scholarly journals Transpiration and Water Use of an Irrigated Traditional Olive Grove with Sap-Flow Observations and the FAO56 Dual Crop Coefficient Approach

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2466
Author(s):  
Àngela Puig-Sirera ◽  
Giovanni Rallo ◽  
Paula Paredes ◽  
Teresa A. Paço ◽  
Mario Minacapilli ◽  
...  
Keyword(s):  
Water Balance ◽  
Water Use ◽  
Sap Flow ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Soil Evaporation ◽  
Olive Grove ◽  
Crop Evapotranspiration ◽  
Tree Transpiration ◽  
Mean Square Errors

The SIMDualKc model was applied to evaluate the crop water use and the crop coefficient (Kc) of an irrigated olive grove (Olea europaea L.) located in Sicily, Italy, using experimental data collected from two crop seasons. The model applies the FAO56 dual Kc approach to compute the actual crop evapotranspiration (ETc act) and its components, i.e., the actual tree transpiration (Tc act), obtained through the basal crop coefficient (Kcb), and soil evaporation according to an evaporation coefficient (Ke). Model calibration was performed by minimizing the difference between the predicted Tc act and the observed daily tree transpiration measured with sap flow instrumentation (TSF field) acquired in 2009. The validation was performed using the independent data set of sap flow measurements from 2011. The calibrated Kcb was equal to 0.30 for the initial and non-growing season stages, 0.42 for the mid-season, and 0.37 for the end season. For both seasons, the goodness-of-fit indicators relative to comparing TSF field with the simulated Tc act resulted in root mean square errors (RMSE) lower than 0.27 mm d−1 and a slope of the linear regression close to 1.0 (0.94 ≤ b0 ≤ 1.00). The olive grove water balance simulated with SIMDualKc produced a ratio between soil evaporation (Es) and ETc act that averaged 39%. The ratio between actual (ETc act) and potential crop evapotranspiration (ETc) varied from 84% to about 99% in the mid-season, indicating that the values of ETc act are close to ETc, i.e., the adopted deficit irrigation led to limited water stress. The results confirm the suitability of the SIMDualKc model to apply the FAO56 dual Kc approach to tree crops, thus assessing the water use of olives and supporting the development of appropriate irrigation management tools that are usable by farmers. A different way to estimate Kcb is based on the approach suggested in 2009 by Allen and Pereira (A&P), which involves the measured fraction of ground covered (shaded) by the crop and the height of the trees. Its application to the studied grove produced the mid-season Kcb values ranging from 0.40–0.45 and end-season Kcb values ranging from 0.35–0.40. The comparison between the A&P-computed Tc act A&P and TSF field shows RMSE values ranging from 0.27 to 0.43 mm d−1, which demonstrates the adequacy of the latter approach for parameterizing water balance models and for irrigation scheduling decision making.

scholarly journals Evaluation of a Hybrid Reflectance-Based Crop Coefficient and Energy Balance Evapotranspiration Model for Irrigation Management

2018 ◽  
Vol 61 (2) ◽  
pp. 533-548 ◽  
Author(s):  
J. Burdette Barker ◽  
Christopher M. U. Neale ◽  
Derek M. Heeren ◽  
Andrew E. Suyker
Keyword(s):  
Remote Sensing ◽  
Energy Balance ◽  
Water Balance ◽  
Real Time ◽  
Eddy Covariance ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Crop Coefficients

Abstract. Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (Kcbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the Penman-Monteith (PM) approximation for comparison. We compared energy balance fluxes and computed ET with measurements from three eddy covariance systems within the study area. Net radiation was underestimated by the model when data from a local weather station were used as input, with mean bias error (MBE) of -33.8 to -40.9 W m-2. The measured incident solar radiation appeared to be biased low. The net radiation model performed more satisfactorily when data from the eddy covariance flux towers were input into the model, with MBE of 5.3 to 11.2 W m-2. We removed bias in the daily energy balance ET using a dimensionless multiplier that ranged from 0.89 to 0.99. The bias-corrected TSEB ET, using weather data from a local weather station and with local ground data in thermal infrared imagery corrections, had MBE = 0.09 mm d-1 (RMSE = 1.49 mm d-1) for PM and MBE = 0.04 mm d-1 (RMSE = 1.18 mm d-1) for PT. The hybrid model used statistical interpolation to combine the two ET estimates. We computed weighting factors for statistical interpolation to be 0.37 to 0.50 for the PM method and 0.56 to 0.64 for the PT method. Provisions were added to the model, including a real-time crop coefficient methodology, which allowed seasonal crop coefficients to be computed with relatively few remote sensing images. This methodology performed well when compared to basal crop coefficients computed using a full season of input imagery. Water balance ET compared favorably with the eddy covariance data after incorporating the TSEB ET. For a validation dataset, the magnitude of MBE decreased from -0.86 mm d-1 (RMSE = 1.37 mm d-1) for the Kcbrf alone to -0.45 mm d-1 (RMSE = 0.98 mm d-1) and -0.39 mm d-1 (RMSE = 0.95 mm d-1) with incorporation of the TSEB ET using the PM and PT methods, respectively. However, the magnitudes of MBE and RMSE were increased for a running average of daily computations in the full May-October periods. The hybrid model did not necessarily result in improved model performance. However, the water balance model is adaptable for real-time irrigation scheduling and may be combined with forecasted reference ET, although the low temporal frequency of satellite imagery is expected to be a challenge in real-time irrigation management. Keywords: Center-pivot irrigation, ET estimation methods, Evapotranspiration, Irrigation scheduling, Irrigation water balance, Model validation, Variable-rate irrigation.

