Actual evapotranspiration and crop coefficient of sweet orange during the initial development phase in the Rio Largo region, Alagoas
| Autor: | Ricardo Barros Silva, José Leonaldo de Souza, Ricardo Araújo Ferreira Júnior, Marcos Alex dos Santos, Renan Cantalice de Souza, Wellington Manoel dos Santos |
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| Jazyk: | English<br />Portuguese |
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| Zdroj: | Ciência Rural, Vol 49, Iss 6 |
| Druh dokumentu: | article |
| ISSN: | 1678-4596 0103-8478 |
| DOI: | 10.1590/0103-8478cr20180707 |
| Popis: | 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. |
| Databáze: | Directory of Open Access Journals |
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