Here is some advice from the Rodale Press on sustainable practices for your lawn.
If you’re looking for the best organic lawn fertilizer, look no further than the grass clippings and fall leaves dotting your backyard. Not only are they free, using them instead of commercial fertilizers that contain synthetic nitrogen and phosphorus could also save marine life in your community’s ponds and rivers. A new study offers the first evidence that banning homeowners from using phosphorus-based lawn fertilizers helps bring depleted waterways back to life. The research was published in the most recent issue of Lake and Reservoir Management.
Various state and local governments across the country have banned lawn fertilizers containing phosphorus, due to the wildlife-depleting algae blooms those fertilizers feed in nearby waterways.
Of course, minimizing the size of your lawn or having no lawn at all might be the greenest alternative. However, if still want to maintain a green lawn while keeping harmful chemicals out of our waterways and reducing carbon emissions, you can read more suggestions at http://www.rodale.com/organic-lawn-fertilizer.