The Effect of Cover Crop Treatments and Drought on Soil Nitrification Potential

Open Access
Trolio, Jena M
Area of Honors:
Environmental Resource Management
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Jason Philip Kaye, Thesis Supervisor
  • Robert David Shannon, Honors Advisor
  • Jason Philip Kaye, Faculty Reader
  • Nitrification Potential
  • Nitrate
  • Ammonium
  • Cover Crops
  • Drought
  • Soil Nitrifiers
  • Soil Nitrogen Cycle
Humans have a significant impact on the global nitrogen (N) cycle, and have doubled the amount of relative nitrogen in the biosphere. The majority of this impact is due to agricultural systems. Shifts in modern agricultural production, especially increased synthetic fertilizer, have led to increased nitrification potential, or the rate at which ammonium (NH4+) is converted biologically to oxidized N, in soil. Increased soil nitrification rate can create an economic loss for farmers and have adverse effects on the environment when oxidized N is leached through the soil profile. Managing an agricultural system to suppress nitrification rates is favorable. Elements of agricultural systems such as the dynamics of soil nitrifiers, the environmental effects of climate change, and the expansion of cover crops as a tool for nutrient management have a large influence over the soil nitrification potential. Despite their vast importance, the interactions between these elements and the impact they have on nitrification potential are generally unknown. This project was completed in two portions, a field study and a laboratory study, to achieve a better grasp on the effects of cover crops and drought on soil nitrification potential and the dynamics of soil nitrifier microbial communities. Soil samples that underwent different cover crop and drought treatments were analyzed for their inorganic N contents and their nitrification potentials to determine if the treatments created any significant differences.