, Farm Journal Seeds & Production Editor
It's elementary—modern corn production takes nitrogen (N). Still, says Greg Luce, technical product manager for Pioneer Hi-Bred, developing corn hybrids that require less of the necessary element is a very important target for his company.
"Years of nitrogen testing have shown us that hybrids typically respond to nitrogen similarly,” Luce says. "We're working hard to test hybrids in nitrogen-deficient conditions to determine if there are native differences in performance at low nitrogen levels. We are also looking at transgenic events that may lead to hybrids using nitrogen more efficiently.”
Pioneer research has shown that hybrids within the same maturity zone don't differ much with respect to N utilization. "Through extensive testing in low nitrogen levels, we do see some difference,” Luce says. For this research, scientists test hybrids in continuous corn blocks that are depleted of N for comparison purposes. "Rotation with legumes, such as soybeans, has been done for a reason, and soybeans do contribute to nitrogen the following year,” Luce notes.
Luce also believes there might be some connection between more N-efficient hybrids and drought tolerance. "Nitrogen moves with water, and in a drought the corn plant typically ‘fires up' and expresses signs of nitrogen deficiency,” he says. However, he cautions that "nitrogen-use efficiency and drought tolerance are very complex traits and there are many factors to consider that are unique to both.
"Pioneer is much further along in the ongoing development of more drought-tolerant corn, which has been a key target for over 50 years,” Luce says.
Pioneer is testing transgenic events that have shown multiple years of yield advantage in reduced-N environments. "It may be a decade before more nitrogen-efficient products are marketed, but there are some very promising things coming to help growers and the environment with regard to this kind of technology,” Luce says.