Current restoration efforts for the Chesapeake Bay watershed mandate a timeline for reducing the load of nutrients and sediment into receiving waters. The Chesapeake Bay watershed model (WSM) has been used for two decades to simulate hydrology and nutrient and sediment transport; however, spatial limitations of the WSM preclude edge-of-field scale representation of phosphorus (P) losses. Rather...

some contaminants associate with soil particles and, thus, their transport and fate in the environment is determined by the soil erosion processes. eutrophication, low oxygen levels and high nutrient (nitrogen and phosphorus) concentrations in reservoirs, canals and other water courses, is a common water pollution feature. phosphorus (p) is one of the major plant nutrients and also the major nu...

The semi-automated equipment purchased to cope with the increasing numbers of samples analysed by the Fertilizer Advisory Service Laboratory is described. Experiments used to evaluate the equipment and modifications to methodology are detailed, with specific reference to the determination of "extractable" aluminium and phosphorus in soils and total phosphorus in cane leaves. It was concluded th...

AGNPS, which is an agricultural non-point source pollution model, was used in combination with GIS tools to assess the feasibility of water quality effluent trading for phosphorus, in Morrow Lake sub-watershed, Kalamazoo, Michigan, USA. GIS software packages (Arc/Info and ArcView) were used to prepare data input for the model and post process the results. The sensitivity of AGNPS parameters was...

Treatment wetlands are increasingly needed to remove nitrate from agricultural drainage water to protect downstream waters, such as the Gulf of Mexico. This project sought to develop a new edge-of-field treatment wetland, designed to remove nitrate-nitrogen and enhance phosphorus removal by plant harvest and to monitor its effectiveness. A 0.10 ha wetland was designed and installed to treat sub...

A manageable, relatively inexpensive model was constructed to predict the loss of nitrogen and phosphorus from a complex catchment to its drainage system. The model used an export coefficient approach, calculating the total nitrogen (N) and total phosphorus (P) load delivered annually to a water body as the sum of the individual loads exported from each nutrient source in its catchment. The exp...

Mechanistic, predictive equations for phosphorus (P) transport in runoff from manure-applied fields constitute a critical knowledge gap for developing nonpoint-source pollution models. We derived two simple equations to describe the P release from animal manure during a rainfall event—one based on first-order P desorption kinetics and one based on second-order kinetics. The manure characteristi...

It is commonly assumed in the PV community that Auger recombination is the dominant loss mechanism in heavily phosphorusdoped emitters of industrial Si solar cells. Contrary to this assumption, we show in this work that most of the losses are caused by Shockley-Read-Hall (SRH) recombination via defect states introduced by inactive phosphorus. Using numerical device simulations, we successfully ...