Soil chemical properties changes by application of steel basic slag

A fabricação de aço está expandindo sua produção, o que vem aumentando a quantidade de resíduos sólidos gerados. As escórias básicas de aciaria apresentam características de corretivo da acidez do solo e fonte de nutrientes para as plantas, porém apresentam alguns metais pesados em sua constituição. O presente trabalho teve como objetivo avaliar o efeito da aplicação de escória de siderurgia na correção da acidez do solo e no aporte de metais pesados, como manganês (Mn), cobre (Cu), zinzo (Zn), cádmio (Cd), cromo (Cr) e níquel (Ni). O estudo foi conduzido em amostras de um Argissolo Vermelho Distrófico típico, dispostas em colunas e mantidas a céu aberto, em delineamento experimental de blocos casualizados, com quatro repetições. Os tratamentos consistiram em doses diferentes de escória de siderurgia com diferentes granulometrias, incluindo tratamentos com solo sob condição natural (controle) e corrigido (carbonato de cálcio e magnésio e adubação com nitrogênio, fósforo e potássio). Aos 12, 18 e 24 meses após a aplicação dos tratamentos foram coletadas amostras de solo das colunas para avaliação da reatividade da escória. A escória básica de aciaria finamente moída teve efeito similar ao carbonato na correção do pH do solo, no aumento da CTC efetiva e da saturação de bases. Partículas com diâmetro até 15 mm também foram efetivas para aumentar os valores desses atributos. As maiores doses de escória aumentaram os teores de Mn, Cr e Ni no solo em relação ao controle. Os resultados obtidos neste estudo, demonstram que a escória de siderurgia tem potencial para a utilização na correção do pH do solo.As the majority of industrial processes, siderurgy activities generate large amounts of residues. The siderurgic slags, byproducts of steel production have chemical characteristics that indicate their possible use in agriculture, as liming materials and sources of some plant nutrients. However, they may enclose undesired components, like heavy metals, which may result in situations of environmental hazard. In order to evaluate the effect on soil chemical properties and heavy metals accumulation in the soil by the application of steel basic slag, an experiment was carried out in soil columns (Typic Paleudult; 10 dm3/column soil volume), under natural rainfall conditions, in a completely randomized design with four replications. Soil treatments based on the liming rate do achieve pH 6,5 by the SMP method were: T1) Control; T2) CaCO3+MgCO3 (neutralizing value - PN 100%); T3) Treat. 2 + NPK fertilizers; T4) Slag - 1 x rate (particles < 0,149 mm e PN 60%); T5) Treat. 4 + NPK; T6) Slag - 2 x rate (1/3 particles < 0,149 mm e 2/3 particles 0,149 – 0,5 mm) + NPK; T7) Treat. 4 + N fertilizer; T8) Slag - 5 x rate (particles 0,5 – 2,0 mm) + Treat. 3; T9) Slag - 10 x rate (particles 2,0 – 15,0 mm) + Treat. 3. At equivalent rates both slag and carbonate increased similarly the values of pH, effective CEC and bases saturation in the soil. These attributes were higher for the treatments with slag at higher rates and larger particle size denoting the reactivity of the coarse factions. Among the analyzed metals, only Mn, Cr and Ni at higher slag rates (2, 5 and 10 x) increased in the soil to values significantly higher than the control and carbonate treatments. The results show that the used scoria is efficient as liming material and that it is not expected to provide excessive heavy metals accumulation when applied at rates to rise pH value up to 6,5 in soils with similar characteristics to that of this study. In summary, the slag exhibited a high potential for Ph corrections in soil

Fatty acid profile and meat quality of young bulls fed ground soybean or ground cottonseed and vitamin E

The objective of this study was to evaluate the fatty acid profile and qualitative characteristics of meat from feedlot young bulls fed ground soybean or ground cottonseed, with or without supplementation of vitamin E. A total of 40 Red Norte young bulls, with an initial average age of 20 months, and an initial average BW of 339 +/- 15 kg, were allotted in a completely randomized design using a 2 x 2 factorial arrangement, with two oilseeds, and daily supplementation or not of 2500 IU of vitamin E. The experimental period was for 84 days, which was preceded by an adaptation period of 28 days. The treatments were ground soybean (SB), ground soybean plus vitamin E (SBE), ground cottonseed (CS) and ground cottonseed plus vitamin E (CSE). The percentage of cottonseed and soybean in the diets (dry matter basis) was 24% and 20%, respectively. Diets were isonitrogenous (13% CP) and presented similar amount of ether extract (6.5%). The animals were slaughtered at average live weight of 464 +/- 15 kg, and samples were taken from the longissimus dorsi muscle for the measurement of fatty acid concentration and the evaluation of lipid oxidation and color of the beef. Before fatty acid extraction, muscle tissue and subcutaneous fat of the longissimus dorsi were separated to analyze fatty acid profile in both tissues. Supplementation of vitamin E did not affect fatty acid concentration, lipid oxidation and color (P &gt; 0.05). Subcutaneous fat from animals fed CS diet had greater C12: 0, C16: 0 and C18: 0 contents (P &lt; 0.03). In addition, CS diets reduced the C18: 1 and C18: 2 cis-9, trans-11 contents in subcutaneous fat (P &lt; 0.05). The muscle from animals fed CS tended to higher C16: 0 and C18: 0 contents (P &lt; 0.11), and decreased C18: 1, C18: 2 cis-9, trans-11 and C18: 3 contents (P &lt; 0.05) compared with SB. The Delta(9)-desaturase index was greater in muscle from animals fed SB (P &lt; 0.01). At 42 days of age, meat from cattle fed SB had a greater lipid oxidation rate (P &lt; 0.05). Meat from animals fed SB diets had less lightness and redness indices than meat from animals fed CS diets after 14 days of age. In conclusion, the addition of ground cottonseed in the finishing diets did increase the saturated fatty acid content of the longissimus dorsi. However, animals fed cottonseed exhibited greater lightness and redness of beef. In this study, the addition of vitamin E did not affect qualitative characteristics of meat

Conciliar o útil ao agradável e fazer ciência: Jardim Botânico do Rio de Janeiro - 1808 a 1860 Joining pleasure and work in the making science: the Jardim Botânico do Rio de Janeiro - 1808 to 1860

Embora esteja às vésperas de completar duzentos anos, a trajetória do Jardim Botânico do Rio de Janeiro ainda carece de estudo sistematizado. O artigo busca compreender as questões que ocasionaram o desinteresse por esse estabelecimento científico nas pesquisas da história das ciências e das instituições, acarretando a permanência do que consta em memória elaborada pelo seu diretor João Barbosa Rodrigues, por ocasião do centenário da instituição. Analisa as principais questões relacionadas à sua história desde a criação em 1808, até sua incorporação pelo Imperial Instituto Fluminense de Agricultura, em 1861, com o objetivo de colaborar para as discussões acerca da história das instituições e das ciências naturais, no período em foco.<br>Jardim Botânico do Rio de Janeiro played an important role in the first half of the nineteenth century. Although the park will soon celebrate its two-hundredth anniversary, no systematized study of it has ever been undertaken. With the intent of contributing to discussions on the history of institutions and the natural sciences during the period in question, the article seeks to uncover what has lain behind this disinterest in the Garden on the part of researchers from the history of the sciences and history of institutions. The article also analyzes major issues in the history of the Garden from its creation in 1808 until becoming part of the Imperial Instituto Fluminense de Agricultura in 1861