Yep, fertilizer. That stuff is nasty. It will eat spreaders too if you don't rinse them and treat them. I usually wash my equipment with normal dish soap and hot water, then I treat all the metal with Fluid Film. Been using that stuff for years on snowplows and undercarriages. Works great for anything that sees corrosion, even aluminum. It's a little messy when you have to "work on" the areas that have been sprayed. But it's non toxic and washes off with soap and water. It's Lanolin/Woolwax based. You can actually use it to soften your callused hands. An ounce of prevention.....um.....well you know the rest right?
