Comparison of hourly and daily Penman-Monteith grass- and alfalfa-reference evapotranspiration equations and crop coefficients for maize under arid climatic conditions

2017 ◽  
Vol 192 ◽  
pp. 1-11 ◽  
Author(s):  
X.B. Ji ◽  
J.M. Chen ◽  
W.Z. Zhao ◽  
E.S. Kang ◽  
B.W. Jin ◽  
...  
Keyword(s):  
Reference Evapotranspiration ◽  
Climatic Conditions ◽  
Crop Coefficients

scholarly journals Irrigation scheduling strategies for pepper based on evaporation and reference evapotranspiration

2021 ◽  
Vol 26 (51) ◽  
pp. 69-76
Author(s):  
Borivoj Pejić ◽  
Ivana Bajić ◽  
Ksenija Mačkić ◽  
Dušanka Bugarski ◽  
Slobodan Vlajić ◽  
...  
Keyword(s):  
Reference Evapotranspiration ◽  
Soil Layer ◽  
Open Water ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Vegetable Crops ◽  
Irrigation Water Use ◽  
Evapotranspiration Rate ◽  
Crop Coefficients ◽  
Novi Sad

The experiment with drip irrigated pepper was conducted at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad in 2019. The irrigation was scheduled on the basis of the water balance method. Two methods were used to compute the daily evapotranspiration of pepper (ETd): reference evapotranspiration (ETo) and evaporation from an open water surface (Eo). Crop coefficients (kc) and corrective coefficients (k) were used to convert ETo and Eo values into ETd. Kc and k were 0.3-0.4, 0.6-0.7, 0.9-1.1, 0.8-0.9 and 0.4, 0.7, 1.0 and 0.8 for initial stage, crop development, mid season, and late season, respectively. ETo was calculated by the Hargreaves equation. Eo values were measured by a Class-A pan located at a meteorological station near the experimental plot. Irrigation started when readily available water (RAW) in the 0.3 m soil layer was completely absorbed by plants. Differences in crop yield (Y) and irrigation water use efficiency (IWUE) obtained using Eo (42.58 t ha-1, 15.20 kg m-3) and ETo (40.78 t ha-1, 14.56 kg m-3) were not statistically different. Evapotranspiration rate was 364.2 mm and 337.3 mm in Eo and ETo variant, respectively. The fact that the differences in Y and IWUE between different calculations of ETd were not statistically significant indicates that both methods can be recommended for irrigation scheduling programs for pepper in the climatic conditions of the Vojvodina region. However, priority should be given to ETo due to the easy accessibility and reliability of data.

scholarly journals Coeficiente del cultivo de Vigna unguiculata L. Walp. cv. INIAP-463 para periodos secos y lluviosos utilizando lisimetría de drenaje

2020 ◽  
pp. 29
Author(s):  
Jesús Enrique Chavarría Párraga ◽  
Julio Cesar Ramírez-Caicedo ◽  
Jorge Isaac Zambrano-Kuffó ◽  
Richard Xavier Bravo-Ferrín ◽  
Luis Enrique Párraga-Muñoz
Keyword(s):  
Vigna Unguiculata ◽  
Reference Evapotranspiration ◽  
Climatic Conditions ◽  
Weather Station ◽  
Phenological Stage ◽  
Dry Period ◽  
Rainy Period ◽  
Palabras Clave ◽  
Crop Cycle ◽  
Crop Coefficients

