Tree roots in the lawn?
Yes, you know - when a nearby tree has sent roots all the way across the lawn, and some of them are sticking up through the grass, causing anguish to the owner of the mower, as the blade goes "Scccrrrrrrrr!" every time they try to mow over the protruding root.
Here's one I was asked to deal with earlier this year: I forgot to take a proper "before" shot, so:
...here is the lawn with the scalped root protruding, with my secateurs for scale.
Take an edging iron or a small border spade (as I am using here) and cut a slot about an inch deep, in a square, all around the root. I have done three sides of the box here.
Do the same as when you want to lift a turf - having made the slot, push a small border spade under the grass, about an inch down, and slide it sideways under the grass, loosening the square of turf. Try to keep it all in one piece if you can.
Now you can tackle the root or roots - cut them off with loppers, digging around them with a small hand tool as necessary.
It doesn't hurt the tree to do this - if the roots are in your lawn, then by definition they are sufficiently far away from the tree that it will have many more to support it. Also, a root that has projected above surface level will be dry and possibly dead anyway: and one that has had a mower regularly scalping it will almost definitely not be of much use to the tree any more.
Right! All the roots are out, I have added in some soil to fill the hole I made, and trodden it down well so that it won't sink the next time someone walks or mows over it. Aim to make the ground slightly higher than the original ground level, just in case.
The next job is to get the watering can, and to make the newly-trampled soil good and wet, and to wet the underside of the lifted turf flap as well.
Then, turn the flap back over into place (cries of "Green side up!" from behind me) and tread it down well, then water it from above.
Job done! Here is the replaced flap - above - with my daisy grubber indicating where the root used to protrude. I added a small handful of grass seed to the hole, to encourage it to fill in as quickly as possible.