Field day audience hears prospects for rice, soybean crops

Aug. 22, 2011
Contact Information:

Roger Eason, Director, Pine Tree Research Station, Colt
870-633-5767 /

Dave Edmark, Division of Agriculture Communication Services
479-575-5647 /

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nathan slaton and soybean plants

Nathan Slaton, professor of crop, soil and environmental sciences, shows soybean plants that are suffering from boron deficiency during the Pine Tree Research Station field day.
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COLT, Ark. -- The field day became an indoors day at the University of Arkansas Division of Agriculture's Pine Tree Research Station on Thursday, Aug. 17. Dark skies and a strong thunderstorm rolling through St. Francis County greeted the early morning crowd.

"It's hard to apologize for rain in August," said station director Roger Eason, but as the rain continued past the starting time he cancelled the outdoor field tours and all the presenters delivered their reports from a podium instead a farm plot.

The Division's new N-ST*R program (Nitrogen Soil Test System for Rice) will enable researchers to process at least 5,000 soil samples in its first year, said Trent Roberts, research assistant professor of crop, soil and environmental sciences. The program is a nitrogen management tool for direct-seeded, delayed-flood rice. He encouraged rice producers using silt loam soils to get samples in early as the service will be on a first-come, first-served basis. There will be a $5 per sample charge.

"There is a lot of potential reward for using this technology," Roberts said. "It really comes in terms of potential to reduce nitrogen fertilizer rates or increase your yield if you need to put out more nitrogen. We're going to see reduced disease."

The Division of Agriculture is collaborating with Louisiana State University and Mississippi State University in research to examine the use of GreenSeeker sensor technology for mid-season nitrogen application. Roberts said the soil fertility program's goal in the next five years is to have a system in place that answers nitrogen fertilizer needs either through soil testing with N-ST*R or sensor technology.

The weather patterns of the past spring and summer have affected rice production around the state, said Karen Moldenhauer, professor of rice breeding and genetics at the Rice Research and Extension Center. She noted that spring planting was late and then fields were hit by significant rainfall. Sixty percent of the rice crop was planted by mid-May, a level that had been reached by April in each of the previous five years.

"It may turn out to be beneficial," Moldenhauer said. But the high temperatures of summer could still take a toll. "We need cool nights," she added, for optimum grain fill for better milling.

Rice has been at risk from stink bugs but the word got out to producers to take precautions. Gus Lorenz, an Extension entomologist, said a typical sweep of a field would turn up 200 to 300 stink bugs.

"We were concerned about that issue but our growers went out and made their applications," Lorenz said. "They got 90 percent control in those situations." As heads formed on the rice, stink bugs dispersed over the acreage at a level easier to control. After rice bloomed, the stink bugs made a transition.

"They like seed," Lorenz said. "They don't like rice in bloom. They're seed feeders. So when the rice transition started turning over, they started moving into the older rice that was two, three or four weeks into heading. When you're in the second, third or fourth week of heading, that's when you're protected from pests."

Soybean growers need to beware of allowing their crop to become deficient in boron, said Nathan Slaton, professor of crop, soil and environmental sciences. Once a plant becomes deficient, it may be too late to cure the problem. The key is to spray the plants early. "If you're sitting on silt loam soil west of Crowley's Ridge and north of Interstate 40, a little boron goes a long way. Preventive fertilization means a lot," Slaton said.

Slaton also warned against cutting back on fertilizing with potassium and phosphorous as many corn, rice and wheat farmers have done since price increases a few years ago. With these two fertilizers, he said, "you don't always get deficiency symptoms and many of our soils have a little bit of reserve there. We can get by with a couple of years of cutting back, but you can't get by forever."

He also noted that long-term mismanagement of potassium fertilizer can have significant effects. After planting early a high-yield rice variety, researchers have seen up to a 90-bushel yield difference between unfertilized control plants and those with just above average fertilization rates.

Pigweed continues to plague the state's soybean farmers. Bob Scott, an extension weed scientist, said pigweed is a more common sight this year at a much higher level of infestation. Now that glysophate is no longer an effective tool to fight pigweed, farmers need alternatives.

"We did see a big increase in the use of residuals this year," Scott said. "I think residuals are a big part of the answer to this pigweed problem." He recommended applying residual herbicides early and to look out for two-inch pigweeds before they grow.

"We didn't have to do that with Roundup. We can kill these (small ones). When they get knee high, pigweed in Arkansas is uncontrollable."