Researchers look for strategies to reduce wheat yield gap

Posted March 22, 2017

by Hannah Schlapp, Kansas Wheat Communications Intern

Farmers aim to increase yield and profitability while maintaining stewardship of the land. With farming comes preserving the soil and being cautious in management practices to keep the ground functioning to its full potential. This may mean farmers change the way they apply certain fertilizers to the soil, as well as other crop production components. Researchers at Kansas State University are coming together to help farmers get a bigger bang for their buck by finding management practices that can increase yields and profitability while still preserving the land. These researchers include Romulo Lollato, wheat and forages production agronomist with K-State Research and Extension; Dorivar Ruiz Diaz, associate professor and nutrient management specialist in agronomy; Gary Cramer, assistant professor in agronomy; and Anserd J. Foster, an assistant professor and Southwest area extension agronomist. This project is under the direct administration of Brent Jaenisch, a M.S. student working in Lollato's program.

“There are many regions of the world where wheat yields are stagnant. In Kansas, we have had somewhat of an increase in the last 30 years, but it’s been at a relatively slow rate,” Lollato said, “However, after performing long-term research of the yield potential in the region, we have found that we have an exploitable yield gap that can be economically reduced through management, yield gap being the difference between what we produce now compared to what we could potentially economically produce.” 

Lollato has previously performed related research that shows a possibility for yields in central Kansas to increase about 10-20%, while still maintaining profitability and stewardship of the land. The next step of the research is to determined exactly which management practices should be improved to accomplish that. 

In addition, the research shows that there’s approximately a 30-35 bushels per acre yield gap between current yields and the yield potential, largely due to substandard wheat management practices. It is important to remember that only a fraction of this yield gap can be economically reduced, as reaching for the full crop's potential is often not economical. Lollato is hoping to develop cutting edge management practices that will help lower the yield gap.  

The main concept of this research is to perform intensive management practices on wheat, along with standard management practices to see how yield responds to the two practices. The intensive practices will include enhanced fertilization with nitrogen, chloride and sulfur, along with a change in crop production components including plant population density, fungicide applications and plant growth regulators. The standard management practices will be based on K-State fertility recommendations. The goal of the project is to yield 60 bushels per acre on the standard management practices and 100 bushels per acre on the intensive management practices.  

“We have a very low-input control, which is representing our average farmer, and then on the other extreme of things, we have a very high input crop where we have several improved management practices,” Romulo says, “We are then breaking down the production components into individual factors. We will have our very low-input control, and add those individual management practices to that one at a time.” 

They will also be removing the controls from the intensive management practice one at a time to see how the wheat reacts. 

By using this approach, Lollato and his team will be able to differentiate wheat yields resulting from intensive management practices, as opposed to those from standard management. They will also be able to find the influence from each practice to determine whether the practice is resulting in a higher grain yield or not. 

So far in the research, the team has found a few different factors that will help with management practices in future growing seasons. “What we have found so far is fungicide is what was really driving yields last growing season when we had the severe stripe rust infestation. We provided fungicide to our very low input practice, and it yielded the same as the high input practice. This is showing us a sustainable way to increase production, and that we don’t need to put everything out; we need to manage it according to the growing season,” Lollato says. 

The funding for this research has been provided by Kansas wheat farmers through the Kansas Wheat Commission’s two penny wheat assessment. Once the research is completed, the farmers will reap the benefits in more ways than one.

“We are trying to find ways that producers can have higher yields and increased profitability, while economically reducing the current yield gap and the environmental footprint of wheat production in Kansas,” Lollato says.

###