Coefficient of Vigna unguiculata L. Walp. for dry and rainy periods in the Chone river valley Resumen El uso del agua en la agricultura es una actividad muy demandante a nivel mundial, por ello es necesario conocer la cantidad de agua que consumen los vegetales de interés agrícola. Se investigó el coeficiente del cultivo (Kc) de Vigna unguiculata L. Walp. (cv. INIAP-463) para periodos secos y lluviosos de Chone, Manabí, Ecuador a través de lisimetría de drenaje. Se ejecutó en el año 2019, implementándose tres lisímetros de drenaje cerca de la estación climatológica M0162. La lámina de riego fue aplicada en base a la evapotranspiración de referencia diaria (ETo). Se realizó el cálculo del Kc para cada etapa fenológica del cultivo determinando el cociente entre la evapotranspiración del cultivo (ETc) y ETo. El frejol presentó cuatro etapas según su consumo hídrico, reportando valores de Kc de 0,55; 0,92; 1,30 y 0,80 para el periodo seco y 0,45; 0,88; 1,28 y 0,75 para el periodo lluvioso. Las necesidades hídricas del frejol fueron 219,37 mm para el período seco y 237,82 mm para el período lluvioso durante 85 días que duró el ciclo del cultivo. Los valores de Kc y necesidades hídricas varían según las condiciones climáticas de las zonas en donde se desarrollen los cultivos. Palabras clave: evapotranspiración; lámina de drenaje; necesidades hídricas; riego; leguminosa. Abstract Water use in agriculture is a very demanding activity worldwide, therefore it is necessary to know the amount of water consumed by vegetables of agricultural interest. The crop coefficients (Kc) of Vigna unguiculata L. Walp was investigated. (cv. INIAP-463) for dry and rainy periods of Chone, Manabí, Ecuador through drainage lysymmetry. It was executed in 2019, implementing three drainage lysimeters near the M0162 weather station. The irrigation sheet was applied based on the daily reference evapotranspiration (ETo). Kc was calculated for each phenological stage of the crop by determining the quotient between the evapotranspiration of the crop (ETc) and ETo. The bean presented four stages according to its water consumption, reporting Kc values ​​of 0.55; 0.92; 1.30 and 0.80 for the dry period and 0.45; 0.88; 1.28 and 0.75 for the rainy season. The water needs of the beans were 219.37 mm for the dry period and 237.82 mm for the rainy period during the 85 days of the crop cycle. The Kc values ​​and water needs vary according to the climatic conditions of the areas where the crops are grown. Keywords: evapotranspiration; drainage sheet; irrigation; water needs; legume.

scholarly journals Evapotranspiration and crop coefficients of melon plants measured by lysimeter and estimated according to FAO 56 methodology

2013 ◽  
Vol 33 (5) ◽  
pp. 929-939 ◽  
Author(s):  
Talyana K. de Melo ◽  
José F. de Medeiros ◽  
José E. Sobrinho ◽  
Vladimir B. Figueiredo ◽  
Paulo S. de Souza
Keyword(s):  
Reference Evapotranspiration ◽  
Irrigation Management ◽  
Climatic Conditions ◽  
Climatic Data ◽  
And Performance ◽  
Crop Coefficients ◽  
The City ◽  
Adequate Management ◽  
Monteith Equation ◽  
Statistical Indicators

Aiming at contributing to an adequate management of water resources, this study aimed to analyze and compare evapotranspiration (ETc) and crop coefficients (Kc) of melon plants measured by a lysimeter and estimated according to the FAO 56 methodology, in the city of Mossoró, state of Rio Grande do Norte (RN), Brazil. In order to measure ETc, weighing lysimeters with an area of 2.25m² were used, with two repetitions. The Penman-Monteith equation parameterized by FAO was used to estimate the reference evapotranspiration, and crop coefficients were those recommended in FAO-56 Bulletin adjusted to local climatic conditions. The required climatic data and lysimeter measurements were collected by an automatic weather station installed at the site. The results were compared by means of statistical indicators: of precision (r), of accuracy (d), and performance (c), in daily and weekly intervals. The data estimated by the FAO 56 methodology were adjusted optimally to the values measured by the lysimeters in accordance with index "c" in the two time scales assessed, indicating the potential of the method proposed by FAO to irrigation management in the climatic conditions of Agripole Assú-Mossoró.

Annual Evapotranspiration and Crop Coefficients of Ligustrum japonica Growing in Three Container Sizes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 512c-512
Author(s):  
R.C. Beeson
Keyword(s):  
Reference Evapotranspiration ◽  
Actual Evapotranspiration ◽  
Rooted Cuttings ◽  
Supplemental Irrigation ◽  
Mean Size ◽  
Crop Coefficients ◽  
Marketable Size

The objective of this study was to determine crop coefficients (KC) for Ligustrum japonica growing in three container sizes using the Penman equation to calculate reference evapotranspiration (ETR). Rooted cuttings were transplanted into 3-liter containers and upcanned as needed into 10- and 23-L containers. Production was scheduled such that a series of plants in each container size were about 2 months from commercial marketable size every 4 months. Beginning 1 Jan. 1995 until 31 Dec. 1996, three uniform plants of each size were suspended in weighing lysimeters and surrounded by similar size plants filling an area 3.7 by 4.9 m. Plants within each area were overhead irrigated at 2000 h as needed, based on a 30% moisture allowed deficit. Plants were exchanged every 4 months such that the annual mean size was that of a marketable plant. Actual evapotranspiration (ETA) was calculated from half-hour measurements of each plant's weight and adjusted for rainfall. From these and daily calculated ETR, KC were determined for each size of container. KCs ranged from 1.06 to 1.50 when ETA was converted to mm/day based on allocated bed space. Comparisons of volumes of supplemental irrigation to ETA and effects of assumptions required in converting ETA to mm/day will be discussed.

