EAPSI: Contributions of microorganisms to greenhouse gas emissions from volcanic soils prevalent in the Pacific Rim Region

Giguere Andrew, Corvallis OR

Investigators

Abstract

Soils derived from materials of volcanic origin (e.g. Andisols) play an especially important role in Japan, the United States and other countries around the Pacific Rim with volcanic activity. In Japan, Andisols comprise a large fraction of the agricultural soil resource. Andisols have a large influence on human activities on the Pacific Rim. They are often located in regions with high population density, and have high agricultural productivity. Andisols have unique physical and chemical properties not found in other soil types. This research will examine how the chemical and physical properties of cropped and noncropped Andisols influence the nitrogen (N) cycle and greenhouse gas emissions. This research will be conducted in collaboration with Dr. Yuichi Suwa at Chuo University. Dr. Suwa's laboratory has more than 20 years of experience examining nitrogen cycling, and has the resources necessary to conduct this research. Nitrification is an important part of the global nitrogen cycle in which ammonium (NH4+) is oxidized to nitrate (NO3-). The oxidation of NH4+ is the rate-controlling step of nitrification and is carried out by ammonia-oxidizing bacteria (AOB) and archaea (AOA). Nitrification may promote N loss from terrestrial environments that otherwise would be available to plants. The process of nitrification can lead to loss of N as nitrous oxide (N2O) which is a potent greenhouse gas with 350 times the warming potential of carbon dioxide (CO2), and its concentration is increasing. The process of nitrification is especially important in soils that are heavily impacted by human activities. This study will examine how the nitrification activity and N2O emissions from AOA and AOB in allophanic and nonallophanic Andisols respond to changes in conditions of NH3 availability, O2 tension, and water content. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.