Revista Brasileira de Engenharia Agrícola e Ambiental

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10362

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Resultados da Pesquisa

Agora exibindo 1 - 10 de 10
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    Performance of a variable-rate distribution system for simultaneous fertilizer application
    (Departamento de Engenharia Agrícola - UFCG, 2016) Barros, Murilo M. de; Volpato, Carlos E. S.; Silva, Fabio M. da; Conceição, Fagner G. da; Corrêa Júnior, Delorme; Ribeiro, Luiz F.
    The objective of this study was to evaluate the performance of a variable-rate fertilizer distribution system for coffee crop, simultaneously applying two products. Two types of tests were performed: transversal deposition and longitudinal deposition. The transversal deposition test, with tarps, aimed to quantify the variations between programmed and applied doses, using a completely randomized design (CRD), in a factorial scheme, and the Scott-Knott test at p < 0.05. The longitudinal deposition test aimed to determine the distribution characteristics of the equipment along the displacement line, based on relative frequency values. In addition, the application rates on both sides of the distribution system were analysed using a CRD and the Scott-Knott test at p < 0.05. The application variation in the transversal deposition test with tarps was 1.59%. The variable-rate distribution system remained stable regarding the longitudinal deposition, regardless of any interaction.
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    Nicotinamide and Azospirillum brasilense improves the quality of Coffea arabica seedlings
    (Departamento de Engenharia Agrícola - UFCG, 2023-01-06) Lima, Sebastião F.; Pinto, Pedro H. G.; Soares, Manoel P. L.; Andrade, Maria G. de O.; Simon, Cátia A.; Vendruscolo, Eduardo P.; Contardi, Lucymara M.; Cordeiro, Meire A. S.; Abreu, Mariele S.
    The use of biostimulants in coffee seedlings can promote gains in their growth and quality. Thus, this study aimed to evaluate the growth and quality characteristics of Coffea arabica seedlings under the effect of the nicotinamide and Azospirillum brasilense application. The experimental design was randomized blocks with treatments arranged in a 5 × 2 factorial scheme, with four replicates. The treatments resulted from the use of five doses of nicotinamide (0, 30, 60, 90, and 120 mg L-1 of water) combined with the absence and presence of Azospirillum brasilense applied to Coffea arabica seedlings from Catuaí Vermelho 144 cultivar. Plant height, stem diameter, number of leaves, leaf area, shoot dry mass, root dry mass, plant height:stem diameter ratio, shoot:root dry mass ratio, plant height:shoot dry mass ratio, and Dickson quality index were evaluated. The combined or isolated use of A. brasilense and nicotinamide, up to a dose of 33.5 mg L-1, increased the biometric characteristics and dry mass accumulation. However, using nicotinamide doses between 30 and 61.8 g L-1 increased the quality of Coffea arabica seedlings. The synergistic effect of the use of A. brasilense and nicotinamide was verified for the growth and quality of Coffea arabica seedlings.
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    Litterfall decomposition of coffee shaded with Tectona grandis or in full sun
    (Departamento de Engenharia Agrícola - UFCG, 2022-01-14) Henrique, Nirvani S.; Maltoni, Katia L.; Faria, Glaucia A.
    Litterfall is an important source of soil nutrients, but its decomposition can be affected by the crop system used. The objective of this study was to evaluate litterfall decomposition and macronutrient stocks in coffee crop systems in shaded (SHCS) environments and those in full sun (FSCS). The experiment was conducted on a rural property in Cacoal, state of Rondônia, Brazil, in a 2 × 6 factorial scheme with two crop systems (SHCS and FSCS), and six litterfall decomposition evaluation times (0, 30, 60, 180, 300, and 360 days after the litterfall was returned to the soil (DAL)), with seven replicates. The constant of decomposition (k), half-life time (t1/2) at 360 DAL, and phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and nitrogen (N) concentrations of the remaining litterfall were determined at each evaluation time. The litterfall in the SHCS had a greater weight loss and constant of decomposition and a lower half-life time at the last evaluation, and the weight loss increased as a function of decomposition time. The litterfall stocks of macronutrients N, P, K, Ca, and Mg showed a linear decrease throughout the decomposition time, and increases in sulfur stock were found at the last evaluation.
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    Nutritional balance and its relationship to yield in a coffee field: Inferences from geospatial analysis
    (Departamento de Engenharia Agrícola - UFCG, 2020) Silva, Marcelo B. da; Partelli, Fábio L.; Gontijo, Ivoney; Caldas, Marcellus M.
