Simplify the following text for a Grade 8 native English-speaking person.
Original: Another environmentally-friendly or ecologically-friendly alternative is to lay tracks into grass turf surfaces ; this is known as grassed track ( or track in a lawn ) , first used in Liverpool in 1924 .
Simplified: Another environmentally-friendly or ecologically-friendly alternative is to lay tracks into grass turf surfaces . This is known as grassed track ( or track in a lawn ) .