The "pyfao56" package for Python: Codifying FAO-56 Evapotranspiration in a Modern Programming Language

The “pyfao56” software package is a Python-based implementation of 1) the American Society of Civil Engineers (ASCE) Standardized Reference Evapotranspiration Equation and 2) the Food and Agricultural Organization of the United Nations (FAO) Irrigation and Drainage Paper No. 56 (FAO-56) dual crop coefficient methodology. The software was initially developed to support crop water use estimation and irrigation scheduling for field research at the Maricopa Agricultural Center in Arizona. More recently, the software was updated to include a more comprehensive soil water balance approach, which was previously developed for evapotranspiration (ET) field research at the Limited Irrigation Research Farm in Colorado. The goals of pyfao56 development were to codify the standardized ET algorithms in a modern programming language, release the software to open-source software repositories such as the Python Package Index (PyPI) and Github, and make the standardized ET algorithms available to a new generation of scientists with aspiration for modern software functionality and accessibility. Efforts to generalize and modularize the software design have increased its applicability and relevance for scientific studies on crop evapotranspiration and irrigation management worldwide.