Good on quitting chemical fertilizers. That junk runs off in the first rain and pollutes the local water ways and the ground water. Maynard has had to spend about $8 million dollars reducing our phosphorus output from our sewage treatment plant, and then we go using detergents and chemical fertilizers... Algae blooms then produce too much oxygen in the water, and this kills all the plants and the animals, which then rot which uses up the oxygen. It is a finely balanced thing, and we make it all haywire with our chemicals (which come from natural gas, and oil, by the way).
Composting your leaves and clippings and kitchen cuttings, etc. give you *free* fertilizer that stays put -- the nitrogen in
humus is not water soluble and so it keeps on building the nutrients in the soil over time. Also, the chemicals kill off the natural processes in the soil, and they actually leech out the minerals that are there naturally.
Organic methods are sustainable, free, and provides a much healthier environment.