CAREER: Mechanisms and control of nitrous oxide emissions from forage conservation

Kansas State University, Manhattan KS

Investigators

Abstract

Agriculture is a major industry in the United States contributing about $1 trillion to the Nation’s gross domestic product (GDP) in 2019. Agriculture is also a significant contributor to the global emissions of greenhouse gases (GHGs). It is the largest source of nitrous oxide (N2O), a GHG which is about 300 times as potent as CO2 at heating the atmosphere. However, the current N2O emission inventories from agriculture and farming operations, including ISO 14064 and USEPA Inventory of US Greenhouse Gas Emissions and Sinks, only track emissions from soil management, manure management, and field burning of agricultural residues. This CAREER project will focus on N2O emissions from forage conservations as an abundant and yet unaccounted source of N2O from agriculture and farming. Forages are plants or parts of plants that serve as feed for livestock. Forage conservation often relies on fermentation as lactic acid produced from fermentation works as a natural preservative for forage crops. However, microorganisms that produce GHGs can also thrive in conserved forages with preliminary studies by the Principal Investigator (PI) of this CAREER project showing the production of a significant amount of N2O from laboratory incubations of alfalfa, a widely used crop in forage conservation. Building upon the results of these preliminary studies, the PI of this CAREER project proposes to carry out an integrated laboratory and field research program to quantify N2O emissions in forage conservations and investigate the microbial processes that control such emissions. The successful completion of this project will benefit society through the generation of new data and fundamental knowledge to quantify, manage, and mitigate the emissions of a non-CO2 and more potent GHG such as N2O. Further benefits to society will be achieved through student education and training including the mentoring of two graduate students and two undergraduate students at Kansas State University. Forage conservation is a significant and understudied source of potent GHGs such as nitrous oxide (N2O) in agriculture and farming. The overarching goal of this CAREER project is to quantify and advance the fundamental understanding of the mechanisms of N2O emissions from forage conservation processes. The specific objectives of the project laboratory and field studies are to: (1) Quantify and probe the mechanisms of N2O emissions by microorganisms in forage conservations (Objective 1), (2) Develop new strategies to control and manage N2O emissions from forage conservations (Objective 2), and (3) Validate the findings from the lab experiments in field-scale experiments (Objective 3). The successful completion of this research has the potential for transformative impact. The integrated laboratory and field experiments could contribute to more accurate estimates of N2O fluxes from forage conservations at local, regional, and global scales. The microbiological investigations could produce new fundamental knowledge and open new avenues to develop more effective strategies and solutions to manage and mitigate N2O emissions from forage conservation processes. To advance the education and training goals of this CAREER project, the PI will work with K-State Research and Extension (the Kansas State University Agricultural Experiment Station and Cooperative Extension Service) to raise awareness of the environmental impact of GHGs produced from forage conservations among livestock producers through outreach and educational activities. In addition, the PI plans to 1) partner with Future Farmers of America (FFA) to develop a course module on GHG gas emissions and management in farming and livestock production for high school teachers who run FFA programs in rural Kansas and 2) work with the K-State Project Impact staff to encourage and recruit rural students to pursue graduate education in Environmental Engineering. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.