Nitrate-N load reduction measured in a central Iowa restored oxbow

Evaluation of nitrate nitrogen fluxes from a tile-drained watershed in central Iowa.

Nitrate N fluxes from tile-drained watersheds have been implicated in water quality studies of the Mississippi River basin, but actual NO3-N loads from small watersheds during long periods are poorly documented. We evaluated discharge and NO3-N fluxes passing the outlet of an Iowa watershed (5134 ha) and two of its tile-drained subbasins (493 and 863 ha) from mid-1992 through 2000. The cumulati...

Stimulating nitrate removal processes of restored wetlands.

The environmental and health effects caused by nitrate contamination of aquatic systems are a serious problem throughout the world. A strategy proposed to address nitrate pollution is the restoration of wetlands. However, although natural wetlands often remove nitrate via high rates of denitrification, wetlands restored for water quality functions often fall below expectations. This may be in p...

The conservation reserve in south-central Iowa

The saturation of N cycling in Central Plains streams: N experiments across a broad gradient of nitrate concentrations

We conducted NO3 – stable isotope tracer releases in nine streams with varied intensities and types of human impacts in the upstream watershed to measure nitrate (NO3 ) cycling dynamics. Mean ambient NO3 – concentrations of the streams ranged from 0.9 to 21,000 lg l NO3 – N. Major N-transforming processes, including uptake, nitrification, and denitrification, all increased approximately two to ...

A Plate Test for Nitrate Reduction.