| Phosphorus has been named the leading contributor to eutrophication internationally. Recently the focus has shifted from phosphorus loss in runoff and erosion to the phosphorus remaining within the soilscape and its potential to leach into the surrounding watershed. This is especially important when dealing with agricultural watersheds where phosphorus is applied in the form of fertilizer. In the research area presented in this paper, the water quality within the watershed is a great concern. This project involves soil samples taken from an agricultural land in Ohio to determine the ammonium oxalate extractable phosphorus, aluminum, and iron. These chemical properties were related to the phosphorus sorption capacity to determine the degree of phosphorus saturation (DPS). Phosphorus inputs and outputs over 72 years were related to the DPS. The amount of ammonium-oxalate extractable P found within the soilscape was compared to the P balance, with consideration for natural P levels and previous fertilizer applications. |
