Sticks, walnuts, pine cones and blades

Do small sticks, pine cones, walnuts, dull the blades much? Probably some, but there is a limit to how much of this stuff one can pick up!!!
There are a few surface roots that I hit at times by accident too.

They sure will. Grass will dull the blades over time. I run 3 sets of blades on my zero turn and change them out often. I keep sticks picked up all the time. Someone on here said they had not sharpen there blades in 3 years and they were fine. Ya I don't think so. They were dull.

I got several walnut trees in the yard but one of them went bonkers this year. I use the snow blade on one garden tractor and push them in a pile then I shoveled 14 heaping loads on my garden tractor trailer. Wish some logger would offer me anything for that tree.

They will dull a blade the worst thing is wire. I mow the village cemetery all that wire from the plastic flowers makes my blades look like a serrated knife.

That was probably ME that ran my Cub Cadet zero turn blades THREE YEARS before sharpening. Mower is now running it's seventh summer, sharpened the blades last year, 2021. I bought a new set last spring so I can put sharp blades on and get mowing, sharpen the old blades when I have time. I balance and clean them to bare steel when I sharpen them.
The blade RPM is so fast on this zero turn a 1 inch round bar would cut the grass. I still have three IH Cub Cadet garden tractors, 2 38 decks and a 50 inch deck. When that was all I had to mow with I was sharpening blades every 2-3 weeks. The tips of the blades wore in an arc, more wear on the tip, in fact, All the wear was on the tip.
These 7 year old zero turn blades still have straight cutting edges, just like factory, just a tic over 300 hours on it. Considering almost all the cutting is done by the tip of the blade, it's amazing how these blades wear so well. I'D say MTD understands metallurgy and heat-treatment really well! OR they farm it out to a local company started by a University of Wisconsin professor that does special hardening processes. They make a lot of special thrashing rotor parts for Case IH, a Certified Supplier to them in fact.
I got fed up with the poor mowing performance of my IH Cub Cadet 38 mowing decks, I made a bunch of changes to the deck housing and improved the cut quite a bit, but still not as good as a Simplicity deck. I've got my 2nd 38 deck about ready to start welding on. I've never had a 42 deck, I imagine they don't cut real great, just a 38 deck with one inch longer outer blades. The 44 & 50 inch decks are much improved, I've had both. I mowed with a 44 deck for 15 years, yards from 2.3 acres to about 4 acres, with a second tractor with a 38 inch deck. I sharpened the 44 blades every 3-4 mowings, just a light touch-up, I never replaced those blades in all those years and all those acres. And I have a new set of 50 inch blades I haven't taken out of the box because the zero turn mows so much better and faster, and uses less gas.
I check the blade sharpness every time I mow before I mow, the right rear tire leaks down, stinking tubeless tires! Discharge chute is right there, I check the blades after I air up the tire.
I tried a couple sets of IH Hard Coated mower blades. I NEVER found the longer lasting claim to be true, just much more money for nothing.
I had a buddy try a set of Meg-Mow blades on his 317 Deere with 48 deck, a round plate with 4 free swinging blades shaped like sickle mower sections, think he's gone back to stock blades.
But anyhow, before you say something isn't true, why don't you check it out in person?

I have a 60 zero turn. I know all about blade tip speed. Mowing a lot of grass over 3 years the blades are dull. You are tearing the grass not cutting it. Just because there are no nicks in the blade doesn't mean it's sharp. You will never convince me blades stay sharp for 3 years.

It depends on how much you use the mower, and the terrain. Years mean nothing, hours of use mean everything. We noticed a big difference moving from N MN to the St Cloud area that is very sandy, blades didn't last very long.

Well his post said yards of 2.3 to 4 acres. Even much less than that and blades won't stay sharp for 3 years. I will say it again, just because blades look ok doesn't mean they are sharp and they will just tear the grass and not cut it.

Sticks and walnuts don't seem to bother mine ? However get too close to the gravel driveway and that tears them up. As does mowing along the edge of the road and hitting a speaker magnet ! Makes a heck of a noise only way I knew what it was a piece of it was still stuck to the deck.

You can look at the blades of grass and tell they have been cut, not ripped off.
You only know a fraction of what you think you know.

Good idea with the blade

Dr. Evil my yard (lawn) is 5 acres. I keep it impeccably nice. I know all about how grass looks with sharp blades and dull blades. If you're zero turn blade tip speed is so fast that a 1 inch rod would cut the grass then why do you even change blades or ever sharpen them at all? Go talk to some professional landscapers and lawn care companies. Telling me I know a fraction of what I know shows your ignorance. Just keep mowing your grass with your dull 1 inch rod on your zero turn.

Just another note Dr Evil, blade speed is measured in FPM not RPM as you stated. You know a fraction of what you think.