A method for operating a spray fluid operation system for an agricultural sprayer, comprising - providing a spray fluid in a fluid reservoir ; - conveying a fluid comprising at least one of the spray fluid from the fluid reservoir and an additional fluid different from the spray fluid and provided in an additional fluid reservoir into a fluid flow system by a pump and control system , the fluid flow system comprising - a dispensing flow system comprising a dispensing device having a plurality of dispensing elements configured to dispense a first pumped fluid received from the pump and control system to a field, and - a backflow system fluidly connected to the fluid reservoir and configured to pipe second pumped fluid received from the pump and control system back to the fluid reservoir ; - determining a fluid level of the spray fluid in the fluid reservoir by a level measuring device ; - receiving measurement data in a control device , the measurement data being indicative of the fluid level determined by the level measuring device ; - generating the second pumped fluid by the pump and control system ; and - controlling, by the control device , allocation of at least part of the second pumped fluid according to an allocation ratio dependent on the fluid level to - a first return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir ; and - a second return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir . - providing a spray fluid in a fluid reservoir ; - conveying a fluid comprising at least one of the spray fluid from the fluid reservoir and an additional fluid different from the spray fluid and provided in an additional fluid reservoir into a fluid flow system by a pump and control system , the fluid flow system comprising - a dispensing flow system comprising a dispensing device having a plurality of dispensing elements configured to dispense a first pumped fluid received from the pump and control system to a field, and - a backflow system fluidly connected to the fluid reservoir and configured to pipe second pumped fluid received from the pump and control system back to the fluid reservoir ; - a dispensing flow system comprising a dispensing device having a plurality of dispensing elements configured to dispense a first pumped fluid received from the pump and control system to a field, and - a backflow system fluidly connected to the fluid reservoir and configured to pipe second pumped fluid received from the pump and control system back to the fluid reservoir ; - determining a fluid level of the spray fluid in the fluid reservoir by a level measuring device ; - receiving measurement data in a control device , the measurement data being indicative of the fluid level determined by the level measuring device ; - generating the second pumped fluid by the pump and control system ; and - controlling, by the control device , allocation of at least part of the second pumped fluid according to an allocation ratio dependent on the fluid level to - a first return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir ; and - a second return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir . - a first return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir ; and - a second return device (19; 20; 22; 23) connected to the backflow system and configured to return the second pumped fluid to the fluid reservoir . <EOS>