Spoon-Feeding Nitrogen Shows Benefits

Lizzy SchultzAg Group, agronomy, Crop Protection, Nitrogen

Pivot Irrigation in Tassled Cornfield Experts at The Fertilizer Institute, as well as decades of research and practical experience, have concluded that matching nitrogen application to plant uptake can help to minimize nutrient loss, maximize utilization and improve plant performance and yield, and the increased move towards late-season nitrogen application, ­­­a best management practice for corn production today, has led to significant discussion about the optimum timing of later-season applications and the best ways to apply needed nitrogen.

Researchers at the University of Missouri have found that corn yields always improve when nitrogen is applied as late as tasseling, but the question of “how late is too late?” still remains to be answered.

“Researchers agree that a positive response to nitrogen application is seen when nitrogen is applied around the time of tasseling,” says Erik Tribelhorn, CEO of Agri-Inject in Yuma, Colorado. “The corn plant, however, takes up 20% of its total nitrogen after R2.”

IPNI Growth Stage N Uptake Better Crops Graph 1 Tribelhorn noted that the difficulty in addressing the late-season need most efficiently is that most application systems can’t operate much beyond the tasseling stage. Corn growers with pivot irrigation systems can work through this issue by utilizing fertigation, spoon-feeding nitrogen to the corn crop throughout the entire period of nutrient uptake. This avoids the peaks and valleys inherent in other application methods.

“Corn plants don’t eat nitrogen—they drink it,” Tribelhorn points out. “It makes sense to feed the plant at the same time it is taking up water. With today’s injection systems, you can precisely match the level of nitrogen delivered to the needs of the corn plant throughout its entire life cycle.”

Tribelhorn made a point to note that nitrogen is not the only nutrient that can be spoon-fed to the corn crop through fertigation.

“More than half of a corn plant’s sulfur uptake, for example, occurs after VT/R1,” Tribelhorn says. “As a result, many farmers will apply 28-0-0-5 through their pivots during the critical late stages of grain fill.”