SAVING WATER WITH PIVOT IRRIGATED RICE
Brian Protheroe is a fourth-generation Australian farmer who has been growing flood irrigated rice since 1995. But because of water shortages caused by recent dry years and the bullish price of rice, Protheroe decided to grow rice with efficient Zimmatic center pivot irrigation.
Protheroe had lots of experience raising traditional flood irrigated rice but little knowledge of growing rice under pivot irrigation. He did his research on pivot irrigated rice, including a trip to the United States to visit the Michael McCarty rice farm near Osceola, Arkansas.
McCarty’s successful experiences raising rice under pivot irrigation were documented in a study showing substantial water, labor and energy savings and yields on par with flood irrigated rice.
He planted two varieties of rice: Quest, a short-season, short-grain variety, and Amaroo, a long-season, short-grain variety, on 74 acres (30 ha) of land known locally as the Glen Ayre Farm.
“I wanted to grow two different varieties with two different maturities in order to establish which variety was better suited for pivot irrigation.”
Groundwater is the main source for his four Zimmatic center pivot irrigation systems, but Protheroe plans to add more pivots and pump stations to access water from a nearby river.
Protheroe used a large 60-foot (18.3 m) planter to plant the rice, something he had previously not been able to do because of the dikes and berms that are used in flood irrigated rice fields.
The Zimmatic rice pivot on Protheroe’s farm is 991 feet (302 m) long and includes six towers. The new pivot was equipped with a Nelson S3000 Yellow Plated Spinner sprinkler package, which applied fine droplets of water “like a good steady rain,” Protheroe said.
The rice pivot was outfitted with Lindsay’s Z-TRAX tracking system and three-wheel drive tubes for improved traction and flotation. “The Lindsay tracking systems helped enormously,” he said.
Because pivot irrigated rice can be planted on sloped fields of up to 30 degrees and doesn’t require costly field-leveling, dikes and canals, Protheroe was able to plant his rice on ground that had been in wheat the year before.
“Not having to do dikes was key and really convenient, especially for my operation. We have large equipment, and I was able to go right into the field with our large seeder. With dikes and berms, I couldn’t do that,” Protheroe says.
Fertilizer was applied through the Zimmatic pivot, a tractor spreader and an airplane.
Protheroe was extremely pleased with weed control in the pivot irrigated rice.
“One of the many benefits of rice production under a pivot is the ability to apply herbicides using existing equipment such as sprayers,” says Bryce Yates, managing director at Flow Smart, Protheroe’s local Zimmatic dealer. “With flood irrigation, this has to be done by airplane, which is much more expensive.”
Protheroe’s short-season rice variety yielded 195 bushels dry per acre (9.8 MT/ha), with some sections yielding up to 297 bushels dry per acre (15 MT/ha). The long-season rice variety yielded 105 bushels dry per acre (5.3 MT/ha).
“I planted the short-season rice variety because the nights can get cool in our area around the end of December through mid-January, which can damage yield when the rice is heading. As it turned out, yields on the short-season variety were outstanding. I was very pleased with the yield on the short-season rice.”
Protheroe conservatively estimates using 40 percent less water growing pivot irrigated rice compared to flood irrigated rice.
Protheroe plans to continue growing pivot irrigated rice, depending on how dry it is in his area and the market price of rice.
Visit http://www.zimmatic.com/ for more information.