Principal investigator: Cynthia Kallenbach, Colorado State University
Associated with: USDA-NIFA
Soil nitrogen (N) limitations intensify drought-associated yield losses, yet resolving water and N co-limitation remains a challenge. Under low soil moisture, microbial-mediated N mineralization is constrained by reduced microbial access to carbon and nutrients required for microbial metabolic processes. Selecting cultivars with certain root exudation traits may alleviate microbial carbon and N constraints such that N mineralization can be relatively maintained under drought. Our project explores cultivar root exudate-microbial interactions as a potential mechanism for enhanced plant-available N under water stress conditions.
We are using a combination of metabolomics, metagenomics, microbial functional and nitrogen assays to:
- Characterize root exudation rates and chemistry across a spectrum of drought-tolerant and -susceptible wheat cultivars,
- Determine how root exudation rate and chemistry mediate the mechanisms that drive microbial N cycling and subsequently wheat N-uptake under drought vs. well-watered conditions and
- Evaluate if and how the microbial responses influencing N mineralization under drought tolerant root exudation are altered by prior exposure to long-term drought.