Agricultural chemical export dynamics in a watershed

Nitrogen Balance in and Export from an Agricultural Watershed

Surface water nitrate (NO~-) pollution from agricultural production is well established, although few studies have linked field N budgets, NO~loss in tile drained watersheds, and surface water NO~loads. This study was conducted to determine field sources, transport, and river export of NO~from an agricultural watershed. The Embarras River watershed at Camargo (48 173 ha) in east-central Illinoi...

A stream's role in watershed nutrient export.

T he small watershed concept developed by Bormann and Likens (1) is a powerful means to understand how watershed ecosystems function (2–4). The approach requires estimating both element inputs to a watershed (e.g., atmospheric deposition, weathering) and outputs, usually via the stream that drains the watershed. Outputs are calculated as the product of stream water element concentration and str...

Kinetics and Modeling of Dissolved Phosphorus Export from a Tile-Drained Agricultural Watershed

Agricultural runoff can be a source of P, a limiting factor for freshwater eutrophication. To develop a simple method to estimate P export from the cropland, we studied 1.2-p.m filtered dissolved phosphorus (DP) output from four tiles draining areas ranging from 8 to 25 ha, and from a river draining a 48 173 ha watershed in eastcentral Illinois during 1993 to 1996. The land was under maize (Zea...

Predication of sediment delivery ratio in a small agricultural watershed

Phosphorus export from an agricultural watershed: linking source and transport mechanisms.

Many source and transport factors control P loss from agricultural landscapes; however, little information is available on how these factors are linked at a watershed scale. Thus, we investigated mechanisms controlling P release from soil and stream sediments in relation to storm and baseflow P concentrations at four flumes and in the channel of an agricultural watershed. Baseflow dissolved rea...