Author
PICCINNI, G - TAMU | |
LESKOVAR, D - TAMU | |
KOLENDA, K - TAMU | |
MAREK, T - TAMU | |
DUSEK, D - TAMU | |
Howell, Terry |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 9/22/2005 Publication Date: 9/24/2005 Citation: Piccinni, G., Leskovar, D.I., Kolenda, K.A., Marek, T.H., Dusek, D.A., Howell, T.A. 2005. Development of phenological-stage-specific crop coefficients (Kc) to manage deficit irrigation in agricultural production systems. InterDrought-II, The 2nd International Conference on Integrated Approaches to Sustain and Improve Plant Production Under Drought Stress, September 24-28, 2005, Rome, Italy. Interpretive Summary: Technical Abstract: In-ground weighing lysimeters are used to measure real time crop water use during the growing season. By relating the water use of a specific crop to a well-watered reference crop such as grass or alfalfa, crop coefficients (Kc) can be developed to assist in predicting accurate crop needs using meteorological data available from weather stations. Reference evapotranspiration (ETo) can be obtained from several weather networks, however, without crop coefficients for specific crops, this information is only useful for grass or alfalfa. Five weighing lysimeters, consisting of undisturbed 1.5 x 2.0 m by 2.2 m depth cores of soil, comprise the Texas A&M Research and Extension Center - Uvalde lysimeter facility. Four lysimeters, weighing around 15,000 kg, have been placed each in the middle of a 1 hectare field beneath a linear LEPA (low energy precision application) irrigation system and used in field production. A fifth lysimeter irrigated by subsurface drip irrigation system located in a 0.5 hectare grassed area nearby was established to measure ETo. Maize, sorghum, spinach and onion were grown over the last three years in the crop lysimeters. Daily water use was measured on 5-min intervals. Results show the possibility of saving approximately 61 to 74 million m3 of water per year in the irrigated farms of the South Texas region if proper irrigation management techniques are implemented in conjunction with the newly developed crop coefficients. Crop water |