Toadstools are nature's recyclers feeding on dead or rotting vegetation. Your toadstools will be a result of rotting wood or similar in the lawn and under the path. The only way to permanently get rid of them will be to dig up the rotting vegetation... Sorry...
We had a real problem with a carpet of them about 3 x 10 feet and also scattered elsewhere. Dig them up and pour a jug or 2 (enough to saturate the area) of boiling water in the hole. It slows them right down and we get them rarely now.