See more from this Session: Soil Testing and Plant Analysis
Monday, November 1, 2010
Long Beach Convention Center, Exhibit Hall BC, Lower Level
Phosphorus is an environmental concern because this P often promotes weed and algae growth in bodies of fresh water. The decomposition of the weed and algae material reduces dissolved O2 levels. This phenomenon can lead to odors, death of fish, and a general degradation of the aesthetic and recreational value of the. Point and non-point sources of P are of concern for the water quality monitoring, but the P outputs from a body of water are also important for a complete picture of a P budget. At Pewaukee Lake, near Milwaukee, Wisconsin, aquatic plant (weed) harvesting has been a consistent component of lake management. The plant material is then applied as a soil amendment. The impact of the harvesting, in terms of P removal, was determined in order to facilitate on-going P and plant monitoring. The plant material was collected at various locations and times and analyzed for total P. Phospho-molybdate colorimetric analysis followed P extraction. A comparison of two different extraction methods was made: a) by sulfuric acid digestion (wet digestion: Nelson, 1987) and b) by muffle furnace (dry digestion: Plank, 1992). With this data and the volume of harvested plant material, the P removal is calculated as a component for the P budget.