|Holland, Marjorie M|
Submitted to: Society of Wetland Scientists
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2004
Publication Date: 4/5/2005
Citation: Kroger, R., Holland, M., Moore, M.T., Cooper, C.M. 2005. Nutrient through-flow and uptake in agricultural drainage ditches: The role of plants [abstract]. Southeastern Chapter of the Society of Wetland Scientists Abstracts. p. 10. Interpretive Summary:
Technical Abstract: Agriculture drainage ditches are primary intercept wetlands in the amelioration of nutrient pollution from agricultural fields. Drainage ditches, as integral components of the agricultural landscape remove surface runoff and act as major conduits of nutrients from agricultural lands to receiving waters. These ditches are prolifically abundant in wetland plants, providing additional surface area for microbial interactions as well as acting in a small, yet important assimilatory capacity. However, these assimilatory function is negated with seasonal die-back and the release of assimilated nutrients into the system in winter. The additional lack of cover, in a winter rainfall area also provides faster water movement to occur in the ditch. We tested the hypotheses of whether plants given the opportunity will firstly assimilate higher concentrations of nutrients, such as nitrogen and phosphorus, and whether with subsequent decomposition these concentrations are released back into the water column. Given the opportunity Leersia oryzoides, a dominant wetland ditch plant species, will assimilate significantly higher concentrations of nitrogen and phosphorus in above and belowground biomass. Subsequently, the senescence of aboveground biomass yields significantly higher levels of phosphorus and for a longer period of time. However, there were no significant differences in nitrate and nitrite levels which suggests that denitrification and microbial processes were removing these products from the system. Results to date suggest that decomposition occurred during summer, however it is expected that more decomposition takes place in late fall into early winter.