This study attempts to model the effects of meteorological factors in COVID-19 spread in Brazil • High mean temperatures influenced the COVID-19 transmission rate • Intermediate relative humidity influenced the COVID-19 transmission rate • Correlation of meteorological conditions with COVID-19 spread is presented for five Brazilian cities • This study aims to support decisionmakers to avoid deaths by the collapse of health-care systems

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-Anthropic action, such as the soil use and management systems, promote changes in the soil structure. These changes might hamper the development of plants in soil management practices that involve its mobilization, and the negative effects might be increased due to intensive use. The aim of this study was to evaluate the physico-hydrical properties of a Haplohumox in integrated production systems under different soil managements. The soil superficial (0.0-0.10 m) and subsuperficial (0.10-0.20 m) layers were evaluated in the different systems: conventional tillage (CT), minimum tillage (MT), no-tillage (NT) and chiseled no-tillage (CNT), taking into consideration the annual ryegrass cropped for different uses [cover crop (C), grazing (G) and silage (S)] during the winter. Soil bulk density (Db), total porosity (TP), macro (Ma) and microporosity (Mi), water retention curves (SWRC) and water retention due to pore size (r) were determined. The annual ryegrass used as C produced lower Db and Mi and higher TP and Ma in CT, MT and CNT systems. No difference was verified between G and S in any of the management systems or soil layers. The superficial layer SWRC presented similar behavior regarding CT, MT and CNT. Under NT, C resulted in higher water retention. However, G and S provided higher water retention due to the pore size in this system. Key words: Haplohumox. No-tillage. Soil physical quality. Crop-livestock integration. Agriculture sustainability.RESUMO -As ações antrópicas, como os sistemas de uso e manejo do solo, promovem alterações em sua estrutura. Estas alterações podem ser restritivas ao desenvolvimento das plantas em manejos do solo que envolva sua mobilização, tendo seus efeitos negativos potencializados pela maior intensificação de uso. O objetivo deste trabalho foi avaliar os atributos físico-hídricos de um Latossolo Bruno argiloso em sistemas integrados de produção sob distintos manejos de solo. Para isso avaliou-se a camada superficial (0.0-0.10 m) e subsuperficial (0.10-0.20 m) do solo nos sistemas de cultivo convencional (CT), mínimo (MT), plantio direto (NT) e plantio direto escarificado (CNT) sob diferentes usos da cultura do azevém [planta de cobertura (C), pastejo (G) e silagem (S)]. Determinou-se a densidade (Db), porosidade total (TP), macro (Ma) e microporosidade (Mi), as curvas de retenção de água (CRA) e a retenção de água em função do raio de poro (r). O uso do azevém como C proporcionou menores Db e Mi e maiores TP e Ma nos sistemas CT, MT e CNT. Não foram verificadas diferenças entre G e S para todos os manejos, em ambas as camadas de solo. As CRA da camada superficial entre CT, MT e CNT apresentaram comportamento semelhante. No NT, C proporcionou uma maior retenção de água. Entretanto, G e S proporcionaram maior a retenção de água em função dos raios de poros no NT.Palavras-chave: Latossolo Bruno. Plantio direto. Qualidade física do solo. Integração lavoura-pecuária. Sustentabilidade agrícola.*Autor para correspondência 1 Recebido para publicação em 10/05/2014; aprovado em ...

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It is generally accepted that liming ameliorates soil acidity. However, the method of lime application is thought by many to influence its effectiveness in acid soils. In this study, we wanted to assess the degree of effectiveness of surface-applied lime and lime incorporated into the soil on soil structural attributes and water retention of a Dystrudept soil in the SE region of the State of Paran a, Brazil. Lime was added at the rate of 15 t/ha to soil through: (i) surface broadcasting, (ii) incorporation via ploughing and harrowing, (iii) incorporation via subsoiling and harrowing. A control treatment with zero lime application was included in the experiment. The addition of lime by surface broadcasting resulted in significant reductions in soil bulk density (BD) and macroporosity (Ma) and increases in total porosity (TP) and microporosity (Mi) of the top soil layer (0-0.10 m). The reverse was the case in the 0.10-to 0.20-m soil layer; where lime was incorporated via ploughing and harrowing, increases in BD and reductions in TP and Ma were observed. Addition of lime also significantly increased soil water retention, with maximum retention recorded from soil amended with surface broadcast lime. Changes in soil chemical attributes (increases in pH, Ca 2+ and Mg 2+ contents; reductions in potential acidity and Al 3+ content) were responsible for the changes observed in structural and physical attributes, and water retention. Bearing in mind the lower application costs, improvement in the soil chemical attributes for plant development and soil physical quality, surface broadcast lime can be considered a promising alternative for no-till farmers.

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