Poda programada de ciclo do cafeeiro arábica: ciclagem biogeoquímica, crescimento e produção
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Data
2021-07-28
Autores
Souza, Matheus Fonseca de
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Universidade Federal do Espírito Santo
Resumo
The study of productive and morphophysiological traits of coffee tree has been useful in the definition process of more efficient fertilization, according to nutritional demands and, also the efficiency of use of applied fertilizers and the fraction of nutrients supplied by cycling and soil. Thus, the aim of this study was to evaluate the nutrients biogeochemical cycling promoted by Programmed Cycle Pruning (PCP), and its contribution to vegetative development and production in arabica coffee, cultivated under different levels of nitrogen and potassium fertilization. The study was developed in Martins Soares city, Espírito Santo State, Brazil, at the Centro de Pesquisas Cafeeiras Eloy Carlos Heringer, located at 750 m altitude, with geographic coordinates 20º14'30"S and 41º50'44"W in an arabica coffee plantation. The genetic material studied was the cultivar Catuaí Vermelho IAC 44, with intermediate maturation, with eight years of age, conducted in a spacing of 2.5 x 0.6 m, with a population of 6666 plants per hectare. The first chapter aimed to evaluate the nutrient cycling capacity promoted by PCP in arabica coffee, submitted to four levels of N fertilization in the soil. The biomass and nutrient content experiment was carried out in randomized blocks, with 4 treatments and 4 replications, with four levels of N fertilization (50, 100, 150 and 200% of the recommended standard fertilization for arabica coffee). The experiment of decomposition, mineralization and nutrient release was carried out in a randomized block design with 4 replications, in a split plot in time schemes, the plots being composed of four levels of N fertilization (50, 100, 150 and 200%) and the subplots consisting of ten decomposition times (0, 30, 60, 90, 120, 150, 180, 240, 300 and 360 days). The biomass production from PCP was 1.12, 1.36, 1.28 and 1.48 t ha-1 of leaf dry matter and 2.14, 2.11, 1.98, 2.29 t ha-1 of branches dry matter in treatments 50, 100, 150 and 200% of N, respectively. The average decomposition of the leaves resulting from PCP was 76.6%, remaining 23.4% of initial weight during the period of 360 days. The biogeochemical cycling of macronutrients N, P, K, Ca and Mg was 43.02, 2.15, 39.19, 62.32 and 8.11 kg ha-1 , respectively. The second chapter aimed to evaluate the vegetative and productive development of arabica coffee conducted by PCP, submitted to four levels of N and K fertilization in the soil. The experiment was carried out in a factorial scheme, 4 x 4, in a randomized block design. Both the first factor and the second factor corresponded to four levels of N and K fertilization (50, 100, 150 and 200%), of the standard recommended fertilization for arabica coffee. The length of orthotropic branches, number of plagiotropic branches, length of plagiotropic branches, number of nodes per plagiotropic branch, productivity, grain yield, fruits float percentage, fruits green percentage, ripe and dry fruits were evaluated. Joint statistical analysis were performed for the variables studied for the years 2019 and 2020. No functional relationship was observed (Equation that tries to explain the variation of the dependent variable by the variation of the levels of the independent variable) between N and K for the length of orthotropic branches, number of plagiotropic branches and length of plagiotropic branches. However, number of nodes per plagiotropic branch increased as a function of N and K in a quadratic functional relationship. Productivity linearly increased as a function of potassium levels until reaching 88.78 bags (of 60 kilograms) per hectare for the 200% K level and increased as a function of nitrogen up to the maximum point for the 193.4% N level and then decrease. The percentage of ripe coffee linearly increased as a function of nitrogen and potassium in a quadratic functional relationship. There was no significant functional relationship between grain yield, fruits float percentage, dry fruits percentage, green coffee percentage and grain size with N and K.
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Adubação , biomassa , crescimento , decomposição , mineralização , nutrição