Drainage Control to Diminish Nitrate Loss from Agricultural Fields

Abstract

In an attempt to reduce NO3−‐N movement to drainage waters, flashboard riser‐type water level control structures were installed in tile mains or outlet ditches at two locations to raise the water table to increase denitrification during the winter. A large reduction in NO3−‐N movement through tile lines occurred (from 25–40 to 1–7 kg/ha) in moderately well‐drained soils because of reduction in effluent volume. In the moderately well‐drained soils, there was no indication of increased denitrification in the field. In poorly drained soils, drainage control had no influence upon soil profile oxidation‐reduction potentials but resulted in approximately.a 50% reduction in NO3− movement through drainage ditches. This reduction was due to increased water movement into and through deeper soil horizons (below 1 m). The NO3−‐N concentrations and low Eh values in all profiles below 1 m indicate that the NO3− which moved to this depth underwent denitrification.

RZWQM simulated effects of crop rotation, tillage, and controlled drainage on crop yield and nitrate-N loss in drain flow

“…Similarly, a comparable amount of N was lost in lateral seepage as in drain flow (Wahba et al, 2001). Although N concentrations were significantly lower with CD compared to FD in some studies (Drury et al, 1996;Mejia and Madramootoo, 1998;Wahba et al, 2001), reduction in N losses to drain flow was mainly due to reduction in drain flow under CD as the reduction in N concentrations was not significant (Gilliam et al, 1979). Our simulation results also showed no consistent decrease in overall N concentration in drain flow under CD (Tables 3 and 4).…”

“…Since controlled drainage has shown promise in reducing subsurface drainage discharge and nitrate-N loss in drainage water (Gilliam et al, 1979;Wahba et al, 2001;Wesstrom et al, 2003;Khan et al, 2003), in this study, we also tested controlled drainage effects on crop production and N loss in drain flow by assuming a drainage-control system managed as follows: control gate at 120 cm on March 15; raise to 60 cm on June 10; lower to 120 on September 10; raise to 30 cm on November 1; and lower to 120 cm on March 15, based on controlled drainage studies in the literature (Kalita and Kanwar, 1993;Drury et al, 1996;Wesstrom et al, 2003). This drainage-control system minimized nitrate-N losses in the winter, yet it optimized crop yield and water quality objectives during the cropping seasons (Kalita and Kanwar, 1993).…”

Drainage and Water Quality in Great Lakes and Cornbelt States

“…Reducing nitrate concentrations in drainage waters may be possible by enhancing denitrification (Burford and Bremner 1975;Davenport et al 1975;Meek et al 1969), and watertable management in the southeastern U.S. has shown potential for reducing nitrate concentrations in subsurface drainage water (Gilliam 1987;Gilliam and Skaggs 1986;Gilliam et al 1979;Skaggs and Gilliam 1981). These studies clearly establish a precedent for reducing contamination through manipulating biological functions via water-table management.…”

Using AnnAGNPS to Predict the Effects of Tile Drainage Control on Nutrient and Sediment Loads for a River Basin

“…In Ontario, Canada, it is estimated that 1.6 million ha of crop land is tile drained (Sunohara et al, unpublished data, 2014). Tile drains are efficient pathways by which contaminants from agricultural fields can enter the broader surface water environment (Gilliam et al, 1979;Kladivko et al, 1991;Drury et al, 1996;Gentry et al, 1998;Geohring et al, 1999;Baker, 2001;Lapen et al, 2008;Frey et al, 2012). Inputs of agricultural contaminants from field to stream can be substantial in tile-intensive landscapes where tile flow occupies a significant proportion of total stream flow.…”

“…Simulation results were compared with monthly direct runoff estimated from observed discharge, TSS, total N, and total P data collected at the Plantagenet gauging station. Based on availability and integration of observed data, the respective calibration and validation periods were 1971-2000-2005for direct runoff, 1973-1979and 1980-1983for TSS, 1977-2000for total N, and 1977-1990-1993 for total P. Calibration and validation were performed assuming UCTD conditions because CTD was, and is currently, an extremely uncommon practice in the basin. Three performance criteria were used to evaluate the goodness-of-fit among observed and modeled outputs: the Nash coefficient of efficiency (E) (Nash and Sutcliffe, 1970), the RMSE-observations standard deviation ratio (RSR), and the PBIAS (Gupta et al, 1999).…”