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Carvalho,Daniel F. de; Lima,Marcio E. de; Oliveira,Alexsandra D. de; Rocha,Hermes S. da; Guerra,José G. M.. |
Under organic management in Seropédica-RJ, Brazil, using a weighing lysimeter, the crop coefficients (kc), the maximum evapotranspiration and the productivity of eggplant cultivation under two cropping systems (no tillage with straw plus soil with conventional preparation) were determined. A whole randomized layout with two treatments (no tillage and conventional) and five replicates during 134 days of cultivation were adopted. There were no significant differences in the eggplant cultivation in the two cropping systems, with a maximum commercial productivity obtained from 47.42 Mg ha-1 for the no-tillage system, and 47.91 Mg ha-1 for the conventional tillage. The accumulated ETc was 285.15 and 323.44 mm for the no-tillage and conventional, respectively.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Solanum melongena L.; Weighing lysimeter; Irrigation. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000400018 |
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Carvalho,Daniel F. de; Silva,Dione G. da; Rocha,Hermes S. da; Almeida,Wilk S. de; Sousa,Eraldo da S.. |
The aim of this study was to quantify the water consumption and the crop coefficients (Kc) for the potato (Solanum tuberosum L.), in Seropédica, Rio de Janeiro (RJ), Brazil, under organic management, and to simulate the crop evapotranspiration (ETc) using the Kc obtained in the field and the ones recommended by the Food and Agriculture Organization (FAO). The water consumption was obtained through soil water balance, using TDR probes installed at 0.15m and 0.30m deep. At the different stages of development, the Kc was determined by the ratio of ETc and reference evapotranspiration, obtained by Penman-Monteith FAO 56. The crop coefficients obtained were 0.35, 0.45, 1.29 and 0.63. The accumulated ETc obtained in the field was 109.6 mm, while the ETc... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Solanum tuberosum L.; Time domain reflectometry; Irrigation. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000100020 |
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Carvalho,Daniel F. de; Silva,Dione G. da; Souza,Adilson P. de; Gomes,Daniela P.; Rocha,Hermes S. da. |
A evapotranspiração de referência (ETo) é dependente da quantidade de energia disponível no ambiente e a radiação solar (Rs) é uma variável importante na sua estimativa. Mediante o exposto, o presente trabalho teve como objetivo determinar os coeficientes "a" e "b" da equação de Angströn-Prescott para Seropédica, RJ, e avaliar seus efeitos na estimativa da Rs e da ETo. Utilizaram-se medidas da radiação solar global e número efetivo de horas de brilho solar da estação Ecologia Agrícola (83741 -INMET) do período de 2000 a 2007. Os coeficientes foram determinados por análise de regressão linear, para todo o período e para períodos mensais e anuais. Utilizando-se os coeficientes calculados e os propostos pela FAO (0,25 e 0,50) estimaram-se Rs e ETo, e se... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Radiação solar; Brilho solar; Estação meteorológica; Penman-Monteith. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662011000800011 |
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Rocha,Hermes S. da; Marques,Patricia A. A.; Camargo,Antonio P. de; Frizzone,José A.; Saretta,Ezequiel. |
ABSTRACT Assuming that a roughness meter can be successfully employed to measure the roughness on the internal surface of irrigation pipes, this research had the purpose of defining parameters and procedures required to represent the internal surface roughness of plastic pipes used in irrigation. In 2013, the roughness parameter Ra, traditional for the representation of surface irregularities in most situations, and the parameters Rc, Rq, and Ry were estimated based on 350 samples of polyvinyl chloride (PVC) and low-density polyethylene (LDPE) pipes. Pressure losses were determined from experiments carried out in laboratory. Estimations of pressure loss varied significantly according to the roughness parameters (Ra, Rc, Rq, and Ry) and the corresponding... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Friction factor; Head loss; Roughness meter. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000300143 |
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Rocha,Hermes S. da; Marques,Patricia A. A.; Camargo,Antonio P. de; Reis,Douglas L. dos; Silva,Eric A. da; Frizzone,José A.. |
ABSTRACT Laboratory tests for technical evaluation or irrigation material testing involve the measurement of many variables, as well as monitoring and control of test conditions. This study, carried out in 2016, aimed at using statistical quality control techniques to evaluate results of dripper tests. Exponentially weighted moving average control charts were elaborated, besides capability indices for the measurement of the test pressure and water temperature; and study on repeatability and reproducibility (Gage RR) of flow measurement system using 10 replicates, in three work shifts (morning, afternoon and evening), with 25 emitters. Both the test pressure and water temperature remained stable, with “excellent” performance for the pressure adjustment... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dripper flow; Statistical process control; Repeatability and repro; Control charts; Stability and capability; For measurement process. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000900587 |
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