Commercial lawn fertilizer applicator licenses shall be issued subject to the following conditions which shall be specified on the license form.
   (A)   Random sampling. Commercial lawn fertilizer applicators shall permit the city to sample any commercial lawn fertilizer or other chemical application to be applied within the city at any time after issuance of the initial license.
   (B)   Possession of license. The commercial lawn fertilizer application license or copy thereof shall be in the possession of any party employed by the commercial lawn fertilizer applicator when making lawn fertilizer or other chemical application within the city.
   (C)   State regulations. Licensee shall comply with the provisions of the Minnesota Fertilizer and Soil Conditioner Law as contained in M.S. Chapter 18C, as it may be amended from time to time.
   (D)   Sign. A state approved universal sign, no less than three inches by three inches and attached to a wire or stick not less than 12 inches in height shall be placed on the lawn after application of the lawn fertilizer or other chemical and shall remain there at least for 48 hours. The sign shall state, to the effect: Warning - lawn fertilizer or other chemical has been applied to this lawn by - followed by the name of the licensee.
(`89 Code, § 140.030)