scholarly journals The Water Needs of Grapevines in Central Poland

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 416
Author(s):  
Barbara Jagosz ◽  
Stanisław Rolbiecki ◽  
Roman Rolbiecki ◽  
Ariel Łangowski ◽  
Hicran A. Sadan ◽  
...  
Keyword(s):  
Climate Change ◽  
Temporal Variability ◽  
Time Trend ◽  
Reference Evapotranspiration ◽  
Growing Season ◽  
Water Requirements ◽  
Climate Conditions ◽  
Central Poland ◽  
Crop Coefficients ◽  
Near Future

Climate warming increases the water needs of plants. The aim of this study was to estimate the water needs of grapevines in central Poland. Water needs were calculated using the crop coefficients method. Reference evapotranspiration was assessed by the Blaney–Criddle’s equation, modified for climate conditions in Poland. Crop coefficients were assumed according to the Doorenbos and Pruitt method. Water needs were calculated using the data from four meteorological stations. Rainfall deficit with the probability occurrence of normal years, medium dry years, and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the average growing season were estimated at 438 mm. Upward time trend in the water needs both in the period of May–October and June–August was estimated. Temporal variability in the water needs was significant for all of the provinces. These changes were mainly impacted by a significant increasing tendency in mean air temperature and less by precipitation totals that did not show a clear changing tendency. Due to climate change, vineyards will require irrigation in the near future. The use of resource-efficient irrigation requires a precise estimate of the grapevines’ water needs. The study identified the water requirements for grapevines in central Poland.

scholarly journals Calibration of reference evapotranspiration models in Pará

2019 ◽  
Vol 42 ◽  
pp. e42475
Author(s):  
Vivian Dielly da Silva Farias ◽  
Deborah Luciany Pires Costa ◽  
Joao Vitor de Novoa Pinto ◽  
Paulo Jorge Oliveira Ponte de Souza ◽  
Everaldo Barreiro de Souza ◽  
...  
Keyword(s):  
Water Management ◽  
Linear Regression ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Estimation Methods ◽  
Correction Factors ◽  
Regression Methods ◽  
Dry Seasons ◽  
Statistical Criteria

The use of empirical agrometeorological models that can be adjusted to the climatic conditions of different regions has become increasingly necessary to improve water management in grain-producing municipalities. The aim of this work is to examine the correlation between various reference evapotranspiration (ETo) estimation methods and the standard FAO 56 Penman-Monteith method, as well as to determine correction factors, when necessary, for crop-producing municipalities in the northeast of Pará, during both the rainy and dry seasons. We compared simpler methods of ETo estimation to the FAO 56 Penman-Monteith method. For this purpose, meteorological data from Tracuateua, Bragança, Capitão Poço and Castanhal, provided by the National Institute of Meteorology (INMET), were used. The calibration of equations was performed through linear regression. The accuracy of different estimation methods was examined. The Turc, FAO 24 Blaney-Criddle and regression methods presented the best results for all statistical criteria; the Priestley-Taylor, Makkink and FAO 24 Radiation methods presented excellent results after calibration. The methods of Camargo and Hargreaves-Samani produced the worst results for all the criteria.

scholarly journals Performance of methods for estimation of table beet water requirement in Alagoas

2018 ◽  
Vol 22 (3) ◽  
pp. 189-193 ◽  
Author(s):  
Daniella P. dos Santos ◽  
Célia S. dos Santos ◽  
Leiliane M. da Silva ◽  
Márcio A. L. dos Santos ◽  
Cícero G. dos Santos
Keyword(s):  
Water Use ◽  
Standard Method ◽  
Water Scarcity ◽  
Performance Index ◽  
Reference Evapotranspiration ◽  
Irrigation Management ◽  
Crop Evapotranspiration ◽  
Abstract Optimization ◽  
Crop Coefficients ◽  
Drainage Lysimeter

ABSTRACT Optimization of water use in agriculture is fundamental, particularly in regions where water scarcity is intense, requiring the adoption of technologies that promote increased irrigation efficiency. The objective of this study was to evaluate evapotranspiration models and to estimate the crop coefficients of beet grown in a drainage lysimeter in the Agreste region of Alagoas. The experiment was conducted at the Campus of the Federal University of Alagoas - UFAL, in the municipality of Arapiraca, AL, between March and April 2014. Crop evapotranspiration (ETc) was estimated in drainage lysimeters and reference evapotranspiration (ETo) by Penman-Monteith-FAO 56 and Hargreaves-Samani methods. The Hargreaves-Samani method presented a good performance index for ETo estimation compared with the Penman-Monteith-FAO method, indicating that it is adequate for the study area. Beet ETc showed a cumulative demand of 202.11 mm for a cumulative reference evapotranspiration of 152.00 mm. Kc values determined using the Penman-Monteith-FAO 56 and Hargreaves-Samani methods were overestimated, in comparison to the Kc values of the FAO-56 standard method. With the obtained results, it is possible to correct the equations of the methods for the region, allowing for adequate irrigation management.

