Author(s): TAVARES, S. R. de L.; RODRIGUES, N. F.; CORRÊA, G. M.; HÜTHER, C. M.

Summary: Currently, there are various methods for determining the Class A pan coefficient (Kp) in estimating reference evapotranspiration (ETo), which is of utmost importance for water management in agriculture. This study aimed to estimate ETo inside and outside agricultural greenhouses using a low-cost constructed Class A pan (TCA-c) method. To estimate ETo, it is necessary to establish the Kp, as ETo is the product of ECA multiplied by Kp. This study employed the calibration method, comparing ETo determined by Penman-Monteith (EToPM) with Class A pan evaporation (ECA) to determine Kp. EToPM served as the standard for correlations with reference evapotranspiration using the TCA-c method inside and outside an agricultural greenhouse, avoiding the installation of a "Class A" pan inside the greenhouse. The experiment was conducted at UFF's Gragoatá campus in Niterói - RJ. Four TCA-c pans were installed (three inside and one outside an agricultural greenhouse) and managed for one year. Principal Component Analyses (PCA) revealed significant differences in ETo throughout the seasons. Adjusted Kps were established for all pans. It was observed that ETo inside the greenhouse was lower than that estimated outside. It is recommended to install the TCA-c pan inside the greenhouse for ETo estimation, utilizing different Kps throughout the seasons.

Publication year: 2024

Types of publication: Book sections

Unit: Embrapa Soils

Keywords: Class A Pan, Evapotranspiration, Evapotranspiração, Pan coefficient