| |3 to 10% by dry weight||ASTM F1647, Standard Test Methods for Organic Matter Content of Athletic Field Rootzone Mixes. | | |3 to 10% by dry weight||ASTM F1647, Standard Test Methods for Organic Matter Content of Athletic Field Rootzone Mixes. |
− | ![[Phosphorus]] (plant available, or extractable) | + | ![[Phosphorus]] (plant available, or extractable soil phosphorus) |
− | |12 to 40 ppm||As measured by the 'Olsen' method for alkaline and calcareous soils (common in Ontario). Alternatives include 'Mehlich I or III', or 'Bray', better suited to acidic to slightly alkaline and non-calcareous soils. NB: Results from the different test methods are not directly comparable.<ref>Sawyer JE, Mallarino AP. Differentiating and Understanding the Mehlich 3, Bray, and Olsen Soil Phosphorus Tests 1. http://www.agronext.iastate.edu/soilfertility/info/mnconf11_22_99.pdf. Accessed August 1, 2017.</ref> | + | |12 to 40 ppm||As measured by the 'Olsen' method for alkaline and calcareous soils (common in Ontario). Alternatives include 'Mehlich I or III', or 'Bray', which is better suited to acidic to slightly alkaline and non-calcareous soils. NB: Results from different test methods are not directly comparable.<ref>Sawyer JE, Mallarino AP. Differentiating and Understanding the Mehlich 3, Bray, and Olsen Soil Phosphorus Tests 1. http://www.agronext.iastate.edu/soilfertility/info/mnconf11_22_99.pdf. Accessed August 1, 2017.</ref> |