Agricultural practices and nitrate pollution in ground water in the Central Valley of Chile
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Robert C. Golembeski (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
Abstract: Nitrate contamination of groundwater is an issue of global concern.
Anthropogenic fixation of nitrate has increased exponentially in the last century
and the over-application of nitrogen fertilizer is currently the largest intrusion into
the nitrogen cycle. Previous studies have determined that various regional
conditions can contribute to the level of nitrate contamination in groundwater. In
addition to chemical and physical conditions, fertilizer application rates and overirrigation
can serve as compounding factors. This study attempted to analyze the
previously mentioned conditions by monitoring nitrogen concentrations in ground
water from sampling wells in the Central Valley of Chile over a 13-month period.
Samples were collected monthly and nutrient concentrations were analyzed. In all
wells, concentrations of nitrate and nitrite were determined to be well above the
established MCL?s for each and a general trend was observed in the
concentrations that correlates to seasonal changes in land-use practices. A field
experiment was conducted to reduce fertilizer application rates and irrigation
water volumes applied to test fields by deploying an experimental fertilizer/
irrigation system. Data from the sampling wells associated with the test fields
shows a substantial decrease in nitrate and nitrite concentrations in the groundwater.
Furthermore, when the experimental system was combined with improved
water delivery methods (medium-volume furrow flooding and low-volume drip
irrigation) a decrease in water volumes and fertilizer application rates of up to
two? thirds was obtained without affecting crop yield rates. Results of this study
suggest that the over-application of fertilizer and irrigation water reported in
previous studies are in fact areas of concern and that a link exists between ground water recharge and irrigation volumes. It is further suggested that long-term
application of the experimental system is necessary to prove its benefits to the
agricultural, ecological, economical, and scientific communities. If the
performance record for this device can be repeated under a variety of conditions
its role in reducing global intrusions to the nitrogen cycle would be substantial.
Agricultural practices and nitrate pollution in ground water in the Central Valley of Chile
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Created on 1/1/2009
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science
- Language: English
- Date: 2009
- Keywords
- Groundwater--Pollution--Chile--Central Valley, Nitrates--Enivronmental aspects--Chile--Central Valley
- Subjects
- Groundwater -- Pollution -- Chile -- Central Valley
- Nitrates -- Enivronmental aspects -- Chile -- Central Valley