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 ◽  
...  

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.

Időjárás ◽  
2021 ◽  
Vol 125 (3) ◽  
pp. 419-430
Author(s):  
Angela Anda ◽  
László Menyhárt ◽  
Brigitta Simon

Evapotranspiration rate, ETaand vegetation composition strongly influence the water budget of wetland impacting available water and water resource management. One of the goals of this study was to estimate the areal ETa of the Kis-Balaton wetland, KBW (natural ecosystem) between 1997 and 2012. This time period was free of any human intervention. ETa was accounted for different vegetation classes through the multiplication of the reference evapotranspiration, ET0 by previously determined crop coefficients in each vegetation/open water classes. Besides common reed and cattail, five other groups were separated, including open water as an independent class. The evapotranspiration sums were strongly impacted by annual mean air temperature, Ta. One degree increment in annual average Ta will increase the yearly ETa sums in about 100 mm. The yearly areal ETaof KBW ranged from 737.08 mm to 896.63 mm with an average of 802.07 mm during the 16-year study.


2020 ◽  
Vol 69 (2) ◽  
pp. 15-25
Author(s):  
Borivoj Pejić ◽  
Ksenija Mačkić ◽  
Ivana Bajić ◽  
Vladimir Sikora ◽  
Dejan Simić ◽  
...  

Analysis of irrigation scheduling of maize was done by using evaporation from the free water surface (Eo) and correction coefficients (k) and reference evapotranspiration (ETo) and crop coefficients (kc). The field experiment was carried out in 2018 on the Experimental field of the Institute of field and vegetable crops in the Department of alternative crops in Bački Petrovac. Maize hybrid NS 6030 was used for the trials. The plants were irrigated by a drip system with a lateral in each row with drippers spaced every 0.33 m. The drippers had an average flow rate of 2.0 l h-1 under the pressure of 70 kPa. The differences in yield of maize in the irrigation conditions were not statistically significant compared to the variant without irrigation because the year was favorable for maize production. As well there was no difference among variants used for the calculation of maize evapotranspiration. Maize evapotranspiration in the growing season (ETm) were 502 mm and 429 mm by using ETo and kc and Eo and k. Monthly values of ETm during the growing season were consistent regardless of the calculation methods, except in July. Values of ETm in July of 151 mm and 107 mm calculated by using ETo and kc and Eo and k methods as well the daily values which are correlated with the monthly have to be checked in irrigation scheduling of maize in the following investigation period. If statistical significance in maize yield between different methods of calculation is determined, the procedure with a higher yield has to be accepted in the calculation of ETm in the climatic conditions of the Vojvodina region. Otherwise, if the differences in maize yield are not statistical significance a method of calculation by using Eo and k will be recommended, because the value of the lower daily water used on maize evapotranspiration may be considered more realistic.


2021 ◽  
Vol 282 ◽  
pp. 05008
Author(s):  
S.A. Kurbanov ◽  
M.M. Dzhambulatov ◽  
V.V. Borodychev ◽  
D.S. Magomedova

The paper presents the materials of field research on the study of the regularities of the development of moisture outlines on light soils during drip irrigation of vegetable crops. The correlation is found between the depth of the moistened layer and the area of the moistening outlines on the pre-irrigation threshold of the moisture content of the active soil layer, irrigation standards and the flow rate of drippers, which gives an opportunity to decline the unproductive water consumption for filtration. It is found that in light loamy and sandy loam light chestnut soils, for guaranteed rule of the moisture regime, on onion crops, it is essential to maintain the pre-irrigation threshold of 80% HB with the irrigation rate of 200 m3 / ha with the flow rate of drip water outlets of 2.8 l / h, and the depth of irrigation of 120 m3/ha with the flow rate of discharge outlets of 1.7 l/h, correspondingly. In irrigation of tomatoes grown on light-loamy light-chestnut soils, it is appropriate to apply the irrigation rate of 180 m3 / ha, which provides the level of pre-irrigation humidity in the layer of 0.6 m not lower than 80% HB, the formation of the required characteristics of the moisture contour (depth of 0.62 m and diameter of 0.37 m), as well as an enhance in the efficiency of irrigation water use by 11.1%. The results can be applied in the design of drip irrigation systems for vegetable crops.


2018 ◽  
Vol 50 (1) ◽  
pp. 282-300 ◽  
Author(s):  
Hadi Farzanpour ◽  
Jalal Shiri ◽  
Ali Ashraf Sadraddini ◽  
Slavisa Trajkovic

Abstract Accurate estimation of reference evapotranspiration (ETo) is a major task in hydrology, water resources management, irrigation scheduling and determining crop water requirement. There are many empirical equations suggested by numerous references in literature for calculating ETo using meteorological data. Some such equations have been developed for specific climatic conditions while some have been applied universally. The potential for usage of these equations depends on the availability of necessary meteorological parameters for calculating ETo in different climate conditions. The focus of the present study was a global cross-comparison of 20 ETo estimation equations using daily meteorological records of 10 weather stations (covering a period of 12 years) in a semi-arid region of Iran. Two data management scenarios, namely local and cross-station scenarios, were adopted for calibrating the applied equations against the standard FAO56-PM model. The obtained results revealed that the cross-station calibration might be a good alternative for local calibration of the ETo models when proper similar stations are used for feeding the calibration matrix.


