The present invention is directed to an applicator having an agricultural product pneumatic conveying system which meters particulate material from one or more source containers at the application equipment and transports the particulate material to evenly distribute the particulate material from the applicator. The pneumatic conveying system employs large diameter supply lines connected between the metering devices at the source containers and delivery nozzles, where the supply lines operate to move and mix the particulate material from the source containers to the nozzles. The particulate material is metered from the source containers into the supply lines via a number of airlocks that can be operated without allowing airflow from the large diameter supply lines to enter the source containers through the airlocks. In addition, the metering devices can b e operated in collective or independent variable manners to allow for sectional control and turning compensation.