scholarly journals Sugar cane crop coefficient by the soil water balance method

2015 ◽  
Vol 10 (24) ◽  
pp. 2407-2414 ◽  
Author(s):  
Greco de Guimaraes Cardoso Gabriel ◽  
Campos de Oliveira Renato ◽  
Batista Teixeira Marconi ◽  
Sergio Dorneles Milton ◽  
Marcos Oliveira Domingos Romenig ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Sugar Cane ◽  
Crop Coefficient ◽  
Balance Method ◽  
Soil Water Balance ◽  
Water Balance Method

scholarly journals Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

2016 ◽  
Vol 13 (1) ◽  
pp. 63-75 ◽  
Author(s):  
K. Imukova ◽  
J. Ingwersen ◽  
M. Hevart ◽  
T. Streck
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Winter Wheat ◽  
Water Content ◽  
Soil Water ◽  
Water Storage ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Water Balance Method ◽  
Closure Method

Abstract. The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. In the present study we cross-checked the evapotranspiration data obtained with the EC method (ETEC) against ET rates measured with the soil water balance method (ETWB) at winter wheat stands in southwest Germany. During the growing seasons 2012 and 2013, we continuously measured, in a half-hourly resolution, latent heat (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. ETWB was estimated based on rainfall, seepage and soil water storage measurements. The soil water storage term was determined at sixteen locations within the footprint of an EC station, by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was additionally continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 growing season, the H post-closed LE flux data (ETEC =  3.4 ± 0.6 mm day−1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day−1). ETEC adjusted by the BR (4.1 ± 0.6 mm day−1) or LE (4.9 ± 0.9 mm day−1) post-closure method were higher than the ETWB by 24 and 48 %, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 46 and 70 %, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most observation periods on our site, LE is not a major component of the energy balance gap. Our results indicate that the energy balance gap is made up by other energy fluxes and unconsidered or biased energy storage terms.

scholarly journals Validation of Crop Coefficients and Water Requirement of Maize Crop in the Temperate Climatic Region of India

2020 ◽  
Vol 8 (5) ◽  
pp. 5132-5138
Keyword(s):  
Water Balance ◽  
Reference Evapotranspiration ◽  
Crop Coefficient ◽  
Growth Period ◽  
Water Requirement ◽  
Balance Method ◽  
Growth Stages ◽  
Maize Crop ◽  
Water Balance Method ◽  
Crop Coefficients

The field study was conducted on Lysimeter by employing the soil water balance method to compute the water requirement and Crop coefficient of Maize in the temperate climatic zone of India. Non-weighing type lysimeters (drainage type) of 2 × 1.5 × 2 m was installed to compute the irrigation requirement, actual crop evapotranspiration (ETc) and actual crop coefficient of maize by water balance method. The water requirement of maize was found 410.4 mm using lysimeter data. The mean daily reference evapotranspiration (ETo) of maize ranged from 0.91 mm/day in the starting growth period to 5.29 mm/day at midseason. The peak ETo of Maize was found 6.3mm/day. The computed crop coefficient (Kc) values of Maize for diffrent crop growth stages were 0.53 for intial, 0.93 for development , 1.05 for mid-season, and 0.78 for late season .A Correlation was also established between Penman-Monteith (P-M) and four other reference Evapotranspiration methods.

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%.

COEFICIENTES DE CULTURA PARA O TOMATEIRO IRRIGADO

Irriga ◽  
2011 ◽  
Vol 16 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Marcio José De Santana ◽  
Uander Da Costa Pereira ◽  
José Daniel Cambraia Beirigo ◽  
Stefany Silva De Souza ◽  
Talita Mendes Campos ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Soil Water Balance ◽  
Initial Development ◽  
Class A ◽  
Soil Water Tension ◽  
Crop Coefficients ◽  
Class A Pan

1 RESUMO Um dos métodos de manejo da irrigação mais utilizado é o tanque classe A, necessitando dos valores dos coeficientes de cultura para cálculo da evapotranspiração. O objetivo deste trabalho foi determinar os coeficientes de cultura (Kc) do tomateiro irrigado para a região de Uberaba, MG. Os dados do balanço de água no solo foram obtidos em uma área experimental com a cultura em tratamentos envolvendo níveis de reposição de água no solo (40%, 70%, 100%, 130%, 160% e 190% da lâmina necessária para elevar a umidade do solo para a condição equivalente à capacidade de campo). Os dados de tensão de água no solo foram coletados nas parcelas de 100% de reposição. A evapotranspiração de referência foi obtida pelo método do tanque classe A e a evapotranspiração da cultura por meio do balanço da água no solo. Concluiu-se que os valores de Kc para as fases inicial, desenvolvimento, intermediário, final e colheita foram, respectivamente, de 0,37; 0,72; 1,03; 1,10 e 0,75. UNITERMOS: Lycopersicon esculentum L., coeficiente de cultura, déficit hídrico.  SANTANA, M.J.; PEREIRA, U.C.; BEIRIGO, J.D.C.; SOUZA, S.S.; CAMPOS, T.M.;VIEIRA, T.A. CROP COEFFICIENT FOR IRRIGATED TOMATO  2 ABSTRACT One of the most utilized irrigation management methods is the class A Pan, which requires crop coefficients to estimate crop evapotranspiration. The objective of this work was to determine crop coefficients  (Kc) of irrigated tomato in the region of Uberaba, MG. Soil water balance data were obtained in an experimental area with the culture under six levels of soil water replacement (40%, 70%, 100%, 130%, 160% and 190% of the depth necessary to raise the soil moisture to the field capacity condition). The soil water tension data were collected in plots of 100% replacement. The reference evapotranspiration was obtained by the class A Pan method and culture evapotranspiration was obtained utilizing soil water balance. Kc values for the initial, development, intermediate, final, and harvest phases were respectively of  0.37; 0.72; 1.03; 1.10 and 0.75. KEY- WORDS: LycopersiconesculentumL., crop coefficient, water deficit.

