SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Heermann, Dale F.; Jensen, Marvin E..

An irrigation controller mechanically actuated by soil-water tension: I - Design, development and laboratory evaluations

Palavras-chave: Irrigation scheduling; Mass Import - autoclassified (may be erroneous).

Ano: 1970

URL: http://eprints.nwisrl.ars.usda.gov/984/1/216.pdf

AGRIAMBI

Almeida,Alexsandro C. S.; Botrel,Tarlei A.; Raine,Steven R.; Camargo,Antonio P. de; Pinto,Marinaldo F.; Salvador,Conan A..

ABSTRACT The objective of this study was to develop and evaluate an irrigation controller that was mechanically actuated by soil-water tension within laboratory conditions. The controller was designed and constructed using readily available hydraulic fittings and other componentry. The main components of the controller were a tensiometer; a rubber diaphragm that moves according to the variation in tension inside of the tensiometer; an activation rod that transfers the movement from diaphragm to the switch valve; and a steel spring that regulates the activation of soil water tension. Six irrigation controller samples were tested in the laboratory to evaluate the mechanical performance and component forces required to activate the controllers. The...

Análise de crescimento do crisântemo de vaso, cultivar Puritan, irrigado em diferentes tensões de água em ambiente protegido - doi: 10.4025/actasciagron.v33i1.1763

Palavras-chave: Irrigation scheduling; Tensiometer; Automation.

Ano: 2017

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000600369

Agronomy

Farias, Maryzélia Furtado de; Centro de Ciências Agrárias da Universidade Federal do Maranhão; Saad, João Carlos Cury; Universidade Estadual Paulista.

A irrigação é prática fundamental para o cultivo de crisântemo, porém seu manejo adequado tem sido negligenciado pelos produtores, resultando em prejuízos no crescimento vegetal e conseqüentes decréscimos na produtividade e na qualidade do produto final. Para melhorar a representatividade dos dados obtidos, o experimento foi desenvolvido na propriedade de um produtor tradicional, no Distrito de Holambra II, município de Paranapanema-SP (23°4’S e 49°00’W). O objetivo principal do trabalho foi identificar a tensão de água no substrato (potencial matricial) que resultasse em melhor crescimento e desenvolvimento do crisântemo em vaso, cultivar Puritan. Os tratamentos foram definidos por seis níveis de tensão de água no substrato: -2, -3, -4,-...

Palavras-chave: 5.00.00.00-4 Dendranthema grandiflora; Manejo de água; Tensão de água no substrato 5.01.00.00-9 Dendranthema grandiflora; Irrigation scheduling; Substrate water tension.

Ano: 2011

URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/1763

Assessing irrigation performance with comparative indicators: The case of the Alto Rio Lerma Irrigation District, Mexico

Kloezen, Wim H.; Garces-Restrepo, Carlos.

Describes and evaluates the application of IWMI's minimum set of performance indicators to the Alto Rio Lerma Irrigation District, and compares this with the application of a small set of process performance indicators.

Tipo: Report

Palavras-chave: Irrigation management; Irrigation scheduling; Water allocation; Water distribution; Case studies; Institutional constraints; Operation; Monitoring; Indicators; Performance indexes; Water rights; Economic aspects; Data collection; Environmental effects; Performance evaluation; Water use efficiency; Crop Production/Industries; Institutional and Behavioral Economics; Production Economics.

Ano: 1998

URL: http://purl.umn.edu/44580

Balancing irrigation and hydropower: Case study from Southern Sri Lanka

Molle, Francois; Jayakody, Priyantha; Ariyaratne, Badugodahewa Ranjith; Somatilake, H.S..

This report analyzes a case from southern Sri Lanka, where the Samanalawewa dam and the Kaltota Irrigation Scheme (KIS) compete for the water of the Walawe river. At the catchment level, it is shown that dam releases are well attuned to the needs of KIS and to the occurrences of natural runoff, and that little of the dam water is "lost" to the river.

Tipo: Report

Palavras-chave: Reservoirs; Dams; Hydroelectric schemes; Economic analysis; Canals; Irrigation scheduling; Cropping systems; Case studies; Crop Production/Industries; Farm Management; Land Economics/Use.

