A disbursement system for an unmanned aerial vehicle, the disbursement system comprising a plurality of disbursement nozzles operable to dispense a flowable product at variable flowrates; a flow controller responsive to instructions (146, 150) and operable to regulate a volume of the flowable product dispensed by the plurality of disbursement nozzles by changing a flowrate of one or more of the disbursement nozzles, either collectively or individually; and a control system including a plurality of sensors operable to monitor respective values of a plurality of flight parameters of the unmanned aerial vehicle; and a processing unit configured to model an effect of the plurality of flight parameters on first flow control instructions corresponding to a prescription coverage of the product and model a change in the flowrate of the one or more of the disbursement nozzles, which change in flowrate is modeled as a first constant multiplied by a value of at least a first one of the plurality of flight parameters, wherein a respective sensor of the plurality of sensors is operable to monitor a value of a second one of the plurality of flight parameters and the change in flowrate is modeled as a sum of the first constant multiplied by the value of the first one of the plurality of flight parameters and a second constant multiplied by the value of a second one of the plurality of flight parameters; and, optionally, the sensor is operable to monitor a value of a third one of the plurality of flight parameters and the change in flowrate is modeled as a sum of the first constant multiplied by the value of the first one of the plurality of flight parameters, the second constant multiplied by the value of the second one of the plurality of flight parameters, and a third constant multiplied by the value of a third one of the plurality of flight parameters. a plurality of disbursement nozzles operable to dispense a flowable product at variable flowrates; a flow controller responsive to instructions (146, 150) and operable to regulate a volume of the flowable product dispensed by the plurality of disbursement nozzles by changing a flowrate of one or more of the disbursement nozzles, either collectively or individually; and a control system including a plurality of sensors operable to monitor respective values of a plurality of flight parameters of the unmanned aerial vehicle; and a processing unit configured to model an effect of the plurality of flight parameters on first flow control instructions corresponding to a prescription coverage of the product and model a change in the flowrate of the one or more of the disbursement nozzles, which change in flowrate is modeled as a first constant multiplied by a value of at least a first one of the plurality of flight parameters, wherein a plurality of sensors operable to monitor respective values of a plurality of flight parameters of the unmanned aerial vehicle; and a processing unit configured to model an effect of the plurality of flight parameters on first flow control instructions corresponding to a prescription coverage of the product and model a change in the flowrate of the one or more of the disbursement nozzles, which change in flowrate is modeled as a first constant multiplied by a value of at least a first one of the plurality of flight parameters, wherein a respective sensor of the plurality of sensors is operable to monitor a value of a second one of the plurality of flight parameters and the change in flowrate is modeled as a sum of the first constant multiplied by the value of the first one of the plurality of flight parameters and a second constant multiplied by the value of a second one of the plurality of flight parameters; and, optionally, the sensor is operable to monitor a value of a third one of the plurality of flight parameters and the change in flowrate is modeled as a sum of the first constant multiplied by the value of the first one of the plurality of flight parameters, the second constant multiplied by the value of the second one of the plurality of flight parameters, and a third constant multiplied by the value of a third one of the plurality of flight parameters.