A mobile spraying plant (1) for spraying crops, comprising a tank (10), at least one nozzle (60) in fluid communication (70) with said tank (10), a controllable regulating valve (30) for regulating a flow of liquid between the tank (10) and said nozzle(s) (60), an electronic control unit (101) configured for controlling the degree of opening of said regulating valve (30) and comprising a calculation unit and a storage/register, and a flow meter (40) for determining the flow of liquid between the tank and said nozzle(s) (60) and configured for communicating with said electronic control unit (101), which spraying plant (1) also comprises a pressure transducer (200) configured for measuring the pressure on the nozzles (60) when the throughput is outside the area of functioning of the flow meter； which pressure transducer (200) is in communication with said electronic control unit (101)； and said electronic control unit (101) being configured for calculating a flow based on data (202) from said pressure transducer (200).
