A system comprises a distribution boom, a first pump device configured to provide a flow stream of a carrier substance for the distribution boom, a second pump device configured to supply a chemical substance into the flow stream of the carrier substance, and a control module. The distribution boom includes a plurality of boom sections. A boom section includes one or more dispensers, a mixing device configured to provide a combination of chemical and carrier to the one or more dispensers, and a control valve configured to supply the chemical substance to the mixing device. The control module is configured to individually control a rate of supply of the chemical substance to the boom section by the control valve.