You should mulch your lawn.
Mulching your lawn after mowing or leaving grass clippings on the lawn after mowing provides the lawn with essential and natural nutrients and promotes a healthy lawn.
The mulched grass clippings will decompose on the lawn and release nutrients such as potassium, phosphorus and nitrogen back into the soil and act as a natural fertilizer for the lawn which helps keep the lawn green and healthy.
Mulching your lawn also improves the soil health and helps to retain the soils moisture which helps improve the soils structure and leads to a healthier and more vibrant lawn.
The mulch layer of the lawn also helps to suppress weed growth by blocking out sunlight and smothering the weed seeds.
Mulching the lawn also helps to eliminate the need to bag of and dispose of any grass clippings which also saves you effort and time.
Mulching your lawn also reduces waste by recycling the nutrients and minimizing the need for any synthetic fertilizers and landfill space.
And the moisture that is retained in the soil from mulching the lawn is also very beneficial during dry periods and drought.
And the mulching of the lawn also helps to insulate the soil and protect it from extreme temperatures.
I always mulch my lawn and have less need for fertilizers and the lawn stays nice and green and healthy.