Loam Sweet Loam: A General Assessment of Microbial H₂ Metabolism Kinetics in Central New Jersey Agricultural Soils

Abstract

"Human land use, primarily through farming and its resulting land disturbances impacts the soil sink of atmospheric hydrogen maintained by soil microbial communities; this thesis’ aim is to assess, both through measurements of soil H2 uptake rate and bacterial genomics, what governs this rate. Genetic assessment shows that soils grown under different crops at the same site retain similarity in community diversity and hydrogen uptake, but undisturbed soils even as little as 20 meters away show much greater uptake of hydrogen, which appears to be attributable to soil organic carbon (SOC) loss through disturbance. Some preliminary data points to soil nitrogen, in particualr ammonium modulated through N fixers like soybeans and other legumes, as an equally significant contributor to hydrogen uptake as SOC, but the sample size of this was small. Questions of human impacts on atmospheric cycling remain to be answered in this case of trace gas sources and sinks, which this thesis only scratches the surface of."