The research team proposes an integrated set of investigations into the mechanistic basis of variation in yield as a function of nitrogen (n) in maize and sorghum

The Department of Energy Advanced Research Projects Agency awarded Colorado State University a $6.75 million Cooperative Agreement on March 17, 2026, under the Advanced Research Projects Agency - Energy program (CFDA 81.135) to conduct integrated investigations into the mechanistic basis of nitrogen use variation in maize and sorghum.

The research team will conduct annual field experiments across U.S. production environments using elite breeding and experimental genetics to identify how root system size, morphology, and root-associated microbiome partnerships—all genetically controlled traits—affect nitrogen uptake and crop yield under low-nitrogen and cold-soil conditions. Work includes comparative modeling of nitrogen responses between maize and sorghum, DNA and RNA sequencing to measure microbiome features through quantitative genetic methods, and development of breeding strategies to create hybrid lines with improved nitrogen use efficiency. The research aims to reduce nitrogen fertilizer use and associated N₂O greenhouse gas emissions by 50 percent consistent with program objectives.

Performance occurs at Fort Collins, Colorado, with a period of performance from March 17, 2026, through March 16, 2030. Colorado State University's Sponsored Programs division serves as the recipient, functioning as the research arm of the university's land-grant institution.

These include annual field experiments across US production environments using a combination of elite breeding and experimental genetics. Hypotheses regarding mechanisms will be informed by comparative modeling of the responses to n between maize and sorghum. Roots are a key breeding target for plant performance at limited n. The size and morphology of root systems affect n uptake from the soil and these traits are controlled by genetics. Like root size and morphology, crop traits controlling root-associated microbiome partnerships, which are crucial for crop nitrogen acquisition, are genetically controlled and can be improved through breeding. Therefore the same quantitative genetic methods used for breeding plant traits can be applied directly to microbiome features, which will be measured through DNA and RNA sequencing. Our findings will provide the genetic understanding to produce optimal root systems under low n and in cold soils. The use of relative variation in these mechanisms among the elite breeding genetics will allow US to quickly breed for improved nitrogen use under limited fertilization. This will facilitate the creation of hybrid lines that can be quickly brought to market and deployed in the field to reduce n fertilizer use and concomitant N2O greenhouse gas emission by 50% in line with program objectives.