scholarly journals Thornthwaite and mather soil water balance model adapted for estimation of real evapotranspiration of the pasture

2021 ◽  
Vol 29 ◽  
pp. 146-156
Author(s):  
Fabiana da Costa Barros ◽  
Suelen da Costa Faria Martins ◽  
Gustavo Bastos Lyra ◽  
Leonardo Duarte Batista da Silva ◽  
João Paulo Francisco ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Crop Coefficient ◽  
Bowen Ratio ◽  
Soil Water Balance ◽  
Balance Model ◽  
Coefficient Of Determination ◽  
And Performance ◽  
Pasture Area ◽  
Ratio Energy

Determining the real water requirement for pastures is essential for the rational use of irrigation. The aim of this work was to assess the crop coefficient and performance of the Thornthwaite and Mather soil water balance (ThM) adapted to estimate the daily actual evapotranspiration (ETa) of a pasture in relation to the Bowen ratio - energy balance method (BREB). The experiment was carried out from July 2018 to June 2019 in Cachoeiras de Macacu, Rio de Janeiro State (RJ) (22º 27’S; 42º 45’W and 30 m altitude). Micrometeorological and meteorological measurements were conducted in a micrometeorological tower installed in the pasture and also in an automatic weather station, located 1 km from the pasture area. The ThM model was evaluated using linear regression between ETa determinate from BREB and the estimates from ThM using its coefficient of determination (R²) and the modified Willmott agreement index (dm). The ThM model underestimated (between 11 and 16%) the ETa for all seasons, except for spring, which overestimated by 1%. The highest precision and accuracy of the estimates were observed in autumn (R² = 0.84 and dm = 0.68) and spring (R² = 0.83 and dm = 0.82). In summer (R² = 0.56 and dm = 0.73) and winter (R² = 0.43 and dm = 0.66), the lower performance was caused by the inability of the model to represent water extraction from the soil in dry periods.

­Actual Evapotranspiration for Sugarcane Based on Bowen Ratio-Energy Balance and Soil Water Balance Models with Optimized Crop Coefficients.

2021 ◽  
Author(s):  
Suelen da Costa Faria Martins ◽  
Marcos Alex dos Santos ◽  
Gustavo Bastos Lyra ◽  
José Leonaldo Souza ◽  
Guilherme Bastos Lyra ◽  
...  
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Soil Water ◽  
Bowen Ratio ◽  
Balance Method ◽  
Northeastern Brazil ◽  
Soil Water Balance ◽  
Actual Evapotranspiration ◽  
Crop Coefficients ◽  
Ratio Energy

Abstract Evapotranspiration is an important parameter to evaluate soil water deficit and water use efficiency, especially at places with irregularly distributed precipitation.The aim of this study was to assess the daily actual evapotranspiration (ETa) estimated by the Thornthwaite and Mather soil water balance method adapted for crops (ThM) and by the dual Kc approach with the crop coefficients optimized from inversing modeling and by the adjustment procedure suggested in FAO-56. The models comparison and optimization were performed with actual evapotranspiration determined by the Bowen ratio – energy balance method (ETβ) for sugarcane at full canopy closure grown in Alagoas State, Northeastern Brazil. The objective function of the inverse problem was defined in terms of ETβ and ETa estimated by the ThM and dual Kc method by optimizing single crop coefficient (Kc) and the basal coefficient Kcb, respectively. Both optimized Kcand Kcbwere lower than the adjusted KcFAO56, with optimized Kconly 3% less than the Kc obtained experimentally. ETa estimated by ThM and dual Kc models with optimized crop coefficients (Kc = 1.05 or Kcb = 1.00) had similar high precision (r² >0.79) and accuracy (dm>0.93 and RMSE < 0.30 mm d-1), whereas using the coefficients derived from FAO 56 overestimated ETa in both models.

scholarly journals Validation of the ISAREG model for the irrigation management of the melon crop in the state of Ceará

2021 ◽  
Vol 9 (10) ◽  
pp. 119-130
Author(s):  
Kleiton Rocha Saraiva ◽  
Francisco Marcus Lima Bezerra ◽  
Francisco de Souza ◽  
Luis de França Camboim Neto ◽  
Clayton Moura de Carvalho ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Irrigation Management ◽  
Water Storage ◽  
Crop Coefficient ◽  
The State ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Effective Depth ◽  
Soil Climate

The research aimed to validate the ISAREG model, introducing it to water management studies in irrigation in the State of Ceará, comparing results of experimental research, with results of simulations, carried out with the use of software, analyzing the following variables: crop evapotranspiration, variation of soil water storage and water flow in the soil. A bibliographic survey was carried out to obtain soil, climate and crop information required by the model to perform the soil water balance. Aiming at the validation of ISAREG, the model was fed with the following data: reference evapotranspiration, precipitation, phenological phases of the crop, effective depth of the root system, water availability factor in the soil, crop coefficient and soil information. Subsequently, the irrigation management option "dates and irrigation depths" was selected, and ISAREG performed the simulation of the soil water balance. The ISAREG demonstrated a detailed soil water balance, being validated in this study, because when its results were compared to the experimental ones, there was similarity in the trends of the variables analyzed, despite the reduced correlation verified regarding the variation of water storage in the soil.

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