    Information obtained from studies of spatial variability and the Diagnosis and Recommendation Integrated System (DRIS) may contribute to understanding better the relationship between mineral nutrient balance and factors that limit the crop yield. This study shows that nutritionally balanced plants may be associated with low productivity in Conilon coffee fields. The study was carried out on a highly productive Conilon coffee (Coffea canephora) field, in São Mateus, state of Espírito Santo, Brazil. A sample grid was established with 100 points, each point linked to one plant. Twenty pairs of leaves from each plant were collected from productive branches to create a sample for nutritional analysis. The rust incidence (Hemileia vastatrix), the presence of the coffee borer (Hypothenemus hampei), and the physical characteristics of the soil were evaluated in each sampled plant. DRIS and Nutrient Balance Index (NBI) were calculated, and from the yield data, they were characterized using descriptive statistics. Maps were created showing the spatial distribution of the NBI, yield, total sand, and incidence of rust and coffee borer. It was verified the low relationship between nutritional balance and yield in Conilon coffee, suggesting that non-nutritional factors also influenced plant production. In areas of the maps with high NBI, the plant’s nutritional balance was the main limiting factor of production, since most plants in this area produced less than the average productivity of the plants sampled. The use of a geostatistics tool combined with the NBI resulted in better understanding of the relationship between nutritional and non-nutritional variables on the Conilon coffee yield.
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    Soil quality in two coffee crop systems in the Amazon biome
    (Departamento de Engenharia Agrícola - UFCG, 2020) Henrique, Nirvani S.; Maltoni, Katia L.; Faria, Glaucia A.
    The form of occupation of the state of Rondônia, Brazil, favored the extensive agriculture, which resulted in a fast deforestation. The removal of forests and inadequate soil management and use, combined with a hot and wet climate, affected the soil chemical, physical, and biological attributes. In search for less impacting and alternatives that promote greater soil conservation for coffee production in the North region of Brazil, the objective of this work was to evaluate the effects of two coffee crop systems on the soil chemical and microbiological attributes. The treatments consisted of a shaded coffee crop (SCC) and a full-sun coffee crop (FCC). A completely randomized design was used, with four clusters per treatment and seven sampling points per cluster, which constituted a replication, totaling 28 replications per treatment. The data were collected in April 2018, in a rural property in the municipality of Cacoal, state of Rondônia, Brazil (11º21’50’’S, 61º20’10’’W, and altitude of 238 m). The soil organic matter, pH, P, K, Ca, Mg, Al, H+Al, base saturation, and basal respiration were determined. The soil under SCC had higher Ca content, pH, and base saturation, and lower potential acidity (H+Al) and Al content than that under FCC. The litterfall on the soil under FCC presented higher N and Mg contents. The soil basal respiration increased in the first 5 cm depth in the treatment with SCC.
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    Resposta do cafeeiro à aplicação de níveis de irrigação e adubação com Alfertil
    (Departamento de Engenharia Agrícola - UFCG, 2013-04) Evangelista, Adão W. P.; Alves Júnior, José; Melo, Paulo C. de
    Propôs, neste trabalho, avaliar os efeitos da irrigação e a aplicação do fertilizante Alfertil ® sobre a produtividade e rendimento do cafeeiro. O delineamento estatístico utilizado foi o de blocos casualizados, com parcelas subdivididas contendo quatro repetições. As parcelas receberam tratamentos constituídos de quatro lâminas de irrigação calculadas com base em percentagens de evaporação do tanque Classe A (ECA) ou seja: L 0 = 0 (Testemunha); L 40 = 40%ECA; L 80 = 80%ECA e L 120 = 120%ECA e as subparcelas receberam os tratamentos de adubação constituídos de três formas de aplicação de Alfertil ® , sendo: A 0 = Testemunha (S/Alfertil ® ); A f = via foliar (Alfertil ® na forma líquida na concentração de 5% peso/peso) e A s = via solo (100 g cova -1 planta -1 na forma pó). Verificou-se que a produtividade do cafeeiro foi influenciada pelos tratamentos de irrigação e formas de aplicação de Alfertil ® enquanto somente as diferentes lâminas de irrigação influenciaram o rendimento do cafeeiro. As lâminas de irrigação que maximizam a produtividade e o rendimento do cafeeiro foram as estimadas em 60,08 e 70,20% da ECA, respectivamente, e as plantas adubadas com Alfertil ® via foliar ou solo promoveram aumento na produtividade do cafeeiro.
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    Doses de fósforo e irrigação na nutrição foliar do cafeeiro
    (Departamento de Engenharia Agrícola - UFCG, 2014-12) Dominghetti, Anderson W.; Scalco, Myriane S.; Guimarães, Rubens J.; Silva, Douglas R. G.; Carvalho, João P. S.; Pereira, Vinícius A.
