Date of Award
Program or Major
Master of Science
William H McDowell
The effect of NO3- deposition on NH4 +, DON, and DOC retention as well as abiotic NO3 - retention via the hypothesized "ferrous wheel" mechanism was examined in oxic and anoxic tropical and oxic temperate soils using sorption isotherm experiments. Adsorption of NH4+, DON, and DOC by mineral soils was examined in forest floor extracts with DOC levels of 0-50 mg/L. Experimental treatments included no added NO3-, 4mg/L of added NO3-, or 4 mg/L of NO3 - and 2 mg/L of Fe3+. Ferric iron was added since it would likely increase DOC retention in the context of podzolization, and it might also influence N retention. Retention of NH4 + and DOC did not change upon NO3- addition in any of the soils. Although there are some experimental conditions that could be changed, the results indicate that the ferrous wheel hypothesis does not explain the NO3- retention by mineral soils that has been observed in the field. (Abstract shortened by UMI.).
Watanabe, Naoko, "Abiotic retention of nitrogen and dissolved organic matter by forest mineral soils" (2006). Master's Theses and Capstones. 213.