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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Organic matter fractions in soil under coffee with split applications of phosphorus and water regimes(Departamento de Engenharia Agrícola - UFCG, 2014-10) Araújo, Larissa G.; Figueiredo, Cícero C. de; Borges, Inácio B.; Ramos, Maria L. G.; Rocha, Omar C.; Guerra, Antonio F.Phosphorus fertilization and irrigation management are essential practices to increase coffee yields, though information is scarce about the effect of these practices on organic matter fractions of soils of the ‘Cerrado’ (savanna-like vegetation). The purpose of this study was to evaluate organic matter fractions of a clayey Oxisol under coffee with split applications of phosphorus (P) and water regimes. The experimental design was a randomized block with 3 x 2 factorial arrangement with three split applications of P (P1: 300 kg ha -1 P2O5 applied annually of which 2/3 applied in September and 1/3 in December; P2: 600 kg ha -1 P2O5 applied at planting and every two years, and P3: 1800 kg ha -1 of P2O5 applied only at planting, corresponding to a 6-year requirement), two water regimes (with and without irrigation) and three replications. Soil from the 0-5 and 5-10 cm layers was sampled. The total organic carbon (TOC), labile carbon (LC), microbial carbon (Cmic), and carbon fractions of fulvic acid (FA), humic acid (HA) and humin (HU) were determined. The irrigation regime of coffee increased the TOC, LC and Cmic levels and the humified fractions of soil organic matter. In general, the form of P splitting had little influence on the fractions of soil organic matter.Item Doses of phosphorus associated with nitrogen on development of coffee seedlings(Editora UFLA, 2014-07) Santinato, Felipe; Caione, Gustavo; Tavares, Tiago Oliveira; Prado, Renato de MelloA greater supply of nitrogen in the substrate using organic compost for coffee (Coffea arabica L.) seedlings can increase the effects of phosphorus in the plant and thereby promoting growth of biomass, enhancing the growth of plants when they are transplanted into the growing environment. The objective was evaluate the effect of phosphorus levels higher than those usually recommended in the absence and presence of nitrogen supplementation in the preparation of substrate containing organic compound to produce coffee seedlings grown in bags. The experiment was installed at a nursery in Araxá city, Minas Gerais State, Brazil in may 2011, using substrate containing 70 % of soil samples and 30 % of cattle manure, with the addition of 1 kg m -3 of potassium chloride and 1 kg m -3 of dolomitic lime. We used coffee seedlings of Catuaí Vermelho cultivar IAC 144 grown in polyethylene bags (1694 cm 3 ). The experiment was installed in a completely randomized design with four replicates and 12 treatments in a 6 x 2 factorial scheme, with six levels of phosphorus (P): 0, 109, 218, 436, 872 and 1308 mg dm -3 , as triple superphosphate; and two levels of nitrogen (N): absence and 100 mg dm -3 in the form of urea. The biometric variables, seedlings quality indexes, soil P concentration as well as accumulation of N and P by plants were determined at 180 days after sowing. Through regression analysis to conclude that the application of phosphorus in the substrate enhanced the P concentration in soil and plant, reflecting in the growth and dry matter production of coffee seedlings, especially in the presence of nitrogen. The highest tested dose of phosphorus (1308 mg dm -3 ) is the most appropriate dose for the production of coffee seedlings. The addition of nitrogen to the substrate containing cattle manure is important to supply the need of this nutrient in the seedlings.