Crop yield response to water - Cra

Table 2Additional information and data needed for parameterization and validation of AquaCrop.The required data include those not mentioned here but listed in Column 2 of Table 1.1. Minimal additional beyond Column 2 of Table 1 2. Additional for reliable parameterizationPeriodic measurements of leaf area index(LAI) or canopy cover over the seasonCropPeriodic measurements of above-groundbiomass over the seasonDate when foliage canopy begins to turnvisibly yellowMeasured rooting depthSigns of water stress and datesData as in Column 1 but obtainedat several locations and climates ondifferent soil typesClimate and ETDaily maximum and minimum temperatureand humidityDaily solar radiation and wind runET by soil water balance (optional)Data as in Column 1 but obtainedat several locations and climates fordifferent soil typesMeasured daily ETSoil and fertilityMust have one treatment with optimal soilfertilityField capacity and permanent wilting pointof soil horizonsInfiltration rate or saturated hydraulicconductivity of the soilData as in Column 1 but obtainedat several locations and climates fordifferent soil typesIrrigation and water in soilMust include a well-watered (full irrigation)treatment and water-stress treatmentsAmount of water applied at each of theirrigationsMeasured or good estimate of soil-watercontent for different soil depths at plantingPeriodic measurements of soil-watercontents at various depths of the root zone(optional alternative to soil-water balance)Data as in Column 1 but obtainedat several locations and climates fordifferent soil typesMust include treatments with waterstress at different times and differentseveritiesRule 3: Differentiate the input information and measured or observed data according to theirreliability and exactness, and make rational adjustment to the vague or rough estimates ofinput first to see if the simulated results better match the measured results, before changingthe model parameters. In later Sections, many of the uncertainties of the input informationor data, and the measurements taken on crops, are mentioned and discussed to decide whichinputs can be altered based on a rational evaluation of its likely range of uncertainty.Rule 4: When simulated results and measured data do not agree, the problem could alsobe in the measured data. If simulated results coincide with measured data obtained inseveral different studies, but not with that of another study, the data in the other studyare more suspect and additional data sets should be sought to complete the validation orparameterization.AquaCrop parameterization, calibration, and validation Guide 73