Ano: 2005

URL: http://purl.umn.edu/44544

CALIBRATION OF THE HARGREAVES-SAMANI EQUATION FOR SPECIFIC PERIODS OF THE YEAR IN THE MUNICIPALITY OF JAÍBA-MG, BRAZIL

Engenharia na Agricultura

Duarte, Anunciene Barbosa; Ferreira, Lucas Borges; dos Santos, Edson Fagne.

Reference evapotranspiration (ET0) explains the climatic effects on crop water demand. The Food and Agriculture Organization (FAO) recommends the Penman Monteith equation as a standard method for estimating ET0. However, because this equation requires a large amount of meteorological data, it has limited application. An alternative is the Hargreaves-Samani (HS) equation, which only requires air temperature data, and can be calibrated to specifc locations and periods. The present study aimed to calibrate the empirical parameters (coeffcients and exponent) of the HS equation for specifc periods of the year, as well as evaluate the behavior and calibration of this equation throughout the year in the municipality of Jaíba-MG, Brazil. The daily meteorological...

Class A pan coefficients (Kp) to estimate daily reference evapotranspiration (ETo)

Palavras-chave: Metereologia Agrícola evapotranspiration; Irrigation scheduling; Missing data; Temperature.

Ano: 2017

URL: http://www.seer.ufv.br/seer/index.php/reveng/article/view/838

AGRIAMBI

Sentelhas,Paulo C.; Folegatti,Marcos V..

The class A pan coefficient (Kp) has been used to convert pan evaporation (ECA) to grass-reference evapotranspiration (ETo), an important component in water management of irrigated crops. There are several methods to determine Kp values, using wind speed, relative humidity and fetch length and conditions. This paper analyses the following methods to estimate Kp values: Doorenbos & Pruitt (1977); Cuenca (1989); Snyder (1992); Pereira et al. (1995); Raghuwanshi & Wallender (1998); and FAO/56 (Allen et al., 1998). The estimated values of Kp and the observed Kp, obtained from the relationship between ETo measured in a weighing lysimeter and ECA measured in a class A pan, were compared by regression analysis. The same routine was adopted to...

Crop yield models adapted to irrigation scheduling programs

Palavras-chave: Pan coefficient; Irrigation scheduling; Weighing lysimeter.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662003000100018

Development and Evaluation of Evapotranspiration Models for Irrigation Scheduling

Hill, R.W.; Hanks, R.J.; Wright, J.L..

Please contact the NWISRL if you have a copy of this publication.

Tipo: Technical Bulletin

Palavras-chave: Irrigation scheduling; Research methodology; Mass Import - autoclassified (may be erroneous).

Ano: 1985

Wright, James L.; Jensen, Marvin E..

Tipo: Article

Palavras-chave: Irrigation scheduling; Evapotranspiration; Research methodology; Mass Import - autoclassified (may be erroneous).

Ano: 1978

URL: http://eprints.nwisrl.ars.usda.gov/331/1/393.pdf

Farmer response to rationed and uncertain irrigation supplies

Perry, Christopher J.; Narayanamurthy, S.G..

Explores the theoretical and actual responses of farmers faced with irrigation supplies that are limited in relation to available land and labor resources, and where the actual schedule and available volume for delivery are uncertain.

Tipo: Report

Palavras-chave: Water resource management; Water use efficiency; Evapotranspiration; Agricultural production; Irrigated farming; Irrigation scheduling; Water allocation; Water supply; Water scarcity; Water delivery; Reservoirs; Uncertainty; Yield; Crop Production/Industries; Labor and Human Capital; Land Economics/Use.

Ano: 1998

URL: http://purl.umn.edu/44582

Gaseous irrigation control system: descriptions and phisical tests for performance assessment

Bragantia

Calbo,Adonai Gimenez; Silva,Washington Luiz de Carvalho e.

Irrigas is a water tension measuring system made out of a porous cup (sensor), connected to a gas pressurizing/measuring device by a flexible tube. Water tension (T) is obtained from the equation T=Td-p or T=Ts-p, where Td is the sensor desorption critical water tension (bubbling beginning), Ts is the sensor sorption critical water tension (bubbling ceasing) and p is the applied gas pressure. Differently from conventional tensiometers, the irrigas porous cup cavity is filled with air. This characteristics makes the irrigas system nearly maintenance free and also eliminates the need of making hydrostatic pressure corrections for sensor depth. The system was tested both in the desorption and sorption modes. In the first case the Richards pressure chamber was...

