Nutrient Removal by Switchgrass Harvested for Biofuel Production.

Phosphorus and Potassium rate studies were established at Milan, Tennessee on sites testing low in both nutrients by Meh 1 soil test.   Plots were harvested annually (single harvest in late fall) for biofuel production.  Tissue samples were taken for elemental analysis.  Soil samples were taken to track changes in Meh 1 P and K over time. There was no Switchgrass Response to Applied P or K on “ Low to Medium Testing Soils at the Milan site. Luxury consumption of K does not appear to result in excessive K removal by matured Switchgrass harvested for Biofuel.  Both Applied P and K rates resulted in increased soil test levels relative to the check plot. Elevation in K soil test levels appear higher than might be expected for the rates applied. Removal of P and K and other measured nutrients appears to be very low relative to forages harvested for use as hay for animal consumption purposes.