A system, an apparatus and a method for uniformly applying UAN fertilizing liquid to soil on farmland for the purpose of increasing crop yields. The system has an UAN sprayer distribution rail applicator apparatus which may be pulled behind a tow vehicle or pushed by a sprayer or fertilizer applicator. The atmospheric tank contains UAN fertilizing liquid which passes from a pump, through a safety shut-off valve, and through a turbine style flow meter. A safety bypass line is provided upstream of the flow meter to relieve unsafe hydraulic pressure back through a pressure-sensitive valve in the event that multiple control valves close simultaneously. Flow through this bypass line also provides mixing of the UAN fertilizing liquid during cold weather. Upon exiting the flow meter, the UAN fluid enters the center of a distribution rail assembly. Spray nozzles with individual automatic shut-off valves are spaced across the distribution rail assembly.