Evaluation of nitrate in groundwater under long-term manure application
Date
2018-08-27
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Over-application of manure to agricultural fields can contaminate groundwater resources through the leaching of nitrogen below the root zone. The goal of this study was to evaluate the factors affecting the spatial and temporal distribution of nitrate in groundwater following 44 years of manure application. The sampling of 26 wells over an 18-month period revealed that nitrate concentrations ranged from <10 mg-N/L to 1350 mg-N/L and isotopic analysis of 15N-NO3 and 18O-NO3 showed that denitrification occurred in 16 well locations. Generalized additive mixed models (GAMM’s) confirmed that cumulative manure loading had the largest control on the current spatial distribution of groundwater nitrate, while a decrease in groundwater nitrate with sampling date and an increase with dissolved organic carbon (DOC) and were also significant relationships. Evidence for the leaching of nitrogen into groundwater was found in well locations where manure was applied within the past 16 years. The groundwater nitrate trends observed in this long-term study suggest that historical management practices will affect groundwater quality for many decades to come.
Description
Keywords
Nitrate, Groundwater, Manure application, Long-term study, Hydrogeology, Stable isotopes, Recharge, Denitrification
Citation
Kyte, E. (2018). Evaluation of nitrate in groundwater under long-term manure application (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32867