With Oklahoma wheat producers heading into another growing season, the bottom line will be on producers’ minds, and for many, that means focusing on yield. 
  
However, doing what it takes to boost the bushels can also lead to other important things, like increasing the protein content of a crop. The protein content of Oklahoma wheat crops can garner increased attention after an extended period of registering less than ideal levels. 
  
“Low protein wheat can create pricing and marketing challenges for everyone in the supply chain,” said Brian Arnall, Oklahoma State University Extension precision nutrient management specialist. “Perhaps even more concerning is that low protein is an indicator that nitrogen was limited during grain fill and therefore, a field’s maximum yield potential wasn’t achieved.” 
  
The good news for proactive producers is this is a fixable concern. Variety selection, growing environment and fertility all play major roles in driving up the protein content in a wheat crop. 
  
While some varieties offer higher protein, the differences among varieties can be overshadowed by the environmental conditions at different locations. 
  
Ideally, during grain fill, optimal conditions would include cooler temperatures and ample available moisture, which could positively affect yield but negatively impact protein levels in the crop. 
  
“Fertilizing with your normal nitrogen rate to achieve your yield goal usually provides an adequate protein content as well,” Arnall said. “We can get the opposite, as well, especially with drought or other stresses, where there are less kernels and/or the kernels become small and shriveled. Now you have that same amount of nitrogen but less grain to put it in. So, you might actually have a higher protein content.” 
  
That leaves fertility, or more specifically nitrogen, as the X factor. Protein is a function of nitrogen concentration, and if the nitrogen concentration in grain is low, so is protein. 
  
“If the nitrogen well is running dry at the end of the season, protein will be low,” Arnall said. “We typically see low values if nitrogen rates were below crop need, or perhaps, the nitrogen applied was lost through leaching or other mechanisms, which is more likely to happen when all of the nitrogen is applied pre-plant.” 
  
Bottom line? Managing nitrogen and maximizing yield come down to ensuring nitrogen is available to the plant at important growth periods. 
 
“It’s always best to apply nitrogen when the plant needs it, which is right after tillering for grain-only. In dual purpose, we have a high need in the fall and again at tillering,” Arnall said. 
  
Producers do not need to guess about the nitrogen levels in their fields either. N-Rich strips, used in conjunction with the GreenSeekerTM hand-held sensor technology and a sensor-based nitrogen rate calculator, are key tools producers can use to guide them on nitrogen application. 
  
Ultimately, the goal is to enhance the overall quality of the Oklahoma wheat crop, Arnall said. 
  
“If we all work on improving protein and quality, we’re going to raise the overall quality of the Oklahoma wheat crop, and we’re going to have end users who want to buy this grain first before any other,” he said. 
 
For more information on nutrient management, download the free OSU report Applying Nitrogen Rich Strips and OSU fact sheet Evolution of Reference Strips in Oklahoma. 
  
Producers can also visit the Down and Dirty with NPK blog or contact the nearest county OSU Extension office.