A well balanced trailer with a tank 100 gallons? A gas powered pump and a wide spray bar should be fine. Trick will be balancing the trailer to minimize the work your z has to do
I just picked up an Older Hustler and I plan to use it in the ditches and maybe a sprayer. Looking at setup for a larger electric tank, mounting and such to make these 5 acres more tolerable. What ingenious ways have you come up with for spraying the lawn.
100 gal water would be 834 pounds of water plus trailer and sprayer and tank. That would be a bunch to pull with a zero turn of any kind I would think.