While yields improved somewhat in 2012 over the 2011 season, he said, the three commercially available corn hybrids thought to be top producers only averaged 100 bushels an acre in 2012. The primary reason was the expected seasonal rainfall of 10.5 inches didn’t materialize – less than 6 inches fell during the growing season, Marek said.
In spite of the results, the study was a success, Marek said. Not only did it disprove the capability of being able to sustainably produce 200 bushels per acre on such a limited-irrigation basis, it provided valuable data on limited irrigation water management and characteristic traits of the corn hybrids.
“We think this three-year 12-200 study gained us extremely valuable data regarding previously unknown data portions of the corn production function for the region,” Marek said. “Much of the characterization information regarding the specific varieties can potentially be related to other ‘families of corn hybrids’ and to those being developed.”
For instance, he said, the data gathered indicated that one of the varieties had a tendency to be a better forage variety than a grain-producing variety.
Several production management practices were determined as being key factors during the course of the study also, Marek said. They include:
- Irrigation depth per application generally should be increased to the point that application runoff either does not occur or is minimal to reduce soil evaporation losses, but should be limited to depleted water within the soil root zone profile.
- Upper soil profile cracking should be managed to the degree possible with irrigation applications and allow for maximum opportunity regarding rapid infiltration potential should a large rainfall event occur.
- Delayed corn planting should be implemented to shift the peak corn evapotranspiration requirement and to take advantage of reduced evapotranspiration requirements typical in the early fall period.
Marek said this study showed the potential range of climatic conditions that can and do occur in this region and how they can impact production.
“The policy and regulatory insight towards both the cost to producers and benefit to water conservation cannot be overstated,” he said. “The data derived from this and other similar research and demonstration efforts strongly support sensible groundwater regulations and rules of water conservation management, not only for the region but throughout the western U.S.”
Marek said more limited irrigation research is needed “as we utilize the Ogallala Aquifer to support our regional economy. Next, we should further study rainfall probabilities needed for sustained limited-irrigation corn production, since corn accounts for over 60 percent of the agricultural water used within the region.”