Changes

The Olsen method is recommended as the default to use for typical Ontario soils <ref>Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). 2006. Soil Fertility Handbook. Publication #611. Toronto, Ontario.</ref>. Calcareous soils are mostly or partly composed of calcium carbonate (i.e., lime or limestone). The Olsen extraction method should be used if the soil contains more than 2% calcium carbonate <ref>Frank, K., Beegle, D., Denning, J. 2012. “Phosphorus” In Recommended Chemical Soil Test Procedures for the North Central Region. North Central Regional Research Publication No. 221. Missouri Agricultural Experimental Station.</ref>

The Olsen method is recommended as the default to use for typical Ontario soils <ref>Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). 2006. Soil Fertility Handbook. Publication #611. Toronto, Ontario.</ref>. Calcareous soils are mostly or partly composed of calcium carbonate (i.e., lime or limestone). The Olsen extraction method should be used if the soil contains more than 2% calcium carbonate <ref>Frank, K., Beegle, D., Denning, J. 2012. “Phosphorus” In Recommended Chemical Soil Test Procedures for the North Central Region. North Central Regional Research Publication No. 221. Missouri Agricultural Experimental Station.</ref>

For [[green roof media]], the Saturated Media Extract (SME) method should be used <ref>Green Roofs for Healthy Cities. 2011. Advanced Green Roof Maintenance: Participant’s Manual. Toronto, ON.<ref>. In this extraction procedure, a sample of the media is saturated with deionized water containing a small amount of Pentetic acid (DTPA) to enhance extraction of micro-nutrients Warnacke, D. 1995. “Recommended Test Procedures for Greenhouse Growth Media.” In J. Thomas

For [[green roof media]], the Saturated Media Extract (SME) method should be used <ref>Green Roofs for Healthy Cities. 2011. Advanced Green Roof Maintenance: Participant’s Manual. Toronto, ON.</ref>. In this extraction procedure, a sample of the media is saturated with deionized water containing a small amount of Pentetic acid (DTPA) to enhance extraction of micro-nutrients Warnacke, D. 1995. “Recommended Test Procedures for Greenhouse Growth Media.” In J. Thomas

Sims and A. Wolf, eds., Recommended Soil Testing Procedures for the Northeastern United States. Northeast Regional Bulletin #493. Newark: Agricultural Experiment Station, University of Delaware.</ref>. This SME procedure should also be used to measure concentrations of [[soluble salts]] and [[nitrogen]] in green roof growing media.

Sims and A. Wolf, eds., Recommended Soil Testing Procedures for the Northeastern United States. Northeast Regional Bulletin #493. Newark: Agricultural Experiment Station, University of Delaware.</ref>. This SME procedure should also be used to measure concentrations of [[soluble salts]] and [[nitrogen]] in green roof growing media.