Arkansas Pit-less Tailwater Pump Reaches Market After Decade of Testing

A furrow-irrigated rice system developed over more than a decade at the University of Arkansas cut irrigation water use by 27% and added 15.3 bushels per acre in three-year trials — and farmers can now buy it. Irrigation-Mart, Inc. is manufacturing and selling the patented Pit-less Tailwater Pump under a license through the University of Arkansas Division of Agriculture's Technology Commercialization Office.

"This is an important step because farmers can now purchase this technology and put it to work on their farms," said Christopher Henry, the technology's inventor and a professor and water management engineer with the Arkansas Agricultural Experiment Station and the Cooperative Extension Service, UADA's research and outreach arms.

What does the pump change for row rice?

The economics center on levee costs. Converting flooded fields with levees back to furrow irrigation in a rice-soybean rotation runs $95 per acre or more in tillage and labor. On heavier clay soils the bill climbs: Brad Watkins, a professor in UADA's department of agricultural economics and agribusiness, said some producers pull levees as many as six times just to form them.

Harvest savings compound the difference. "The biggest difference in costs would be harvesting costs associated with moving a combine across a furrow-irrigated field faster than a levee field," Watkins said.

Henry adds agronomic flexibility that flooded rotations lack: cover crops, no-till or reduced tillage, and biochar amendments fit more easily into row rice than into fields that regularly switch between soybeans and flooded rice.

The yield gap was the historical barrier. Previous UADA research found conventional furrow-irrigated rice yielded 16.7 fewer bushels per acre than rice grown under a levee system. With the Pit-less Tailwater Pump, yields have not differed from nearby flooded fields — though these are researcher-run comparisons, not independent on-farm audits.

What do the trial numbers show?

In a three-year rice comparison, the system averaged 190.4 bushels per acre using 16.1 acre-inches of irrigation water. A conventional three-day irrigation treatment in furrow-irrigated rice produced 175.1 bushels per acre on 22.1 acre-inches. That works out to a 24% improvement in total water-use efficiency.

"The system really solves many of the downsides of furrow-irrigated rice," Henry said. "It gives farmers a practical tool that allows them to use less water, keep water on the field, plant sooner, have more consistent grain moisture from top to bottom of the field, harvest faster, reduce machinery cost, reduce energy cost for irrigation, and have improved yields in years with less summer rainfall."

One early adopter backs the claim. Stephen Hoskyn, an Arkansas farmer, used a pre-production unit to win UADA's Most Crop per Drop irrigation contest. "I would not grow row rice without this system," he said. A single contest result is thin evidence; the three-year averages carry more weight.

How does installation work?

Henry says the design targets affordability and farmer installation. The system consists of a prefabricated sump, lid, lightweight pump and standpipe assembly. Its low power requirement allows installation far from utility power using smaller, direct-bury wires, and the whole unit is semi-portable for rotating between fields.

UADA has not published a retail price for the Irrigation-Mart units.

Who pays, and by when?

Arkansas farmers may qualify for cost-share through USDA's Natural Resources Conservation Service Environmental Quality Incentives Program, with an EQIP application deadline of Nov. 20.

Cooperative Extension Service offices in all 75 Arkansas counties can advise on the technology. Joe Schafer, an irrigation program associate with UADA, or local USDA NRCS offices can arrange site visits; Schafer or Henry will develop a plan and help with the EQIP application, with support from the Arkansas NRCS.

Research, development and commercialization drew funding from the U.S. Department of Energy, the Arkansas Rice Research and Promotion Board, the NRCS in Arkansas, and the Arkansas Soybean Promotion Board.

Whether the trial yields hold across commercial fields and soil types will become clear as the first buyers run the pump through a full rotation.