Water requirements of olive orchards–II: determination of crop coefficients for irrigation scheduling

2005 ◽  
Vol 24 (2) ◽  
pp. 77-84 ◽  
Author(s):  
F. Orgaz ◽  
L. Testi ◽  
F.J. Villalobos ◽  
E. Fereres
Keyword(s):  
Irrigation Scheduling ◽  
Water Requirements ◽  
Crop Coefficients

Weighing Lysimeters for the Determination of Crop Water Requirements and Crop Coefficients

2006 ◽  
Vol 22 (6) ◽  
pp. 851-856 ◽  
Author(s):  
T. Marek ◽  
G. Piccinni ◽  
A. Schneider ◽  
T. Howell ◽  
M. Jett ◽  
...  
Keyword(s):  
Crop Water ◽  
Water Requirements ◽  
Crop Water Requirements ◽  
Crop Coefficients

scholarly journals Determination of crop-coefficients and estimation of evapotranspiration of rapeseed using lysimeter and different reference evapotranspiration models

2021 ◽  
Vol 22 (2) ◽  
pp. 172-178
Author(s):  
ABHIJIT SARMA ◽  
KRISHNA BHARADWAJ
Keyword(s):  
Water Management ◽  
Irrigation Water ◽  
Reference Evapotranspiration ◽  
Irrigation Scheduling ◽  
Actual Evapotranspiration ◽  
Accurate Estimation ◽  
Efficient Management ◽  
Best Estimate ◽  
Crop Coefficients

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.

Irrigation scheduling and water requirements for cowpea using evaporation pan at middle of Iraq

1970 ◽  
pp. 13-17
Author(s):  
Saifuldeen A. Salim ◽  
Isam Kudhier Hamza ◽  
Laith Farhan Jar
Keyword(s):  
Water Productivity ◽  
Irrigation Treatment ◽  
Growing Season ◽  
Irrigation Scheduling ◽  
Water Requirements ◽  
Applied Water ◽  
Fresh Seed ◽  
Irrigation Interval ◽  
Biological Yield ◽  
Evaporation Pan

The present study was conducted to find out the water requirements and most suitable irrigation frequencies for cowpea (Vigna unguiculata L.) var grown under drip irrigation. The treatments were based on the IW:CPE ratio at different empirical pan factors 0.6 , 0.8, 1.0, 1.,1.4 , and 1.6 Ef (where Ef = IW/CPE). It was observed that the irrigation interval was variable values decreased by increasing Ef value and with the progress of the growing season. The 1.2 and 1.0 IW: CPE treatments with approximately 4 days irrigation interval were achieved the best results. The total amount of applied water during Cowpea growing season was varied between 247.7 and 266.5mm with 254.8mm as a mean. Irrigation treatment with Ef1.2 was superior over the rest of other treatments in fresh seed yield (5.13 ton.hec.-1), crop water productivity (2.14 kg.m-3), biological yield (6.88 ton.hec.-1) , fresh pod yield (7.33 ton.hec.-1), weight of 100 seed (31.28gm), number of seed/pod (9.34) and netting percentage (37.1). The lowest values of the most parameters used in this study were obtained by Ef 0.6 irrigation treatment.  

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 Study of Dual Stator Induction Motor in Photovoltaic-Fuel Cell Hybrid Pumping Application

2020 ◽  
Vol 53 (5) ◽  
pp. 601-608
Author(s):  
Arezki Adjati ◽  
Toufik Rekioua ◽  
Djamila Rekioua ◽  
Abdelmounaim Tounzi
Keyword(s):  
Fuel Cell ◽  
Induction Motor ◽  
Centrifugal Pump ◽  
Cell Hybrid ◽  
Double Star ◽  
Water Requirements ◽  
Matlab Simulink ◽  
Pumping System ◽  
Dynamic Head

This paper discusses the modeling of hybrid Photovoltaic/Fuel cell pumping. This system comprises a photovoltaic generator and a fuel cell, two DC/DC converters, two of inverters which supply a double star induction motor (DSIM) which drives the shaft of a centrifugal pump. The evaluation of the water requirements, the total dynamic head (TDH) and the flow are of great importance to evaluate the various powers allowing the determination of the size of the pumping system. The global proposed system is sized and simulated under Matlab/Simulink Package. The obtained results under different metrological conditions show the effectiveness of the proposed hybrid pumping system.

scholarly journals Optimization of irrigation water in South Africa for sustainable and beneficial use

2017 ◽  
Author(s):  
◽  
Akinola Mayowa Ikudayisi
Keyword(s):  
South Africa ◽  
Water Use ◽  
Crop Yield ◽  
Optimization Algorithm ◽  
Irrigation Water ◽  
Irrigation Scheduling ◽  
Crop Water ◽  
Land Area ◽  
Water Requirements ◽  
Irrigation Water Use

Water is an essential natural resource for human existence and survival on the earth. South Africa, a water stressed country, allocates a high percentage of its available consumptive water use to irrigation. Therefore, it is necessary that we optimize water use in order to enhance food security. This study presents the development of mathematical models for irrigation scheduling of crops, optimal irrigation water release and crop yields in Vaal Harts irrigation scheme (VIS) of South Africa. For efficient irrigation water management, an accurate estimation of reference evapotranspiration (ETₒ) should be carried out. However, due to non-availability of enough historical data for the study area, mathematical models were developed to estimate ETₒ. A 20-year monthly meteorological data was collected and analysed using two data–driven modeling techniques namely principal component analysis (PCA) and adaptive neuro-fuzzy inference systems (ANFIS). Furthermore, an artificial neural network (ANN) model was developed for real time prediction of future ETₒ for the study area. The real time irrigation scheduling of potatoes was developed using a crop growth simulation model called CROPWAT. It was used to determine the crop water productivity (CWP), which is a determinant of the relationship between water applied and crop yield. Finally, a new and novel evolutionary multi-objective optimization algorithm called combined Pareto multi-objective differential evolution (CPMDE) was applied to optimize irrigation water use and crop yield on the VIS farmland. The net irrigation benefit, land area and irrigation water use of maize, potatoes and groundnut were optimized. Results obtained show that ETₒ increases with temperature and windspeed. Other variables such as rainfall and relative humidity have less significance on the value of ETₒ. Also, ANN models with one hidden layer showed better predictive performance compared with other considered configurations. A 5-day time step irrigation schedule data and graphs showing the crop water requirements and irrigation water requirements was generated. This would enable farmers know when, where, and how much water to apply to a given farmland. Finally, the employed CPMDE optimization algorithm produced a set of non-dominated Pareto optimal solutions. The best solution suggests that maize, groundnut and potatoes should be planted on 403543.44 m2, 181542.00 m2 and 352876.05 m2areas of land respectively. This solution generates a total net benefit of ZAR 767,961.49, total planting area of 937961.49 m2 and irrigation water volume of 391,061.52 m3. Among the three crops optimized, maize has the greatest land area, followed by potatoes and groundnut. This shows that maize is more profitable than potatoes and groundnut with respect to crop yield and water use in the study area.

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