Influence of tree transpiration on mass water balance of mixed mountain forests of the West Carpathians

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Katarína Střelcová ◽  
Jozef Minďáš ◽  
Jaroslav Škvarenina
Keyword(s):  
Water Balance ◽  
Forest Ecosystem ◽  
Sap Flow ◽  
Potential Evapotranspiration ◽  
Biosphere Reserve ◽  
Flow Measurements ◽  
Tree Transpiration ◽  
Precipitation Total ◽  
Beech Stand ◽  
Snow Precipitation

AbstractBrief information about water balance of the Carpathian temperate forest ecosystem are presented in the paper. Experimental research was done in a mature mixed fir-spruce-beech stand in the research plot “Pol’ana-Hukavský grúň” (850 m a.s.l.) in the south-eastern part of Pol’ana Mts. in the Biosphere Reserve UNESCO in Central Slovakia. Individual parameters of water budget have been continuously monitored. The water consumption of the model beech trees, as well as approximate model beech stand transpiration was estimated on the basis of sap flow measurements and up-scaling through dendrometrical approach. Sap flow of model beech trees was estimated by direct, non-destructive and continuous measurements by tree-trunk heat balance method with internal heating and sensing of temperature. These values were compared with potential evapotranspiration according to Türc. Precipitation parameters (rain and snow precipitation, through-fall precipitation, stem-flow, fog/snow precipitation and infiltration) have been measured simultaneously. Results of mass water balance and the portion of the tree transpiration within the individual water flows are presented. Evapotranspiration of beech-fir forest ecosystem in the middle mountain region (850 m a.s.l.) includes: transpiration (35% of precipitation total), interception (21%), evaporation (8%). There are differences between tree species in mass of transpirated water. Transpiration of spruce and fir reaches two-thirds of beech transpiration. Fog precipitation contribution to the water balance of beech-fir stand is 5%. Concurrently fog precipitation lowers the interception losses of vertical precipitation.

Combining the FAO56 agrohydrological model and remote sensing data to assess water demand in a Sicilian irrigation district

2020 ◽  
Author(s):  
Matteo Ippolito ◽  
Mario Minacapilli ◽  
Giuseppe Provenzano
Keyword(s):  
Remote Sensing ◽  
Water Balance ◽  
Water Use ◽  
Irrigation Water ◽  
Remote Sensing Data ◽  
Irrigation Scheduling ◽  
Irrigation District ◽  
Sensing Data ◽  
Spatiotemporal Distributions ◽  
Crop Parameters

<p>Agricultural water use in irrigated areas plays a key role in the Mediterranean regions characterized by semi-arid climate and water shortage. In the face of optimizing irrigation water use, farmers must revise their irrigation practices to increase the drought resilience of agricultural systems and to avoid severe damages in agro-ecosystems. In this direction, during the last decades, the research has been focused on mathematical models to simulate the process of driving mass transport and energy exchanges in the Soil-Plant-Atmosphere system.</p><p>The objective of the paper was to test the suitability of the combination of FAO56 agro-hydrological model with remote sensing data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) platform, to assess the spatiotemporal distributions of crop water requirement and to schedule irrigation in an irrigation district of the south-west of Sicily, Italy.</p><p>The proposed approach allowed obtaining the spatiotemporal distributions of soil and crop parameters used in the FAO56 model implemented in a GIS environment to simulate the water balance, as well as to assess the actual irrigation strategy. The GIS database was organized to include soil and crop parameters, as well as the irrigation volumes actually delivered to each farmer; the latter data can be used not only as input for water balance to evaluate the efficiency of the actual irrigation strategies but also to identify different irrigation scheduling scenario obtained by the FAO56 procedure.</p><p>The first application was carried out for the period 2014-2017, to identify a combination of irrigation scheduling parameters to be implemented in the model aimed at reproducing the ordinary strategy adopted by the farmers, based on the spatiotemporal variability of soil and climate forcings. When the model outputs were aggregated for single crop types, a fairly good agreement was found between simulated and actual seasonal irrigation volumes delivered either at the level of district and secondary units. Alternative scenarios of irrigation water distribution were then identified and analyzed, to provide irrigation technicians and policymakers a decision support tool to improve the efficiency of irrigation systems and to optimize the distribution based on the availability of water resources.</p>

