Estimation of evapotranspiration and crop coefficient of asparagus in semi-Arid region of Mexico using NDVI remote sensing data

The objective of this study is to estimate the crop coefficient (Kc) and actual evapotranspiration (ET) of asparagus in semi-Arid environment of Sonora in northwestern Mexico. Kc values were derived from normalized difference vegetation index (NDVI) acquired by Sentinel-2 satellite data through a linear relationship (R2=0.85). The established relationship between Kc and NDVI was then used to calculate ET and validate by eddy covariance (EC) measurements. The results indicate an accurate estimation of ET with an R2 of about 0.85 and a root mean square error (RMSE) of 0.96 mm day-1. The results obtained in this study show great potential for estimating asparagus water requirements. It is expected to serve as a practical tool for improving irrigation water management, which is of critical interest in arid and semi-Arid regions where water is becoming increasingly scarce.