FAYETTEVILLE, Ark. – Standing in a cotton field several counties away from the state’s prime cotton-producing regions, high school students from northwest Arkansas got a close look at new ways cotton farmers are guarding against adverse conditions that can harm their crop. The students observed research scientist Derrick Oosterhuis showing how to manage cotton growing in stressful conditions during a field trip showcasing research at the University of Arkansas System Division of Agriculture.

“All these measurements are to detect deficiencies in nutrients or in water,” Oosterhuis said in front of a demonstration plot several feet away from a main Fayetteville thoroughfare. “The whole idea here is to predict as early as possible when your crop is going to run out of fertilizer and water. You can act accordingly to optimize yield.”

The occasion was the sixth annual environmental and agricultural sustainability field trip Sept. 23 at the Arkansas Agricultural Research and Extension Center about two miles north of the Fayetteville campus sponsored by the university’s Department of Crop, Soil, and Environmental Sciences. More than 200 students from Fayetteville, Mountainburg, Springdale, Springdale Har-Ber, and Rogers high schools and Haas Hall Academy in Fayetteville toured the Division’s farm facilities to hear short sessions hosted by faculty and staff.

Cotton wasn’t the only topic on the tour. The high school students also had opportunities to hear presentations and view demonstrations on soybean seed crossing, wheat breeding, soil profiles, switchgrass production, water quality monitoring, erosion and environmental sustainability, biodiesel plant activity, a Beaver Lake watershed model, the role of crops in biological fuels and fertilizers and soybean production research.

“Our department began this event to introduce environmental and agricultural sustainability issues to area students,” said Holly Yeatman, recruiting coordinator for the Department of Crop, Soil, and Environmental Sciences. “Most people have a limited understanding of the impact of environmental and agricultural practices on one another. In CSES, we are educating students to understand these issues and equipping them to solve problems that may arise in the future.”

Yeatman said the field trip is popular with both students and teachers. Students have told her how much they learned and that they enjoyed the faculty presentations. One student told her it was a “fun, interactive experience” and another said they wanted more time for the event. “Teachers tell me that this is an excellent learning experience for their students, and that they refer to this event throughout the year as they teach related topics.”

Oosterhuis, a distinguished professor in the department, explained to students that high temperatures are a major problem for cotton producers, and not just in the broiling Arkansas summer afternoon sun. Even with slightly cooler temperatures at night, things aren’t much better for the crop.

“High night temperatures might be more important than high day temperatures,” he said. “In the Delta, you have high humidity and clouds and it keeps the heat from escaping into the atmosphere at night. Our plants stay hotter at night than in the drier areas such as California.”

High temperatures at night bring increased respiration, which breaks down sugars with oxygen and releases carbon dioxide by plants. Oosterhuis said the result is the cotton plants “have less sugar available to the flowers the next day, resulting in poor pollination and poor seed growth. The overall effect is you get less seed, less fiber on the seed and lower yield.”

Cotton is sensitive to temperature stress throughout its growth cycle, particularly during the flowering stage. Oosterhuis and his research team have been exploring the implications by creating varied temperature settings for cotton plants both in the field and in controlled environmental chambers, peaking at 100 degrees Fahrenheit. “Then we measure all kinds of physiological and biochemical processes to see how the plant is reacting,” he told the students.

Lately, temperatures in Arkansas have been cooler than recent summers and cotton isn’t growing as quickly. Cotton bolls would normally be opening at this time of year but many are still green and closed. “We’ve had enough sunlight for photosynthesis (the conversion of light energy to chemical energy in a plant) but not enough heat for the bolls to fully mature,” Oosterhuis said.

The Division of Agriculture’s cotton researchers are also examining effects of drought stress and water shortages. They are measuring metabolic changes in different varieties to compare their responses to the stress. Knowing which varieties show more tolerance, and what meatabolic process is causing the tolerance, helps breeders improve existing varieties to make them more drought tolerant, thus requiring less irrigation.

Oosterhuis showed the students technology designed to help cotton producers catch problems early and solve them. Displaying a sensor, he explained that farmers bury them in the soil where the equipment senses how much water is there. The infrared thermometer works similarly. It’s mounted on a pole and aimed at a crop to take its temperature.

In both cases, the information is transmitted to a satellite and retrieved by the farmer on a personal computer or cell phone. “You can see a graph of how wet the soil is or how warm the crop is getting. You can react with irrigation accordingly.”