Horticulturae ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 49 ◽  
Author(s):  
Matthias Olberz ◽  
Katrin Kahlen ◽  
Jana Zinkernagel

Reference evapotranspiration (E T 0) is a major estimator for crop water requirements predicted by decision support systems for irrigation. However, the impact of different E T 0s on the predicted amount of water supply and counts of irrigation events has not been evaluated. Simulations of the Geisenheim Irrigation Scheduling (GS) for vegetable crops with two different E T 0s, P2-E T 0 and FAO56-E T 0, were evaluated to assess exemplarily the impact of E T 0s. The sensitivity of both E T 0s to local climate conditions was characterized through a random forest analysis, and a linear regression model was used to adjust the original GS by adapting K c-values to the exchange E T 0. For assessing the outcomes of GS irrigation decision, simulations of 173 individual cropping cycles including six vegetable crops over eight years were conducted. After adjusting P2-E T 0 K c-values to FAO56-E T 0 K c-values, there was no impact of the E T 0-model on the practical irrigation scheduling with GS. Finally, we discuss that any E T 0-model, if adjusted accordingly, might have little impact on similar irrigation systems and provide a method to exchange E T 0s.


2021 ◽  
Vol 58 (1) ◽  
pp. 62-72
Author(s):  
J Ramachandran ◽  
R Lalitha ◽  
S. Vallal Kannan

Crop coefficient (Kc ) is an important parameter in estimating the crop water requirements during different crop growth stages. The Kc values for a particular crop are highly site and region-specific and need to be precisely determined for each agro-climatic region for better irrigation scheduling and improved water and crop productivity. The site-specific crop coefficients for paddy, sugarcane, and banana cultivated in Lalgudi block, Tiruchirapalli District, Tamil Nadu, India, were estimated using two remote sensing-based methods viz. NDVI-Kc linear regression technique and SEBAL actual evapotranspiration to reference evapotranspiration ratio approach (SEBAL-Kc ). The Kc values obtained by remote sensing methods were compared with FAO-56 Adjusted Kc (ClimAdj-Kc ) for local climatic conditions and FAO-56 tabulated reference Kc values (FAOTab-Kc ). Regression analysis revealed a good agreement between NDVI-Kc and ClimAdj-Kc for paddy (R2 =0.95), banana (R2 =0.93), and sugarcane (R2 =0.79). Compared to FAO56-Kc, the derived Kc values using NDVI-Kc were higher, while the SEBAL-Kc values were lower for all growth stages of paddy. For sugarcane crops, the FAO-56 Kc, NDVI-Kc, and ClimAdj-Kc for local climate were almost similar in all stages. In the case of bananas, NDVI-Kc and SEBAL-Kc were higher as compared to the FAO-56-Kc and ClimAdj-Kc. SEBAL approach performs well as it accounted for local climatic conditions and crop canopy changes, whereas NDVI considered only crop canopy. However, the SEBAL method is computationally intensive as compared to the NDVI-Kc method. The Kc values estimated in this study can be important in quantifying the crop evapotranspiration at regional and field scales, leading to better decision-making in irrigation scheduling.


Author(s):  
Jesús Enrique Chavarría Párraga ◽  
Julio Cesar Ramírez-Caicedo ◽  
Jorge Isaac Zambrano-Kuffó ◽  
Richard Xavier Bravo-Ferrín ◽  
Luis Enrique Párraga-Muñoz

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.


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

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.


2021 ◽  
Vol 22 (2) ◽  
pp. 172-178
Author(s):  
ABHIJIT SARMA ◽  
KRISHNA BHARADWAJ

Accurate estimation of evapotranspiration of rapeseed is essentially required for irrigation scheduling and water management. The present study was undertaken during 2015-16 and 2017-18 in ICR Farm, Assam Agricultural University, Jorhat to determine the crop coefficients (Kc) and estimate evapotranspiration of rapeseed using lysimeter and eight reference evapotranspiration models viz. Penman-Monteith, Advection-Aridity (Bruitsaert-Strickler), Granger-Gray, Makkink, Blaney-Criddle, Turc (1961), Hargreaves-Somani and Priestly-Tailor models. During 2015-16, the crop coefficients were developed by these models. Actual evapotranspiration was determined by three weighing type lysimeters. During 2017-18, evapotranspiration was estimated by multiplying reference evapotranspiration with Kc derived by different models and compared with actual evapotranspiration estimated by lysimeter during similar growing periods. All the models except Turc (1961) showed less than 10% deviation between actual and estimated ET. The estimated evapotranspiration using Penman-Monteith and Priestly-Tailor reference evapotranspiration recorded the lowest MAE and RMSE. The study revealed that estimated evapotranspiration using Penman-Monteith reference evapotranspiration gave the best estimate of evapotranspiration of rapeseed followed by Priestly-Tailor. The crop coefficients for initial, mid and end stages were 0.83, 1.20 and 0.65, respectively for Penman-Monteith and 0.70, 1.05 and 0.55, respectively for Priestly-Tailor.These results can be used for efficient management of irrigation water for rapeseed.


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