Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/22/2003
Publication Date: 11/3/2003
Citation: PICCINNI, G., LAFFERE, M.K., KOLENDA, K.A., MAREK, T.H., DUSEK, D.A., HOWELL, T.A. 2003. DETERMINATION OF CROP COEFFICIENTS AND WATER USE OF CORN. ANNUAL MEETING ABSTRACTS 2003. ASA-CSSA-SSSA, DENVER, CO. 2003 CDROM. Interpretive Summary:
Technical Abstract: The depletion of the Edwards aquifer and the competition for water with urban areas has limited water available for irrigation. This limitation restricts growers in the Edward aquifer region to pump limited amounts of water per year based on historical use. Lysimeters are used to measure real time water use during the growing season. By relating the water use of a specific crop to a well-watered reference crop such as alfalfa or grass, crop coefficients (Kc) can be developed to assist in predicting accurate crop needs using available meteorological data. Reference evapotranspiration can be obtained from several weather networks, however without crop coefficients for specific crops this information is only useful for grass. Three weighing lysimeters, consisting of undisturbed 1.5 m x 2.0 m area by 2.2 m depth cores of soil, comprise the Texas A&M Research and Extension Center - Uvalde lysimeter facility. Two lysimeters, weighing around 15,000 kg, have been placed beneath a linear LEPA irrigation system and used in field production. A third lysimeter measures reference ET values (ETo) and is located in a grassed area located near the field lysimeters irrigated by subsurface drip irrigation system. A corn crop was grown in the two crop lysimeters and daily water use was measured on a 5-minute interval. Crop water requirements and Kc determination will be discussed.