SPRINGFIELD Ill. — With funding from the Illinois Nutrient Research and Education Council, researchers from the University of Illinois have shown the relationship of in-season soil nitrogen concentration with corn yield and potential nitrogen losses.
What the researchers learned and amplified was the benefit of incorporating risks of environmental N losses when developing new approaches for more sustainable nitrogen management.
The research results in a peer-reviewed paper “Relationship of in-season soil nitrogen concentration with corn yield and potential nitrogen losses” have now been published in the Soil Science Society of America Journal.
The research focused on measuring soil mineral nitrogen throughout the growing season on 32 field plots scattered around Illinois. Researchers identified a critical level of SMN and correlated that with optimized yield and potential nitrogen losses. Essentially, they learned:
• Critical level of SMN that optimized yield decreased 2.6-fold between the V5-V7 and VT-R1 growth stages, but was stable between the V8 and V16 growth stages.
• Plots with SMN at critical levels yield 22% more than those with SMN below critical levels.
• Increasing SMN levels to those required to optimize yield also increased the probability of N losses.
• The stability of SMN levels during the time of rapid N uptake shows the importance of mineralized N to the plant.
“A great learning experience is that we are able to ask simple questions and test simple ideas when working with multiple locations across years. This research represents a step in balancing the need for improved production while limiting environmental impacts,” said Giovani Preza-Fontes, a Ph.D. candidate in Crop Sciences at the University of Illinois and co-author of the article with Emerson Nafziger, Laura Christianson and Cameron Pittelkow.
“The researchers are honing in on answering the question ‘when is enough nitrogen at precisely the right time going to yield greater yields, but not contribute to nitrogen losses to the environment,’” said Ed Corrigan, who heads NREC’s research committee and serves as vice chairman on the NREC board.