Keeping phosphorus in line

Phosphorus runoff and leaching to surface water is a growing concern. Research from PACE Turf and others suggests that older phosphorus sufficiency guidelines may be too high, and that phosphorus use can be reduced with little or no impact on turf quality.

The term phosphorus saturation index (PSI), sometimes also known as the phosphorus saturation ratio (PSR), has been used to determine the risk of phosphorus surface runoff or phosphorus leaching through the soil to drain. The formula that we…