scholarly journals Actual evapotranspiration and crop coefficient of sweet orange during the initial development phase in the Rio Largo region, Alagoas

2019 ◽  
Vol 49 (6) ◽  
Author(s):  
Ricardo Barros Silva ◽  
José Leonaldo de Souza ◽  
Ricardo Araújo Ferreira Júnior ◽  
Marcos Alex dos Santos ◽  
Renan Cantalice de Souza ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Inverse Modeling ◽  
Sweet Orange ◽  
Crop Coefficient ◽  
Time Domain Reflectometry ◽  
Soil Water Balance ◽  
Crop Evapotranspiration ◽  
Initial Development ◽  
Water Balances

ABSTRACT: Determining actual crop evapotranspiration (ETa) is paramount for irrigation management. The principal measurement methods and physical models generally require crop and weather data that are not readily available. We determined the crop coefficient (Kc) of sweet oranges during the initial development stage and evaluated the performance of the Poulovassilis semi-empirical model coupled with a simple soil water balance for estimating the ETa. The ETa was inferred from the variation in the soil water content over time, measured by time-domain reflectometry. In the Poulovassilis model, the ETa is obtained by multiplying the crop evapotranspiration (ETc) by an adjustment coefficient (ca), which accounts for a reduction in the evapotranspiration caused by soil water depletion. Soil water storage was obtained using the daily and 10-day soil water balances, computed by considering inputs and outputs of water from the system. The empirical parameter, ca, was determined using inverse modeling. The optimal ca value obtained through inverse modeling was 0.05 and 0.03 for the daily and 10-day soil water balances, respectively. The model performed better for the daily soil water balance than the 10-day balance, with performance comparable with the other ETa models. Average Kc during the sweet orange initial crop stage was 0.85.

scholarly journals Crop Coefficients and Transpiration of a Super Intensive Arbequina Olive Orchard using the Dual Kc Approach and the Kcb Computation with the Fraction of Ground Cover and Height

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 383 ◽  
Author(s):  
Teresa Paço ◽  
Paula Paredes ◽  
Luis Pereira ◽  
José Silvestre ◽  
Francisco Santos
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Ground Cover ◽  
Soil Water Balance ◽  
Crop Evapotranspiration ◽  
Crop Water ◽  
Water Requirements ◽  
Olive Orchard

The SIMDualKc model was used to simulate crop water requirements for a super high density olive orchard in the region of Alentejo, Portugal. This model uses the dual crop coefficient approach to estimate and partitioning the actual crop evapotranspiration (ETc act) and therefore to perform the soil water balance. The model was calibrated with 2011 tree transpiration using trunk sap flow measurements and was validated using similar data from 2012 and tested with 2013 data. Low root mean square errors (RMSE < 0.53 mm·d−1) and acceptable modelling efficiency indicators (EF > 0.25) were obtained. Further validation was performed comparing modelled ETc act with eddy covariance measurements. These indicators support the appropriateness of using SIMDualKc to guide irrigation management. The basal crop coefficient (Kcb) curves obtained with SIMDualKc for those 3 years were compared with the Kcb values computed with the Allen and Pereira approach (A&P approach) where Kcb is estimated from the fraction of ground cover and plant height considering an adjustment factor for crop stomatal control (Fr). Fr values were obtained through a trial and error procedure through comparing the Kcb estimated with this approach and with SIMDualKc. The Kcb curves obtained by both methods resulted highly correlated, which indicates that the A&P approach may be used in the irrigation management practice to estimate crop water requirements. Results of performing the soil water balance with SIMDualKc have shown that soil evaporation is a large fraction of ETc act, varying between 41% and 45% for the 3 years under study. Irrigation, applied with a drip system, represented 39 to 56% of ETc act, which shows the great importance of irrigation to achieve the water requirements of super intensive olive orchards. Nevertheless, the analysis has shown that the irrigation management adopted at the orchard produces a water deficit larger than desirable, with a ratio of ETc act to non-stressed crop evapotranspiration (ETc) varying from 70% to 94% during the mid-season, when that ratio for a eustress irrigation management could be around 90%.

