras-chave: bacias hidrográficas, tensiômetro, uso da água, floresta.

RESUMOA ocorrência de chumbo (Pb) e zinco (Zn) foram determinadas em amostras de solo e de gramíneas coletadas em três pontos de um trecho de 143 km da rodovia Presidente Dutra, entre os estados de São Paulo e Rio de Janeiro, nas distâncias perpendiculares de 0-10 m, 10-20 m, 20-35 m e 35-50 m da margem da rodovia. As concentrações de Pb e de Zn foram maiores nas amostras mais próximas da rodovia, diminuindo com o aumento da distância da rodovia, tanto nas amostras de solo, quanto nas amostras de planta. Os coeficientes de correlação entre concentração do metal no solo e concentração do metal na planta foram positivos, tanto para Pb quanto para Zn. De modo geral, as concentrações de Pb encontradas nas amostras de solo foram inferiores ao valor de referência de qualidade estabelecido para os solos no estado de São Paulo. Já para o Zn, até 10 m de distância da margem da rodovia a concentração foi superior ao valor de referência.Palavras-chave: poluição do solo, metais pesados, contaminação ambiental. Occurrence of lead and zinc in soils and plants at the margins of a highway with heavy traffic ABSTRACTThe occurrences of lead (Pb) and zinc (Zn) were determined in soil and grasses collected at three points on stretch of 143 km of the Presidente Dutra highway between the states of São Paulo and Rio de Janeiro. The soil and plant samples were collected by sampling transections perpendicular to the highway at distances of 0, 10, 20, 35 and 50 m from the highway edge. Concentrations of Pb and Zn were higher in samples closest to the highway edge, decreasing with increasing distance from the road. There were positive correlation coefficients between the metal concentration in the soil and the metal concentration in the plant. Concentrations of Pb found in soil samples were below the reference value established for the soil quality in the state of São Paulo, while for Zn, up to 10 m away from the highway edge, the concentration was higher than the reference value.

BACKGROUND: Exposure to some air pollutants is associated with cardiovascular diseases. The objective of this study was to quantify the effect of exposure to fine particulate matter in hospitalizations due to ischemic heart disease and the costs to the healthcare system. DESIGN AND SETTING: Time-series ecological study conducted in Taubaté, Brazil. METHODS: Data on hospitalizations due to ischemic heart diseases (ICD I-20 to I-24) in the municipality of Taubaté (SP), Brazil, among adults of both sexes aged 40 years and over, from August 2011 to July 2012, were obtained from DATASUS. Fine particulate matter (PM 2.5) concentrations were estimated from a mathematical model. Poisson regression was used in statistical analyses to estimate the relative risks of exposure to PM 2.5 for both sexes and after stratification according to sex. The excess of hospitalizations and consequent excess expenditure for the healthcare system were calculated. RESULTS: There were 1040 admissions, among which 382 had ischemic heart diseases (257 males). The mean PM 2.5 concentration was 13.2 µg/m 3 (SD = 5.6). Significant effects from exposure were noted 4 and 5 days after exposure (lag 4 and lag 5) for both sexes and for male sex; for female sex, the effect was 2 days after exposure (lag 2). There were 59 excess hospitalizations for an increase in PM 2.5 concentration of 5 µg/m 3 and excess expenditure of US$ 150,000 for the National Health System. CONCLUSIONS: An excess of hospital admissions due to ischemic heart disease, with excess expenditure, was identified consequent to PM 2.5 exposure.