Nutrient Content at the Sediment-Water Interface of Tile-Fed Agricultural Drainage Ditches

Abstract

Extensive network of tile drains present in the Midwest USA accelerate losses of nutrients to receiving ditches, rivers and eventually to the Gulf of Mexico. Nutrient inputs from agricultural watersheds and their role in affecting water quality have received increased attention recently; however, benthic sediment-nutrient interactions in tile-fed drainage ditches is still a matter of active research in consideration to nutrient discharge from tile drains. In this study, phosphorus (P) and nitrogen (N) contents and variability of nutrient retention ability of benthic sediments upstream and downstream from tile drain outlets were evaluated in managed agricultural drainage ditches in Indiana. Sediment samples were collected every three months upstream and downstream from selected tile drains in three ditches in northwest Indiana. Sediment equilibrium P concentrations (EPC0) were measured to examine P adsorption-desorption and equilibrium characteristics of benthic sediments in the ditches. P sorption index (PSI), exchangeable P (ExP), and exchangeable NH 4 + -N (ExN) were measured to evaluate nutrient retention ability and readily available nutrient content of benthic sediments. Results indicated a dynamic interaction between benthic sediment and overlying water column where sediments were acting as a sink or a source of P. There were no differences in nutrient retention ability between sediments collected upstream and sediments collected downstream from the selected tile drains. While the data, except for ExN, was comparable to reported values by previous studies in Indiana's drainage ditches, there was no particular seasonal pattern in the content of exchangeable nutrient content in sediments at all three sites. This study also OPEN ACCESSWater 2010, 2 412 suggested that nutrient uptake by benthic sediments in these drainage ditches is not always efficient; therefore watershed management should focus on minimizing the delivery of nutrients into ditches while maintaining their drainage functionality.

Estimation of annual baseflow at ungauged sites in Indiana USA

“…Most of Indiana is dominated by extensive networks of tile drainage systems, which are generally artificial channels more directly linking agricultural fields to naturally occurring streams or rivers than natural overland and subsurface flow pathways (Smith and Huang, 2010;Ahiablame et al, 2010Ahiablame et al, , 2011. Construction of tile drainage systems in the region began in the second half of the 19th century (David et al, 1997;Richards et al, 2002).…”

Seasonal water quality changes in on-farm water storage systems in a south-central U.S. agricultural watershed

“…Over the past decade, many researchers have investigated the role of ditches as an individual structural BMP because of their crucial function of linking agricultural watersheds to external ecosystems (Herzon and Helenius, 2008;Ahiablame et al, 2010). Dollinger et al (2015) collated the vast majority of scientific contributions focused on the benefits of implementing ditches for agroecological management.…”

Determinants of spatio-temporal variability of water quality in the Barotse Floodplain, western Zambia

“…Wetlands or fl oodplains are widely regarded as important locations for the uptake and transformation of nutrients and sediment in fl uvial landscapes . Research by Ahiablame et al (2010) describes sediments as probably the most infl uential determinant of the ability of the system to process and sustain nutrient loads. This is because fl oodplains are frequently thought of as sinks of inorganic nutrients and sources of organic nutrients -in other words, nutrient transformers .…”