The present invention is directed to a spray system for an agricultural machine in which multiple spray nozzles for spraying a liquid product can be dynamically arranged in number and location along a preconfigured rail acting as a boom. Each spray nozzle can include an attachment arrangement for conveniently attaching, tightening, loosening and/or detaching the spray nozzle with respect to the rail. In one aspect, the attachment arrangement can comprise a fastener configured to tighten or loosen a clip with respect to a body for engaging the rail. A separate product line for supplying liquid product to the spray nozzles can flexibly include numerous ports, more than there are spray nozzles, with some ports attaching to spray nozzles via branch lines, and other ports being sealed to inhibit flow.