Dissertations and Theses @ UNI
Availability
Open Access Thesis
Keywords
Nitrates--Environmental aspects--Iowa--Black Hawk County; Soil pollution--Iowa--Black Hawk County; Nitrates--Environmental aspects; Soil pollution; Iowa--Black Hawk County;
Abstract
An environmental field study was conducted from April to October 1998 in the Black Hawk County, Iowa. The main goal of the study was to find an appropriate field method to enhance degradation of nitrates in the surficial soil. Seven different methods were developed in the study to compare between four variables. The variables that were investigated were the source of nitrates, the moisture content of the soil, the uptake by plants and the total carbon content of the soil. The investigation has also been conducted to find out the specific influence of each parameter on landuse. A weather station was set up in the field to monitor the climatic parameters and determine any correlation between those factors and degradation of nitrates at the top surface of the soil in short term. Soil samples were collected from 21 plots at two different depths (surface and 1 foot). The average sampling frequency was 7 days. Each sample was analyzed for moisture content of the soil and nitrate concentration. Ethanol was added as an additional carbon source to some of the plots. The excess ethanol appeared to have helped the nitrification process in the soil instead of the denitrification process. Ethanol seemed to have had a toxic effect on denitrifying bacteria. Even if the amount of added nitrogen was the same in all the plots, much higher nitrate concentrations were found in those plots that received chemical fertilizer compared to the ones that received organic fertilizer. This was due to two geochemical processes that were more vigorous in plots that received manure: ammonia volatilization and anoxic ammonia oxidation. The intermittent irrigation enhanced denitrification at the one-foot depth. The investigation showed that rain events helped nitrification on the surface and denitrification at the one-foot depth and that during dry periods nitrification was primarily non-existent. Finally, a short-term correlation was found between temperature and nitrate concentration in the surface samples.
Year of Submission
1999
Degree Name
Master of Science
Department
Department of Earth Science
First Advisor
Mohammad Z. Iqbal
Second Advisor
Alan C. Czarnetzki
Third Advisor
James C. Walters
Date Original
1999
Object Description
1 PDF file (123 leaves)
Copyright
©1999 Urko Atxotegi Alegria
Language
en
File Format
application/pdf
Recommended Citation
Alegria, Urko Atxotegi, "Field Methods to Enhance Degradation of Nitrate in Surficial Soils" (1999). Dissertations and Theses @ UNI. 1921.
https://scholarworks.uni.edu/etd/1921
Comments
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