Except as provided for in §B of this regulation, a professional fertilizer applicator or trained employee shall obtain a soil test prior to any initial application of P2O5 and prior to any second application of nitrogen to a management unit. A soil test is not required if: The nutrient application is made for the purpose of establishing turf on bare ground; and The nutrient application is made in accordance with the seeding recommendations of the University of Maryland Extension (Maryland Nutrient Management Manual I-E2, COMAR 15.20.07.02): The land has been disturbed such as by construction or tillage; or A lawn patch product is used. If a soil test, that is not more than 3 years old, exists for the property, it shall be used to determine the appropriate P2O5 application. Section B of this regulation does not authorize a professional fertilizer applicator or a trained employee to apply fertilizer containing phosphorus to turf when over seeding without basing the application on the results of a soil test. Any subsequent fertilizer applications to the same management unit shall be based on the results of a soil test. Soil tests are valid for 3 years. The soil test shall be obtained from a laboratory which uses a method that is approved by the University of Maryland for use in Maryland. Soil tests shall be associated with individual properties or management units. The University of Maryland shall identify laboratories that follow the soil testing methods and procedures recommended for use in Maryland. Professional fertilizer applicators must convert the soil test value for phosphorus to the equivalent University of Maryland Fertility Index Value to determine the appropriate University of Maryland Extension recommendation for P2O5 (Maryland Nutrient Management Manual II-B, COMAR 15.20.07.02).