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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Water storage in wetted strips under irrigated coffee trees with different criteria of irrigation management(Associação Brasileira de Engenharia Agrícola, 2013-03) Colombo, Alberto; Alvarenga, Lívia A.; Scalco, Myriane S.; Ribeiro, Randal C.; Abreu, Giselle F.The increasing demand for water resources accentuates the need to reduce water waste through a more appropriate irrigation management. In the particular case of irrigated coffee planting, which in recent years presented growth with the predominance of drip irrigation, the improvement of drip irrigation management techniques is a necessity. The proper management of drip irrigation depends on the knowledge of the spatial pattern of soil moisture distribution inside the wetted strip formed under the irrigation lines. In this study, grids of 24 tensiometers were used to determine the water storage within the wetted strip formed under drippers, with a 3.78 L h -1 discharge, evenly spaced by 0.4 m, subjected to two different management criteria (fixed irrigation interval and 60 kPa tension). Estimates of storage based on a one-dimensional analysis, that only considers depth variations, were compared with two-dimensional estimates. The results indicate that for high-frequency irrigation the one-dimensional analysis is not appropriate. However, under less frequent irrigation, the two-dimensional analysis is dispensable, being the one-dimensional sufficient for calculating the water volume stored in the wetted strip.Item Planos de amostragem no desenvolvimento inicial do cafeeiro sob irrigação(Departamento de Engenharia Agrícola - UFCG, 2005-10) Morais, Augusto R. de; Scalco, Myriane S.; Colombo, Alberto; Faria, Manoel A. de; Carvalho, Carlos H. M. de; Paiva, Leandro C.Este trabalho teve por objetivo avaliar características de plantas de café cultivar Rubi-MG1192 e, através da variabilidade dessas características, estabelecer planos de amostragem para orientar projetos na cultura do café, em desenvolvimento inicial. O experimento está instalado na área experimental do Departamento de Agricultura da Universidade Federal de Lavras, em Lavras, MG. O delineamento experimental foi em blocos casualizados, com quatro repetições, e os tratamentos constam das combinações de densidades de plantio definidas pelos espaçamentos 2500 (4,0 x 1,0 m), 3000 (3,0 x 1,0 m), 5000 (2,0 x 1,0 m), 10000 (2,0 x 0,5 m) e 20000 (1,0 x 0,5 m) e critérios para início das irrigações (-20, -80, -140 e -200 kPa, manejo SISDA 3-5 Ò e sem irrigação). Foram estabelecidos vários planos de amostragem para as variáveis altura de planta, diâmetro de caule e diâmetro de copa em função de diferentes números de repetições e de plantas por parcela. Há redução no coeficiente de variação com o aumento do número de plantas por parcela. O diâmetro de caule apresentou maior variabilidade que altura de planta. As estimativas das diferenças mínimas significativas entre duas médias de tratamentos decrescem com aumento do número de repetições e com o aumento do número de plantas por parcela.Item Drip irrigation in coffee crop under different planting densities: growth and yield in southeastern Brazil(Departamento de Engenharia Agrícola - UFCG, 2014-11) Assis, Gleice A. de; Scalco, Myriane S.; Guimarães, Rubens J.; Colombo, Alberto; Dominghetti, Anderson W.; Matos, Nagla M. S. deIrrigation associated to reduction on planting spaces between rows and between coffee plants has been a featured practice in coffee cultivation. The objective of the present study was to assess, over a period of five consecutive years, influence of different irrigation management regimes and planting densities on growth and bean yield of Coffea arabica L.. The treatments consisted of four irrigation regimes: climatologic water balance, irrigation when the soil water tension reached values close to 20 and 60 kPa; and a control that was not irrigated. The treatments were distributed randomly in five planting densities: 2,500, 3,333, 5,000, 10,000 and 20,000 plants ha -1 . A split-plot in randomized block design was used with four replications. Irrigation promoted better growth of coffee plants and increased yield that varied in function of the plant density per area. For densities from 10,000 to 20,000 plants ha -1 , regardless of the used irrigation management, mean yield increases were over 49.6% compared to the non-irrigated crop.