The growth of the hypoxic ‘dead zone’ in the Gulf of Mexico in recent years has placed increased focus on potential sources of nutrient pollution, with most of the focus being placed on watersheds where practices, including fertilizer application and land alterations combine to increase non-point source runoff. In this study, nutrient concentrations in surface waters of altered and unaltered areas of the Cache River Watershed, Arkansas, were compared to determine if agricultural land usage was responsible for the majority of nutrient inputs. Results suggest that for dissolved nitrites and orthophosphates, agricultural (altered) sites contribute significantly more than relatively unaltered sites but that for dissolved nitrates, unaltered sites have a large contribution to overall nitrate concentrations, particularly in late summer and fall months.
Kilmer, M. K.; Poe, N.; Chappell, S.; and Bouldin, J. L.
"Natural Nutrient Sources in the Cache River Watershed, Arkansas,"
Journal of the Arkansas Academy of Science: Vol. 69
, Article 14.
Available at: http://scholarworks.uark.edu/jaas/vol69/iss1/14