Earth Sciences Commons^™

Nitrogen And Potassium Dynamics Of Selected Indiana Soils, Chun Zhao

Open Access Dissertations

Nitrogen (N) is the most limiting essential nutrient for crop growth. Numerous studies have been performed to improve N fertilizer recommendations. Accurate prediction of soil N supply has been found to be one of the most important factors that determine optimum fertilizer N rates. Seven soils collected from various locations across Indiana at four different depths were tested for N mineralization potential. Results showed that laboratory mineralizable N in the top layer (0-15 cm) of the seven soils ranged from 50 to 68 mg N kg-1 soil. In addition, more than 50% of the total mineralizable N was contributed from …

Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu

Open Access Dissertations

This study investigates wetland subsurface hydrology, as well as biogeochemistry - which is strongly influenced by water and temperature dynamics - as these interactions are expected to be highly significant, yet remain poorly represented in current ecosystem and climate models.

Northern wetlands have received widespread public attention due to steadily increasing summer mean global temperatures, extreme precipitation events and higher rates of natural greenhouse gas emissions, as well as the significant impacts on them due to human activities. The goal of my graduate research has been to improve quantification of the role of subsurface hydrology in northern wetlands by using …