|HOWELL, TERRY - Retired ARS Employee|
|Baumhardt, Roland - Louis|
|PORTER, DANA - Texas Agrilife Extension|
|MAREK, THOMAS - Texas Agrilife Research|
|NANGIA, VINAY - National Center For Agricultural Research And Extension (NCARTT)|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2016
Publication Date: 3/15/2016
Citation: Gowda, P.H., Howell, T.A., Baumhardt, R.L., Porter, D.O., Marek, T.H., Nangia, V. 2016. A user-friendly interactive tool for estimating reference ET using ASCE Standardized Penman-Monteith Equation. Applied Engineering in Agriculture. 32(3):383-390. 10.13031/aea.32.11673.
Interpretive Summary: Crop water use can be estimated using daily reference evapotranspiration (ET) and an appropriate crop coefficient.Reference ET is useful for calculating irrigation demand. We present a new user-friendly computer tool for calculating hourly and daily reference ET and weather data is used. Both grass and alfalfa reference ET values are calculated. The software was designed for producers and crop consultants to use in irrigation scheduling, it can also be used for training and research purposes.
Technical Abstract: Accurate daily reference evapotranspiration (ETref) values are needed to estimate crop water demand for irrigation management and hydrologic modeling purposes. The Bushland Reference ET Calculator (BET) was developed by the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas for calculating hourly and daily grass and alfalfa ETref. The user-friendly interface for the calculator was developed using the Java Programming Language. The calculator uses the American Society of Civil Engineers (ASCE) Standardized Penman-Monteith ETref equation for calculating both grass and alfalfa reference ET values at hourly and daily time steps, from a single set or time series of weather data. Daily ETref can be calculated either by calculating the hourly ETref values for a given day and summing them up or by calculating a daily value using daily statistics of the climatic data (means, maxima and minima). Graphing capabilities include line graph and scatter plot for quality assurance and quality control purposes. Descriptive statistics can be calculated for selected or all of the variables. Although the "Bushland Reference ET Calculator" was designed and developed for use mainly by progressive producers and crop consultants to manage irrigation scheduling, it can also be used in educational training, research, and other practical applications. This paper demonstrates the use of the Bushland Reference ET Calculator that is available from the USDA-ARS Conservation and Production Research Laboratory web site to interested users at no cost.