Entity

Time filter

Source Type


Chaterlan Y.,Institute Investigaciones Of Riego Y Drenaje | Hernandez G.,Institute Investigaciones Of Riego Y Drenaje | Lopez T.,Institute Investigaciones Of Riego Y Drenaje | Martinez R.,Institute Investigaciones Of Riego Y Drenaje | And 3 more authors.
Acta Horticulturae | Year: 2012

The papaya (Carica papaya L.) is a main irrigated fruit crop in Cuba and in the tropical and subtropical regions. For environmental and irrigation management purposes, it is important to accurately estimate its crop evapotranspiration and irrigation requirements. The objective of the present study is to determine the crop coefficients (Kc) and the depletion fraction for no stress (p) of the papaya, variety Maradol, as cultivated in southern Havana. Experiments took place during the period March -November, 1997 in an experimental area where soils are compacted red iron soils. The ISAREG irrigation simulation model was applied to those observed data. The calibration of the model consisted in searching the crop coefficients and the depletion fraction for no stress that minimize the differences between observed and simulated available soil water. Several statistical indicators were used to assess the goodness of fit. Results show a good adjustment between observations and model predictions, with the regression coefficient forced to the origin close to 1 (b = 1.01) and a high R2 = 0.86. The root mean square error (RMSE) and the average absolute error (AAE) are small, respectively RMSE = 6.5 mm and AAE = 4.9 mm. After calibration, the model was used to assess the current irrigation scheduling; results show that irrigation dates were anticipated relative to the required and irrigation depths were excessive, thus significant percolation occurred. The ISAREG model will be further used to generate and evaluate alternative irrigation schedules aimed at improved water productivity. Source


Chaterlan Y.,Institute Investigaciones Of Riego Y Drenaje | Leon M.,Institute Investigaciones Of Riego Y Drenaje | Duarte C.,Institute Investigaciones Of Riego Y Drenaje | Lopez T.,Institute Investigaciones Of Riego Y Drenaje | And 2 more authors.
Acta Horticulturae | Year: 2011

A proper soil water balance model provides support to improved irrigation management. With this objective, the water balance simulation model ISAREG was calibrated and validated for micro-sprinkler irrigated sweet pepper, garlic, onion, cabbage and carrots, using field observations performed in the Irrigation Station of Alquízar, south of La Havana. Model calibration and validation were performed using two independent data sets for each crop. The calibration refers to the crop coefficients (K c) and the soil water depletion fraction for no stress (p), and to the soil hydraulic properties of a Red Ferralitic compacted soil. The calibration procedure consisted of adjusting first the soil properties and then, through an iterative procedure, to determine the K c and p values that minimize the differences between observed and simulated soil water content along the crop season. The validation was performed using the calibrated K c and p with a different climate and crop data sets. The following indicators of goodness of fitting were used to assess model calibration and validation: regression coefficient forced to the origin (b), determination coefficient (R 2), root mean square error (RMSE) and average absolute error (AAE). Results show a good agreement between field observations and model predictions for all the five crops, with b close to 1.0, R 2 ranging 0.84-0.95 for the calibration and 0.78-0.90 for the validation. The RMSE ranged between 0.97 and 2.08 mm for the calibration and between 1.07 and 2.82 mm for the validation. The K c and p values are in the range suggested in FAO 56 manual and other literature papers. Results allow further using the model to develop alternative irrigation schedules aimed at improved water use and productivity in Cuba. Source

Discover hidden collaborations