According to the Denver Post, lawns use 2 percent of all of the fossil fuels in the United States and contribute 10 percent of all air pollutants. Excessive use of chemical fertilizers can also lead to water quality problems, including algae blooms. Using organic fertilizers, instead of petroleum-based chemical fertilizers, can reduce fossil fuel waste, reduce the risk of excessive nitrogen and phosphorus runoff, and result in better soil and lawn health over the long term. You have a number of potential products when selecting an organic lawn fertilizer.
Manure is likely one of the oldest organic fertilizers. According to Lawn Care Guide, manures are one of the most practical organic fertilizers available. In addition to nutrients, manure helps add organic content to the soil that will help strengthen lawn roots and allow the grass to use more naturally occurring soil nitrogen. Over time, the buildup of organic material in the soil will allow more air to reach grass roots where naturally occurring nitrogen in the air can naturally feed the grass.
Compost is organic material that has been allowed to partially decompose into a soil-like substance. Compost is made by piling organic materials, like grass clippings, old leaves, manures, old plants and flowers, and vegetative kitchen waste, and allowing them to decompose naturally. As the pile decomposes, heat is generated that helps to kill potential plant pathogens and seeds. Compost has similar advantages to manure. It adds micro and macro nutrients to your lawn and helps to add organic material that will help allow the roots of the grass to extract more nitrogen from natural sources.
Commercial Organic Products
Commercial organic lawn products can use a variety of nutrients from organic sources. Organic lawn fertilizers can include composted materials similar to what is in home compost piles. They also may include blood, bone, feather, fish or seed meals to help create a consistent fertilizer with predefined quantities of macro nutrients. An advantage of a commercial organic product is that commercial products are finely powdered and can be watered into the lawn. Compost and manure may take some time to seep into the soil.
Refertilizing with grass clippings can help to return nitrogen t the soil that had been previously taken up by the lawn. The easiest way to use lawn clippings as an organic fertilizer is to use a lawn mower with a mulching blade. Mulching blades cut grass clippings into smaller pieces, thus allowing them to drop below the surface of the lawn and break down faster. Although you can simply leave clippings from nonmulching mowers on the lawn, if there are excessive clippings, they can be unsightly and may take longer to break down. In extreme cases, longer clippings may shade the lawn and adversely affect lawn growth.
Leaf litter from trees around the lawn can also be a good source of organic fertilizer. Leaf litter can either be composted or, in some cases, mown over with a mulching mower to help speed breakdown. Like lawn clippings, leaf litter is a good way to recycle nutrients taken out of the soil by nearby trees.