The irrigation world has become an alphabet soup –LESA, MESA, LEPA, SDI – but a new Texas AgriLife Extension Service publication can help producers “spell out” feasibility, efficiency and water savings by selecting the right system for their operation.

The new “Economics of Irrigation Systems” publication is a collaborative work by AgriLife Extension, West Texas A&M University and Texas AgriLife Research economic and irrigation specialists and agricultural engineers. The research was supported in part by the Ogallala Aquifer Program.

“Irrigation can improve crop production, reduce yield variability and increase profits,” said Dr. Steve Amosson, AgriLife Extension economist. “But choosing and buying the appropriate irrigation system is both expensive and complex.”

The producer must determine water availability, financing, crop mix, energy prices, energy sources, commodity prices, labor availability and costs, tax rate, soil type, savings in field operations, application efficiency, operating pressure of the design and pumping lift—all before selecting an irrigation system, Amosson said.

“The less efficient the irrigation system, the more effect that fuel price, pumping lift and wage rate have on the cost of producing an irrigated crop,” he said. “Therefore, when there is inflation or volatility of these cost factors, it is more feasible to adopt more efficient irrigation systems and technology.”

To assist producers in these decisions, the researchers identified the costs and benefits of five types of irrigation systems commonly used in Texas: furrow irrigation; mid-elevation spray application or MESA center pivot; low-elevation spray application or LESA center pivot; low-energy precision application or LEPA center pivot; and subsurface drip irrigation or SDI.

Some of the findings include:

  • Furrow irrigation systems require less capital investment, but have lower water-application efficiency and are more labor intensive.
  • Center-pivot systems offer more than enough benefits in application efficiency and reduction in field operations to offset the difference in cost of furrow irrigation.
  • Half-mile center pivot systems offer substantial savings compared to quarter-mile length systems where it is feasible to use them.
  • The low-energy precision application system generates the highest benefits at low, intermediate and high water-requirement scenarios.
  • Advanced irrigation technologies are best suited to high-water-use crops and producers with these systems will not only lower pumping costs, but also see potential savings from the need for fewer field operations.
  • Subsurface drip irrigation is not economically feasible compared to LEPA for typical crops grown because of the high investment and small gain in application efficiency. It is best adopted where pivots cannot physically be installed. However, producers should closely evaluate using subsurface drip for high-value crops such as fruits, vegetables and cotton. Research suggests this system may improve yields enough to offset costs through improved application efficiency and the timing of frequent applications.

“We identify in the publication the economic feasibility of replacing inefficient natural gas engines with more efficient models,” Amosson said. “In another section, we analyze the decision of when to switch from natural gas-powered irrigation to electric-powered irrigation.”

Amosson said the publication will allow producers to plug in the factors on their particular operation and, after looking at all the inputs, determine whether they need to be making changes or updates to their irrigation system.

The 14-page brochure can be found online at http://agrilifecdn.tamu.edu/amarillo/files/2011/10/Irrigation-Bulletin-F... or http://agecoext.tamu.edu/resources/library/publications.html. A printed copy can be purchased for $5 per copy through the AgriLife Extension Bookstore at http://agrilifebookstore.org.

For more information, contact Amosson at 806-677-5600 or s-amosson@tamu.edu .