Changes

For BMPs including: [[Bioretention]],[[Enhanced grass swales]],[[Vegetated filter strips]], [[Absorbent landscapes]], [[Green roofs]] and, bulk materials including:[[Compost]], and [[Topsoil]], phosphorus (P) should be measured as extractable phosphorus. Extractable P is the portion that is easily available to organisms like plants and algae (i.e., available) that are present in the environment and is the measure of immediate concern to water quality.

For BMPs including: [[bioretention]], [[enhanced grass swales]], [[vegetated filter strips]], [[absorbent landscapes]], [[green roofs]] and, bulk materials including: [[compost]], and [[topsoil]], phosphorus (P) should be measured as extractable phosphorus. Extractable P is the portion that is easily available to organisms like plants and algae i.e. is the measure of immediate concern to water quality.

The quantity of extractable P is determined through acid or base extraction of a sample and testing the concentration in solution by a soil testing laboratory. Commonly used extraction methods on soil samples are the Bray and Kurtz P-1 procedure for non-calcareous soil (Bray and Kurtz, 1945) or the Sodium Bicarbonate (Olsen) method for calcareous soil (Olsen et al., 1954). The Sodium Bicarbonate (i.e., Olsen) method is recommended as the default to use for typical Ontario soils (OMAFRA, 2006). Calcareous soils are mostly or partly composed of calcium carbonate (i.e., lime or limestone). The Sodium Bicarbonate (Olsen) extraction method should be used if the soil contains more than 2% calcium carbonate (Frank et al., 2012). Modern and acceptable procedures for both types of extractions are provided by North Central Regional Research Publication No. 221 (Frank et al., 2012).

The quantity of extractable P is determined through acid or base extraction of a sample and testing the concentration in solution by a soil testing laboratory. Commonly used extraction methods on soil samples are the Bray and Kurtz P-1 procedure for non-calcareous soil (Bray and Kurtz, 1945) or the Sodium Bicarbonate (Olsen) method for calcareous soil (Olsen et al., 1954). The Sodium Bicarbonate (i.e., Olsen) method is recommended as the default to use for typical Ontario soils (OMAFRA, 2006). Calcareous soils are mostly or partly composed of calcium carbonate (i.e., lime or limestone). The Sodium Bicarbonate (Olsen) extraction method should be used if the soil contains more than 2% calcium carbonate (Frank et al., 2012). Modern and acceptable procedures for both types of extractions are provided by North Central Regional Research Publication No. 221 (Frank et al., 2012).