How Scheduling Fits in the Irrigation Program in the Grand Valley of Colorado

Palavras-chave: Irrigas; Irrigation scheduling; Porous cup; Tensiometer; Water tension.

Ano: 2006

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052006000300017

Boesch, Brice E.; Humpherys, Allan S.; Young, David.

Infrared thermometry to schedule irrigation of common bean

Palavras-chave: Irrigation scheduling; Mass Import - autoclassified (may be erroneous).

Ano: 1981

URL: http://eprints.nwisrl.ars.usda.gov/1024/1/471.pdf

PAB

Lobo,Francisco de Almeida; Oliva,Marco Antonio; Resende,Morethson; Lopes,Nei Fernandes; Maestri,Moacyr.

The objective of this work was to determine the critical irrigation time for common bean (Phaseolus vulgaris L. cv. Carioca) using infrared thermometry. Five treatments were analyzed. Canopy temperature differences between plants and a well-watered control about 1, 2, 3, 4, and 5±0.5ºC were tested. Physiological variables and plant growth were analyzed to establish the best time to irrigate. There was a significant linear correlation between the index and stomatal resistance, transpiration rate, and leaf water potential. Although significant linear correlation between the index and mean values of total dry matter, absolute growth rate, and leaf area index was found, no correlation was found with other growth index like relative growth rate, net...

Institutional perspectives of land reclamation operations in Punjab: A case study of the Lower Chenab Canal (East) Circle Area

Palavras-chave: Irrigation scheduling; Water use efficiency; Growth rate.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2004000200003

Bandaragoda, Don Jayatissa; Rehman, Saeed ur.

The Directorate of Land Reclamation (DLR), which was set up in 1945, is a special unit of Punjab's Irrigation and Power Department for undertaking research and field operations to combat the problem of salinity. Approaching the end of five decades of existence, the directorate is yet to demonstrate its effectiveness in its assigned task; its inability to fully cope with the conditions of a fast changing irrigation environment makes this rather an illusive goal. In the selection of lands for reclamation, the Directorate is heavily dependent on the visual salinity survey (Thur Girdawari) carried out every year by the Irrigation Department's field staff. This visual survey appears to be a quick and cost-effective method of assessing surface salinity, but...

Tipo: Working or Discussion Paper

Palavras-chave: Land reclamation; Soil salinity; Irrigated sites; Irrigation canals; Irrigation water; Institutions; Legal aspects; Irrigation scheduling; Water availability; Irrigated farming; Case studies; Farm Management; Land Economics/Use.

Ano: 1994

URL: http://purl.umn.edu/113011

Irrigation controller mechanically actuated by soil-water tension: II - Field evaluations

AGRIAMBI

Almeida,Alexsandro C. S.; Botrel,Tarlei A.; Raine,Steven R.; Camargo,Antonio P. de; Pinto,Marinaldo F.; Salvador,Conan A..

ABSTRACT In this study, a field evaluation of the performance of an irrigation controller mechanically actuated by soil-water tension (SWT) was performed. The controller employs a tensiometer used as a sensor of SWT to directly control a mechanically actuated hydraulic valve. Six controllers were installed in an orchard to control the irrigation for six rows of plants over 64 days. Each controller controlled the irrigation of one lateral drip line. The drip irrigation system was gravity-fed from a water source placed 7 m above the soil surface. The SWT and the pressure in each lateral line were measured to evaluate the performance of the controllers. All the controllers tested in the field autonomously initiated and terminated the irrigation during the...

Irrigation Scheduling for Farm Crops

Palavras-chave: Irrigation scheduling; Technological innovation; Tensiometer; Automation.

Ano: 2017

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500298

Jensen, M.E..

Irrigation Scheduling for Optimum Water Management

Palavras-chave: Irrigation scheduling; Mass Import - autoclassified (may be erroneous).

Ano: 1971

URL: http://eprints.nwisrl.ars.usda.gov/986/1/227.pdf

Lord Jr, J.M.; Jensen, M.E..

Irrigation Scheduling in Idaho

Palavras-chave: Irrigation scheduling; Water management; Mass Import - autoclassified (may be erroneous).

Ano: 1975

URL: http://eprints.nwisrl.ars.usda.gov/995/1/311.pdf

Jensen, Marvin E..