Comparing Water Use Efficiency in South Texas Furrow and Drip Irrigated Cabbage

Vegetable production in the Lower Rio Grande Valley of South Texas is at continual risk of failure due to periodic and extreme drought conditions.  Irrigation sources stem from the Rio Grande River, and when water resources are limiting growers need to change to more water conserving methods to raise horticultural crops.  The purpose of this project was to evaluate drip irrigation as a water conservation strategy to conventional furrow irrigation for cabbage production.  Crop water requirements were estimated using a weather station, Penman-Monteith evapotranspiration (ET) equation, and FAO crop coefficients.  Plots were replicated using a completely randomized design with sub-sampling.  Matrix-based soil moisture sensors were used to monitor soil water content for irrigation scheduling, and determined by replacing ET water loss within the drip irrigated plots versus irrigating to soil saturation point in furrow irrigated plots.  Irrigation was applied when the soil water sensor reached a soil water level of 30 centibars for drip and 50 centibars for furrow.  The furrow system was irrigated to advance water to the lower end without producing runoff by blocking the furrows.  Harvested cabbage was measured for size and weight to determine marketable yield and produce quality which was determined by the characteristics of the variety.  The yield and produce quality was used to determine water use efficiency for the two irrigation methods.