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United States Department of Agriculture

Agricultural Research Service

Title: Changes in Sediment - Water Column Phosphorus Interactions Following Sediment Disturbance

Authors
item Smith, Douglas
item Pappas, Elizabeth
item Haggard, Brian
item Huang, Chi Hua

Submitted to: Ecological Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 24, 2005
Publication Date: August 31, 2006
Citation: Smith, D.R., Warnemuende, E.A., Haggard, B.E., Huang, C. 2006. Changes in sediment - water column phosphorus interactions following sediment disturbance. Ecological Engineering. Vol. 27, Issue 1, 31 August 2006, Pp. 71-78.

Interpretive Summary: Sediment phosphorus dynamics are a constantly changing group of parameters that control phosphorus concentrations in surface water. Removal of existing sediments and deposition of new sediments will change the chemistry that controls phosphorus transport in ditches, however these phenomenon are not well documented. This study was conducted to determine the impact of severe storms on sediment phosphorus dynamics in tile-fed drainage ditches within agricultural watersheds in northeast Indiana. Exchangeable phosphorus in ditch sediments ranged from 0.5 to 1.32 mg/kg. The equilibrium phosphorus concentration in sediments ranged from 0.02 to 0.11 mg/L. When comparing the equilibrium phosphorus concentrations with soluble phosphorus in ditch water, sediments acted as a sink for phosphorus in five of the seven sites monitored. Phosphorus buffering capacity of sediments ranged from 2.7 to 13.8, increases of four to ten times higher than the phosphorus buffering capacity observed at the same sites prior to sediment disturbance from the storms. Chemical amendments did not seem to induce tremendous changes in phosphorus kinetics. These data indicate that while chemical amendments can be used to reduce phosphorus transport in streams and ditches, this practice should be targeted to times of the year when they will be most effective. This research impacts land resource managers by demonstrating how storm events can impact nutrient transport in streams and ditches.

Technical Abstract: Sediment P dynamics are a constantly changing group of parameters that control P concentrations in surface water. Removal of existing sediments and deposition of new sediments will change the physiochemical parameters controlling P transport in ditches, however these phenomenon are not well documented. This study was conducted to determine the impact of severe storms on sediment P dynamics in tile-fed drainage ditches within agricultural watersheds in Northeast Indiana. Exchangeable P in ditch sediments ranged from 0.5 to 1.32 mg/kg. The equilibrium P concentration (EPCo) in sediments ranged from 0.02 to 0.11 mg/L. When comparing the EPCo with soluble P in ditch water, sediments acted as a sink for P in five of the seven sites monitored. Phosphorus buffering capacity of sediments ranged from 2.7 to 13.8 L/kg, increases of four to ten times higher than the P buffering capacity observed at the same sites prior to sediment disturbance from the storms. Chemical amendments did not seem to induce tremendous changes in P kinetics. These data indicate that while chemical amendments can be used to reduce P transport in streams and ditches, this practice should be targeted to times of the year when they will be most effective. This research impacts land resource managers by demonstrating how storm events can impact nutrient transport in streams and ditches.

Last Modified: 9/21/2014