Comparing Citrus Irrigation
Three-year alternative irrigation system averages versus traditional flood
By Heriberto “Eddie” Esquivel
Under the direction of Dr. Shad Nelson, assistant professor at Texas A&M University-Kingsville, Eddie Esquivel has been working since March 2005 to establish citrus irrigation demonstration sites throughout the Rio Grande Valley. Nelson and Esquivel work closely with the Texas AgriLife Extension Service and Dr. Juan Enciso, Extension specialist, and Xavier Peries, Extension technician, sharing resources and gathering data on sites established by Enciso.
Data collected for the past three years includes: rainfall at each site, soil moisture levels and yields. Using one crop, such as Rio Red grapefruit, a perennial luxury crop for the Lower Rio Grande Valley (LRGV) can be compared between different growers throughout the LRGV.
Differences in soil type, rainfall events and available water can vary from county to county, site to site. These differences will dictate water usage for commercial citrus growers. Typically irrigation of citrus is done with wide area flooding, adding approximately 0.6 acre-feet of water per irrigation event. Traditional flood events are calculated using this method unless there are metering devices that accurately measured water flow.
“By comparing individual sites using alternative irrigation methods, our goal is to illustrate potential water savings over traditional flood irrigation techniques,” Nelson said. “Irrigation methods used are bordered flood, microjet spray and drip irrigation.”
All sites from each irrigation type were compared to traditional flood’s average gallons per acre during the past three growing seasons of the Rio Red grapefruit. With traditional flood at 0.6 acre-feet per irrigation event, there are six to eight events depending on rainfall. Traditional flood averaged approximately 1,176,206 gallons per acre or 3.61 acre-feet.
Micro-jet irrigation and bordered flood were close in water usage compared to drip irrigation, showing a potential savings of 1.58 acre-feet of water.
“The demonstration project is achieving good working results,” Nelson said. “Until we can accurately measure traditional flood plots, we must use the well-known figure of 0.6 acre-feet per acre for each irrigation event. While water costs and availability are good, farmers will use the most cost-effective means to irrigate their citrus orchards.”
This research is part of the Agricultural Demonstration Initiative funded by the Texas Water Development Board and supported by the Rio Grande Basin Initiative.
