It’s common for Iowa farmers to apply manure to their fields in the fall. It’s a valuable and environmentally friendly fertilizer source.

But its also a process often misunderstood by non-farmers. That’s why Muscatine County Farm Bur­eau members Mike Deahr and his son, Ryan, invited their county supervisors to their farm to demonstrate the family’s new dragline manure application system.

The system, the Deahrs said,...