    O objetivo deste trabalho foi avaliar, em doses crescentes de fósforo, o efeito de lâminas de irrigação no teor foliar de fósforo de cafeeiros em estágio de primeiro ano de produção. O plantio (Topázio MG–1190) foi realizado em janeiro de 2010 e os tratamentos diferenciados a partir de novembro de 2011. Utilizou-se o delineamento experimental em blocos ao acaso com três repetições, com tratamentos dispostos no esquema fatorial 5 x 4 os quais se compunham por cinco lâminas de irrigação correspondentes às frações (0,4; 0,7; 1,0; 1,3 e 1,6) da lâmina calculada pelo coeficiente de cultura e quatro doses de fósforo (0, 80, 240 e 720 kg ha -1 ). Foi utilizado o sistema de irrigação por gotejamento enquanto a adubação fosfatada (monoamônio fosfato purificado) foi feita via fertirrigação, em doze parcelamentos iguais durante o ano. Foram avaliados os teores foliares de fósforo aos dois, quatro, seis, oito, dez e doze meses após o início dos tratamentos. Tanto em aplicação única de fósforo, no plantio, quanto na aplicação de doses crescentes parceladas via fertirrigação, observou-se que no primeiro ano de produção o teor foliar de fósforo de cafeeiros aumenta com aumento da lâmina de irrigação.
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    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.
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    Distribuição espacial das raízes de cafeeiro e dos poros de dois Latossolos sob manejo conservacionista
    (Departamento de Engenharia Agrícola - UFCG, 2014-03) Carducci, Carla E.; Oliveira, Geraldo C. de; Lima, José M.; Rossoni, Diogo F.; Costa, Alisson L. da; Oliveira, Larissa M.
    O objetivo deste trabalho foi avaliar o efeito do sistema de manejo que emprega práticas de conservação do solo na distribuição do sistema radicular de cafeeiros e na estrutura de dois Latossolos após seis anos de implantação da lavoura na região do Alto São Francisco, MG. Foram abertas três trincheiras aleatórias e longitudinais à linha de plantio (0,70 x 1,50 m) em um Latossolo gibbsítico e em um Latossolo caulinítico ambos sob sistema de manejo do solo que emprega práticas conservacionistas. A avaliação do sistema radicular foi feita pelo método do perfil cultural e análise digital de imagens 2D, com posterior confecção de mapas de superfície das variáveis radiculares analisadas por meio da krigagem. Amostras de solo com estrutura preservada foram coletadas para quantificar a distribuição do diâmetro de poros 3D obtida por tomografia computada de raios-X. As raízes e poros foram classificados em: 1, >1 e ≤ 3 e > 3 mm de diâmetro. O sistema radicular dos cafeeiros de ambos os solos em estudo mesmo sobre o mesmo sistema de manejo apresentaram boa ramificação na direção horizontal e vertical. A maior concentração de raízes ocorreu na profundidade de 0,20-0,34 m no Latossolo caulinítico. No Latossolo gibbsítico, a distribuição radicular foi uniformizada especialmente na direção vertical do perfil do solo atingindo maiores profundidade. A maior ocorrência de raízes finas ocorreu no Latossolo gibsítico na profundidade de 0,80-0,94 m.
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    Nitrogen dynamics in a Latosol cultivated with coffee
    (Departamento de Engenharia Agrícola - UFCG, 2018-06) Souza, José A.; Rocha, Genelício C.; Gomes, Mateus de P.; Rezende, Carlos H. S.
    The objective of this study was to evaluate nitrogen losses by NH 3 volatilization and quantify the upward and downward NO 3- flows in Latosol cultivated with arabica coffee. An experiment was set in 2010, in Viçosa-MG, Brazil (20 o 41’ S and 42 o 48’ W), in a randomized block design in a (3 x 2) + 1 factorial arrangement with three nitrogen doses (200, 400 and 600 kg ha -1 ), two forms of urea (conventional and NBPT urease inhibitor-treated) and one additional treatment without nitrogen fertilization, with four replicates. Semi-open type chambers were installed to quantify NH 3 volatilization. To determine the concentration and flow of NO 3- a soil solution extractor was installed in each plot at a 1-m depth together with three tensiometers at depths of 0.90, 1.00 and 1.10 m. Nitrogen losses by volatilization were 3.51 and 11.21% for NBPT-treated urea and conventional urea, respectively. The rainfall (1172 mm), its distribution and the dose strongly influenced the losses by leaching. Urease inhibitor-treated urea led to higher risk of groundwater contamination with NO 3- . Returns of NO 3- occur in periods of drought, but it is not possible to state if this NO 3- can be used by the plant because, under these conditions, the soil has low moisture content, which may compromise the absorption.