Comparison between forecasts of reference evapotranspiration and ETo values calculated using data from different climatic conditions

2020 ◽  
Author(s):  
Ghaieth Ben Hamouda ◽  
Francesca Ventura ◽  
Daniele Zaccaria ◽  
Khaled M. Bali ◽  
Richard L. Snyder
Keyword(s):  
Reference Evapotranspiration ◽  
Irrigation Management ◽  
Climatic Conditions ◽  
Physical Models ◽  
Dew Point ◽  
Water Losses ◽  
Plant Canopies ◽  
Crucial Component ◽  
And Performance ◽  
Using Data

<p>Evapotranspiration is the transfer of water from the earth's surface to the atmosphere. It comprises the sum of water losses to atmosphere due to the processes of evaporation of moisture from soil, water bodies and wet plant canopies, and the transpiration of water from plants. Forecasts of this crucial component of the hydrologic cycle can be very valuable for growers, farm managers, irrigation practitioners, water resource planners and managers, and reservoir operators for their planning, allocation, delivery and scheduling decisions, as well as to hydrologic scientists for research purposes. Verifying the reliability of models’ forecasts is among the critical tasks for development and performance evaluation of physical models. In fact, the verification allows understanding the models’ behavior, and evaluating their applicability and dependability. The US National Weather Service (NWS) has released a product that provides forecasts of reference evapotranspiration (FRET) at 2.5-km grid resolution for the entire continental US. In this study, a comparison is made between ETo estimates from FRET and ETo values calculated by the California Irrigation Management Information System (CIMIS) for 68 days during summer 2019. Both the FRET forecasts and ETo values were obtained from NWS and CIMIS, respectively, on the basis of 15 CIMIS locations that are representative of different climatic conditions in California. In addition, air temperature, dew point temperature, relative humidity, wind speed, and vapor pressure deficit (VPD) data were also collected/calculated from the NWS and CIMIS websites to analyze the sensitivity of FRET forecasts to predictions of these parameters. All FRET forecasts were performed with timescales of 1, 3, 5 and 7 days. Statistical indices were calculated to assess the dependability of FRET values. They showed a good correlation of the FRET model outputs with CIMIS ETo data, with some differences depending on the climatic characteristics of selected weather stations’ locations, suggesting that FRET data could be valuable for anticipating near-future water demand and improve irrigation management in California.</p>

scholarly journals Evapotranspiration and crop coefficients of Moringa oleifera under semi-arid conditions in Pernambuco

2017 ◽  
Vol 21 (12) ◽  
pp. 840-845 ◽  
Author(s):  
Célia S. dos Santos ◽  
Abelardo A. de A. Montenegro ◽  
Márcio A. L. dos Santos ◽  
Elvira M. R. Pedrosa
Keyword(s):  
Moringa Oleifera ◽  
Reference Evapotranspiration ◽  
Temporal Variations ◽  
Experimental Unit ◽  
Crop Evapotranspiration ◽  
Water Restriction ◽  
Phenological Stages ◽  
Indirect Methods ◽  
Crop Coefficients ◽  
Semi Arid

ABSTRACT Efficient water use in agriculture is fundamental, especially in semi-arid regions where water scarcity is intense. The aim of this study was to estimate water requirements and crop coefficients in the different phenological stages of Moringa oleifera. The experiment was carried out from February to April 2015 at the Experimental Unit for Reuse and Hydrological Management, located in Mutuca, PE (7º 15’ 18’’ S, 35º 52’’ 40’’ W, 550 m). A lysimeter was used to estimate crop evapotranspiration. Reference evapotranspiration (ETo) was estimated by indirect methods. In the lysimeter, soil salinity and leaf water potential of the crop were monitored. The direct and indirect methods presented an excellent performance compared with the standard grass-lysimeter, especially Hargreaves-Samani, which presented a remarkable result for the study area. Crop coefficients (Kc) ranged from 0.73 to 1.73 in the different phenological stages. Moringa crop evapotranspiration (ETc) exhibited temporal variations, with a cumulative rate of 139.8 mm, for a cumulative reference evapotranspiration of 130.97 mm. Moringa plants showed slight water restriction, at the times of lower solar radiation.

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