A Pilot landing at a non towered airport reported taking evasive action on landing roll to avoid a lawnmower on the runway.

Narrative

I was returning to ZZZ from ZZZ1. I departed ZZZ1 VFR northwest bound to ZZZ. I checked the weather and NOTAMs prior to my departure; noting only 2 NOTAMs for ZZZ. They were both UAS (Unmanned Aircraft System) NOTAMs; one active and one scheduled in the future. In flight; I received the ZZZ AWOS and noted the winds were calm and opted to use RWY XX as there was a firefighting TFR approximately 2.5 nm northwest of the airfield. After clearing the ZZZ2 Class D airspace at 8;500 MSL; I began a descent and communicated to ZZZ CTAF I was navigating for a Left Base RWY XX. I noticed an ADS-B target about 1;000 feet below me that appeared to be heading toward ZZZ; so I changed the plan and decided to enter the Traffic Pattern using the standard 45* entry to the left downwind. I made the radio call to ZZZ CTAF about my new plan and I began navigating for that standard Traffic Pattern entry while scanning for the previously mentioned traffic that was now overtaking me.As I spotted them (a firefighting aircraft inbound to the TFR northwest of ZZZ); I noticed another ADS-B target opposite direction about 500 ft below me; opposite direction; and began scanning for that aircraft as I was almost at the point of my 45* entry to the left downwind at ZZZ. After passing the second aircraft; I was entering the ZZZ Left Downwind at midfield for RWY XX at 6;100 MSL; I made a radio call to ZZZ CTAF about my traffic pattern entry. I continued in the pattern configuring my aircraft for landing and running my before landing and landing checklists. I turned Left Base for RWY XX with another CTAF call. I turned Final with another CTAF call and executed my landing. As I touched down and began my roll out I noticed some dust kicking up about 1/3 down the runway and realized it was a lawnmower moving northwest (away from me) along the edge of the runway. I immediately noticed the lawnmower turn left onto the runway. It was too late for a go around and I immediately drifted off the center line away from the lawnmower. As soon as the lawnmower saw me; they turned back off the runway into the grass and continued their mowing operation. After shutdown; I double checked the NOTAMs; there were only the 2 UAS NOTAMs previously mentioned. There was no ALL SFC WIP GRASS CUTTING NOTAM issued for ZZZ and the AWOS had no mention of it. Additionally; whoever was mowing the grass was not making radio calls and I assume wasn't monitoring the CTAF. The lawnmower had no lights. I probably should've been able to see the lawnmower when I entered the downwind; however; my attention was divided between looking for the firefighting traffic and slowing/configuring/navigating my aircraft into the downwind. I never really scanned the airport surface for traffic since no one else had been on the CTAF making any calls and I didn't see any ADS-B traffic in the pattern or around ZZZ since I was over ZZZ2. When I was on final; I probably should've been able to see the lawnmower; but I was hyper focused on nailing my landing as I was attempting a spot landing. Corrective actions for me would include a more thorough traffic scan of not only the pattern; but the airport surface. Corrective actions for the airport would be to issue a NOTAM for grass cutting; have the lawnmower monitor CTAF; and have aviation safety lights on the lawnmower.