On the soil test reports, the amount of phosphorus extracted by the Mehlich-3 extractant will be approximately 1.5 times to twice the amount extracted by Mehlich-1. For the other plant nutrients, the two extractants will extract about equal amounts. It is not recommended that this information be used to derive Mehlich-1 based recommendations with Mehlich-3 extractant results or vice versa. These are only rough comparisons and do not apply to all soil types.
Back to the main page.