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Navegando Teses e Dissertações por Assunto "Acidity correction"

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    Disponibilidade hídrica no solo e intervalo após a calagem para implantação de gramíneas forrageiras
    (Universidade Federal de Mato Grosso, 2021-02-26) Gregório, Francisco Cidnei; Cabral, Carlos Eduardo Avelino; 019.717.471-06; http://lattes.cnpq.br/6739111102181898; Leão, André Gustavo; 290.547.528-58; http://lattes.cnpq.br/7286596323526732; Leão, André Gustavo; 290.547.528-58; http://lattes.cnpq.br/7286596323526732; Cabral, Carlos Eduardo Avelino; 019.717.471-06; http://lattes.cnpq.br/6739111102181898; Abreu, Joadil Gonçalves de; 830.338.746-49; http://lattes.cnpq.br/1410481664723748; Carvalho, Kassio dos Santos; 019.614.551-10; http://lattes.cnpq.br/6803860677169308
    In tropical conditions, the correction of soil acidity is an important step in the process of implanting forages, being essential for success in the pasture formation. However, the need for intervals between application of lime and sowing of more than 60 days occupy a considerable part of rainy season and can compromise the establishment pasture. Although it involves time, the reaction of the limestone in the soil is dependent on the soil water availability, and the faster the greater the presence of water interacting with the CaCO3 of the limestone. In this work, the objective was: (1) to verify if it is possible for acidity correction to occur in less than 60 days after the incorporation of limestone; (2) what soil water availability is necessary for acidity correction to occur in less than 60 days. For this, two experiments were carried out in a greenhouse in Rondonópolis-MT with a completely randomized design in a factorial scheme. In the first experiment, 8 treatments were evaluated, obtained from the combination of the number of times the soil was raised to the maximum water retention capacity (1, 2, 3 and 9 irrigations) and two expected base saturations (50 and 60 %). Dolomitic lime (calcium oxide: 31%, magnesium oxide: 21%, neutralizing power: 107%, RE: 80.4% and total relative neutralizing power: 86%) was used to raise base saturation. The pH and aluminum saturation of the soil, before liming, were 4.1 and 75%, respectively. Forty-five days after the incorporation of the lime, chemical analysis of the soil was carried out and sowing of the cultivar BRS RB331 Ipyporã (Brachiaria brizantha x Brachiaria ruziziensis). The soil pH (CaCl2) was raised to values above 5.0 in all treatments. Irrigations number did not affect the saturation of toxic aluminum in the soil, however, there was a reduction in aluminum saturation from 75.0 to 3.5%. Beside, irrigations number did not alter the development of the grass and a single irrigation, increasing the soil moisture for maximum water retention capacity, corrected the acidity of the soil and made it possible to reduce the interval between liming and sowing to 45 days. Second experiment was carried out with the cultivar Mombasa (Panicum maximum), in which 6 treatments were adopted in a 3x2 factorial scheme, constituted by the combination of three soil water availability (50, 75 and 100% of the maximum water retention capacity in the soil) and two lime reaction periods (30 and 60 days). Soil water availability changed the lime reaction time. Results of the soil analysis indicated that thirty days after liming, with a precipitation capable of raising the soil moisture to 50% of the maximum water holding capacity, chemical changes occurred in the soil, so that the main one was the absence of toxic aluminum. However, for implantation of the pasture 30 days after liming, it is necessary a precipitation that provides the elevation of the soil moisture to 75% of the maximum soil water retention capacity.