UNDERSTANDING AND PREDICTING THE IMPACT OF AGRICULTURE ON THE ENVIRONMENTAL INTEGRITY OF MANAGED WATERSHEDS
Location: Water Quality and Ecology Research
Title: Nutrient mitigation capacity in Mississippi Delta, USA drainage ditches
Submitted to: Environmental Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 17, 2009
Publication Date: July 24, 2009
Citation: Moore, M.T., Kroger, R., Locke, M.A., Cullum, R.F., Steinriede Jr., R.W., Testa III, S., Lizotte Jr., R.E., Bryant, C.T., Cooper, C.M. 2010. Nutrient mitigation capacity in Mississippi Delta, USA drainage ditches. Environmental Pollution. 158(1):175-184. DOI 10.1016/j.envpol.2009.07.024.
Interpretive Summary: Drainage ditches void of vegetation efficiently move water off the production landscape and into receiving aquatic systems. Unfortunately, this rapid transport can also result in significant amounts of nutrients being transported, which might harm plants and animals in rivers, lakes and streams. A study was done to compare the nutrient detention capacity of two ditches—one with and one without plants. Both ditches were able to reduce the concentrations of nutrients before they entered aquatic receiving systems, although the ditch with vegetation was not significantly better than the bare ditch.
Eutrophication and hypoxia within aquatic systems are a serious international concern. Various management practices have been proposed to help alleviate nutrient loads transported to the Gulf of Mexico and other high-profile aquatic systems. The current study examined the nutrient mitigation capacity of a vegetated (V) and non-vegetated (NV) agricultural drainage ditch of similar size and landform in the Mississippi Delta. While no statistically significant differences in ammonium, nitrate, or dissolved inorganic phosphorus mitigation between the two ditches existed, there were significant differences in total inorganic phosphorus (V:36% ± 4; NV:71% ± 4). However, both agricultural drainage ditches were able to mitigate nutrients, thus reducing the load reaching downstream aquatic receiving systems. Further studies examining ecosystem dynamics within drainage ditches such as sediment and plant nutrient partitioning, as well as microbial processes involved, are needed to provide a better understanding of natural nutrient variability, seasonality and flux.