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Pushing the Upper Limits of Corn Yield University of Nebraska. Lincoln, NE (September 2002) - Understanding the biological underpinnings of yield should help farmers boost yields, stay competitive, protect the environment and meet projected demand for corn. To do that, University of Nebraska agronomists in 1999 launched the Ecological Intensification Project. The comprehensive, long-term study explores the most cost-effective, environmentally friendly ways to achieve yields usually seen only in yield contests. "Corn average yields throughout the state are only about half of what we think the biological yield potential is in terms of genetics, climate and soils," said Achim Dobermann, an Institute of Agriculture and Natural Resources soil scientist and project coordinator. "If we want to stay competitive in the long run, we must learn how to consistently grow these crops at 70 percent to 80 percent of their true yield potential," he said. "This will increase profitability and perhaps have positive effects on the environment if nutrient-use efficiency can be increased." Statewide corn yields average about 150 bushels per acre. Researchers think true yield potential for eastern and central Nebraska is closer to 300 bushels per acre. During the study's first three years, the highest yields were consistently 250 to 260 bushels per acre in drip-irrigated plots. "We can get 250 to 260 bushels per acre regardless of climatic variability among years," Dobermann said. That's less than originally expected because high nighttime temperatures during grain fill hurt yields the past two years. Plant distribution also wasn't as precise as it could be. As part of this project, researchers are examining a multitude of yield-influencing factors, including soil fertility, carbon sequestration, nitrate leaching and soil microbial function. They're conducting similar research on soybeans. By year's end, they'll create a map of yield potential and optimum planting dates for Nebraska using climate and research data. This map will show producers how planting date and hybrid choice influence yield potential by region. Within three years, scientists will combine yield results with findings from an IANR soil fertility project to revise corn nutrient management recommendations, emphasizing efficiency for elevated yields. Researchers hope to create better crop-growth models, including planting dates, crop densities and nutrient requirements, to help farmers maximize yields. Existing models underpredict yields in better growing environments such as Nebraska, said Ken Cassman, agronomy and horticulture department head and project leader. The government someday might pay farmers for carbon sequestration on their land, he said. "If you underestimate yield, you underestimate the amount of carbon that may remain in the soil, which could cost farmers money." Better management also has environmental benefits. Fine-tuning inputs means fewer chemicals to run off or leach into water. Cropland that traps more carbon may help reduce the buildup of carbon dioxide, a major greenhouse gas. Through research, we can create the most environmentally friendly production systems in the world," Cassman said. "This could lead to branding Nebraska products as environmentally friendly, which would add value. Good management could help Nebraska producers be competitive in global markets where environmental issues are increasingly important." Producing more corn when prices are low may seem a bad idea, but higher yields could be pivotal to long-term viability for crop producers and global food security, Cassman said. "Economists who watch global markets say U.S. corn and soybeans will remain a crucial component for food security in coming decades," he said. Thanks to excellent soils, Nebraska can more easily meet environmental standards than can competitors like Brazil where soils are poorer. "We can't take our eyes off the ball. Right now production costs in places like Brazil are lower, but their production costs will rise faster than ours." Higher yields through intensive management, guided by improved understanding of yield potential and input requirements, also should help farmers maximize shorter term profits, Cassman said. The Nebraska Corn Board, Foundation for Agronomic Research, Potash and Phosphate Institute and Fluid Fertilizer Association help fund this research. Contact: Communications Specialist (402) 472-5755 |