ESIEKPE ONOME

Efficient water management is important for sustainable agricultural production, particularly in regions experiencing climatic variability and limited water resources. This study focuses on determining evapotranspiration rates for maize (Zea mays) and rice (Oryza sativa) crops using selected evapotranspiration models under the climatic conditions of Ovia North East LGA, Edo State. Two ET models- the Blaney Morin Nigeria (BMN) and Hagreaves- Samani methods were semployed to estimate reference evapotranspiration (ETo) based on meteorological data obtained from the Nigerian Institute for Oil Palm Research (NIFOR) station. Crop evapotranspiration (ETc) was subsequently derived by applying crop coefficients (Kc) corresponding to the different growth stages. The study compared the performance of both models to evaluate their suitability for local conditions. Results indicated that the BMN model, which uses relative humidity alongside temperature and daylength, produced ET estimates more consistent with humid tropical conditions than the temperature based Hagreaves- Samani model. It was also found that using BMN instead of Hagreaves- Samani model reduces estimated irrigation demand by 85% for both maize and rice, corresponding to water savings of about 8,587 m³/ha and 10,230 m³/ha and approximate energy savings of 390kWh/ha for maize and 456kWh/ha for rice. The findings highlight the importance of using locally calibrated ET models for accurate irrigation scheduling and water resource management. This study provides valuable insights for improving water use efficiency, enhancing crop yield, and promoting climate smart agricultural practices in southern Nigeria.