Determination of Rice Crop Coefficient Using Modified Microlysimeter

Philippine Journal of Agricultural and Biosystems Engineering; Roger Luyun, Jr.; John Ruzzel Galoso; Rosa Delos Reyes; Jeffrey Gonzales

doi:10.48196/016.01.2020.05

Philippine Journal of Agricultural and Biosystems Engineering
Roger Luyun, Jr. University of the Philippines Los Baños
John Ruzzel Galoso University of the Philippines Los Baños
Rosa Delos Reyes University of the Philippines Los Baños
Jeffrey Gonzales University of the Philippines Los Baños

DOI: https://doi.org/10.48196/016.01.2020.05

Keywords: crop coefficients, microlysimeter, crop water requirement, rice, CROPWAT, FAO PenmanMonteith

Abstract

Accurate estimates of crop water requirements are needed in the proper design and management of irrigation systems, and to improve irrigation efficiency. These require knowledge of location-specific crop coefficients (Kc) together with climate-specific reference crop evapotranspiration (ETO). This study aimed to determine Kc values for PSB Rc18 rice variety at each growth stage. A modified microlysimeter setup was used to estimate crop evapotranspiration (ETC) while local climatic data was used in the FAOPenman-Monteith equation to determine ETO. The computed average Kc values during the initial, vegetative, reproductive, and late stages for rice are 1.02, 1.15, 1.14, and 0.78, respectively. These estimated Kc values are very close to locally established and FAO recommended values.

Citation:

LUYUN, R., JR., GALOSO, J. R., DELOS REYES, R., & GONZALES, J. (2020). Determination of Rice Crop Coefficient Using Modified Microlysimeter. Philippine Journal of Agricultural and Biosystems Engineering, 16(1), 55–62. https://doi.org/10.48196/016.01.2020.05