Project Number: 5040-12630-006-27-R
Project Type: Reimbursable Cooperative Agreement
Start Date: May 1, 2017
End Date: Apr 30, 2020
Objectives: Specific objectives of the research include: (1) To conduct soil sorption studies to investigate how labile phosphorus sorption is affected by soil physical and chemical properties. (2) To evaluate existing soil phosphorus sorption models on their adequacy for describing the observed data. (3) Reanalyze historical data base of soil properties collected by Swedish University of Agricultural Sciences (SLU) for correlations between soil test phosphorus concentrations and soil physical and chemical properties.
Approach: Soil sorption studies: Changes in soil phosphorus concentrations following phosphorus application will be measured by mixing phosphorus solutions at varying concentrations with each soil. The soil/phosphorus mixture will then be shaken for 24 hours and the phosphorus concentration remaining in solution will be measured colorimetrically and by inductively coupled plasma optical emission spectroscopy. Statistical analyses will be performed to look for correlations between phosphorus sorption rates and soil properties such as soil texture, soil chemistry, and soil pH. Evaluation of existing phosphorus cycling models: Results from phosphorus sorption studies will be modeled using existing phosphorus sorption and cycling models. If these models are deemed to be inadequate, modifications to the existing models will be made. Reanalysis of historical database: Cooperator has collected soil samples from across Sweden and has measured soil test phosphorus concentrations as well as soil physical and chemical properties. These data will be statistically analyzed to determine if any correlations exist between soil physical and chemical properties and soil phosphorus cycling parameters such as the soil phosphorus sorption coefficient.