scholarly journals Performance of arugula genotypes under irrigation depths on Brazilian Cerrado

2018 ◽  
Vol 42 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Fernando França da Cunha ◽  
Ivan Pereira de Souza ◽  
Washington de Oliveira Campos ◽  
Valter Carvalho de Andrade Júnior ◽  
Thiago Alves Magalhães ◽  
...  
Keyword(s):  
Water Balance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Index Number ◽  
Root Depth ◽  
Brazilian Cerrado ◽  
Crop Evapotranspiration ◽  
Irrigation Depth ◽  
Use Efficiency ◽  
Shoot Mass

ABSTRACT Due to the water balance in the Brazilian Cerrado, it is not necessary to cultivate arugula in a rainfed system. Together with the lack of research on with this crop, it is necessary to study the response of genotypes to irrigation in this biome. Thus, the objective of this study was to determine the optimal irrigation depth and to identify the best arugula genotypes. Three arugula genotypes were field-tested during two cycles under the effect of four irrigation depths based on crop evapotranspiration. The parameters evaluated were root depth, SPAD index, number of plants and leaves per plant, plant diameter, fresh shoot mass and water use efficiency. The arugula presented the same demand for irrigation in the two cycles, and the genotypes and/or irrigation depths affected the evaluated parameters. The results support that the Folha Larga variety should be preferred by Brazilian Cerrado producers and irrigated with 90% replacement of crop evapotranspiration.

scholarly journals Test of a microlysimeter for measurement of soil evaporation

2012 ◽  
Vol 32 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Danilton L. Flumignan ◽  
Rogério T. de Faria ◽  
Bruno P. Lena
Keyword(s):  
Water Balance ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Soil Surface ◽  
Bare Soil ◽  
Soil Evaporation ◽  
Soil Water Balance ◽  
Use Efficiency ◽  
Inner Diameter

Quantifying soil evaporation is required on studies of soil water balance and applications aiming to improve water use efficiency by crops. The performance of a microlysimeter (ML) to measure soil evaporation under irrigation and non-irrigation was evaluated. The MLs were constructed using PVC tubes, with dimensions of 100 mm inner diameter, 150 mm depth and 2.5 mm wall thickness. Four MLs were uniformly distributed on the soil surface of two weighing lysimeters conducted under bare soil, previously installed at Iapar, in Londrina, PR, Brazil. The lysimeters had 1.4 m width, 1.9 m length and 1.3 m depth and were conducted with and without irrigation. Evaporation measurements by MLs (E ML) were compared with measurements by lysimeters (E L) during four different periods in the year. Differences between E ML and E L were small either for low or high atmospheric demand and also for either irrigated or non-irrigated conditions, which indicates that the ML tested here is suitable for measurement of soil evaporation.

scholarly journals Lysimeter-Based Water Use and Crop Coefficient of Drip-Irrigated Potato in an Arid Environment

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 756 ◽  
Author(s):  
Alataway ◽  
Al-Ghobari ◽  
Mohammad ◽  
Dewidar
Keyword(s):  
Water Use ◽  
Irrigation Schedule ◽  
Crop Coefficient ◽  
Arid Environment ◽  
Crop Evapotranspiration ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Use Efficiency ◽  
Monteith Equation

The determination of the water requirements and crop coefficient (Kc) of agricultural crops helps to create an appropriate irrigation schedule, and with the effective management of irrigation water. The aim of this research was to estimate the water requirement, Kc, and water-use efficiency (WUE) of potato using non-weighing-type lysimeters in four regions of the Kingdom of Saudi Arabia (Qassiem, Riyadh, Al-Jouf, and Eastern). Our results clearly show that the accumulated values of the measured crop evapotranspiration of potato derived from the lysimeters were 573, 554, 592, and 570 mm, while the accumulated values of the predicted crop evapotranspiration from Penman-Monteith equation based on FAO (Food and Agriculture Organization) were 651, 632, 672, and 647 mm for the Qassiem, Riyadh, Al-Jouf, and Eastern regions, respectively. The Kc values of potato obtained from the lysimeters were Kc initial (0.58, 0.54, 0.50, and 0.52), Kc middle (1.02, 1.05, 1.13, and 1.10), and Kc end (0.73, 0.74, 0.74, and 0.75) for the Qassiem, Riyadh, Al-Jouf, and Eastern regions, respectively. Based on the amount of water used and the yield achieved, the highest WUE (3.6 kg m−3) was observed in the Riyadh region, while the lowest WUE (1.5 kg m−3) was observed in the Al-Jouf region.

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