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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Perdas de nutrientes e matéria orgânica por erosão em entressulcos em argissolo com resíduos de cana-de-açúcar /

Romero, Nilton Carlos de Souza. January 2009 (has links)
Orientador: Marcílio Vieira Martins Filho / Banca: Jose Marques Junior / Banca: Zigomar Menezes de Souza / Resumo: As reduções das perdas de matéria orgânica e nutrientes por erosão hídrica do solo tornam-se fundamentais, no contexto atual de sistemas de produção sustentáveis, para o aumento do seqüestro de carbono no solo e, consequentemente, diminuir as emissões de gases que contribuem para o efeito estufa como o CO2. Deste modo, o objetivo do presente trabalho foi o de quantificar as concentrações de matéria orgânica (MO) e nutrientes (P, K, Ca e Mg) e, calcular, a taxa de enriquecimento desses elementos no sedimento erodido, em área cultivada com a cultura de cana-de-açúcar, em níveis de cobertura do solo de 0% (CS0), 50% (CS50) e 100% (CS100).As parcelas experimentais foram submetidas à ação de uma chuva simulada com intensidade de 60 mm h-1, durante 65 minutos. Foram feitas análises do sedimento erodido e determinouse, as taxas de enriquecimento do mesmo em MO e nutrientes, valores estes que tiveram as seguintes variações: MO (2,9 a 0,5), P (1,5 a 0,2), K (2,4 a 0,8), Ca (3,5 a 0,5), Mg (3,3 a 0,3) sendo cobertura do solo 0% a 100% respectivamente, mostrando que a cobertura do solo de 100% é eficiente, apresentando todos os valores da taxa de enriquecimento (ER) abaixo de 0,9 e com diferença significativa para com as outras coberturas, 0% e 50%, com exceção do potássio. A cobertura do solo de 100%, em relação a 0%, reduziu a concentração de MO, no sedimento erodido, em 81,9%, a concentração de fósforo em 84,2%, a de potássio em 66,7%, a de cálcio em 84,5%, e reduziu em 89,8% a de magnésio / Abstract: Reductions in losses of organic matter and nutrients by water erosion become crucial in the current context of sustainable production systems to increase carbon sequestration in soil and thus reduce greenhouse gas emissions that contribute to the greenhouse gases like CO2. Thus the present work had a goal to quantify the concentration of organic material (MO) and nutrients (P,K,Ca, and Mg) into a erosive sediments and also make an calculate according to increasing and enrichment soil's rates, if there are enrichment of MO and nutrients in a cultivated area of sugar-cane plantation provided with mechanical crop the next levels of soil's coverage, 0% (CS0), 50% (CS50) and 100% (CS100). The experimental pieces were submited into a simulated raining with intensity of 60 mm h-1, during 65 minutes. After that, the analysis of the sediments, determinated the following variation: MO (2.9 to 0.5), P (1.5 to 0.2), K (2.4 to 0.8), Ca (3.5 to 0.5), Mg (3.3 to 0.3), being the soil's coverage 0% (CS0) to 100% (CS100), showing that the soil's coverage of 100% was efficient, presenting all values of enrichment rates (ER) below 0.9 with significant difference comparing to the others coverage, 0% (CS0) and 50% (CS50), except for potassium. The soil's coverage of 100%, on soil's coverage of 0%, have reduced the concentration of MO, in the erosive sediments, in 81.9%, the concentration of phosphorus in 84.2%, the concentration of potassium in 66.7%, the concentration of calcium in 84.5%, And reduced in 89.8% the magnesium concentration / Mestre

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