Define Compost Additives

Natural Compost Ingredients

• A variety of natural nitrogen and carbon ingredients are the surest way to a healthy compost. Nitrogen-based materials are typically fresh and juicy, like kitchen scraps, or of animal origin, such as feather, manure, and blood or bone meal. Green plant material, like grass clippings and seed-free weeds, are great sources of nitrogen, as are coffee grounds, tea leaves and lint from a clothes dryer. Carbon-based items are typically brown and woody, such as dried leaves, shredded paper and cardboard. Sawdust and wood chips are much richer in carbon and should be used sparingly in combination with other carbon-based materials. Stack alternating layers of carbon and nitrogen materials for the most effective compost pile.

Inoculants

• Inoculants are commercial products that contain cultures of dormant bacteria, enzymes and fungi. Adding these cultures increases the diversity and number of microorganisms living in the pile, which in turn speeds up the rate of decomposition. Compost piles with a variety of organic matter will have enough of these microorganisms because they're naturally occurring during the decomposition process. Inoculants may add different beneficial varieties and are often used in commercial composting. An alternative way to introduce microorganisms to the compost is to mix a few scoops of finished compost or garden soil into the pile.

Starters or Accelerators

• Commercially produced starters or accelerators are designed to jump-start the process of decomposition by adding nitrogen, enzymes and bacteria to the pile. Nitrogen decomposes more quickly than carbon, so the initial spike of accessible nitrogen can help the pile to start decomposing. Enzymes and bacteria are naturally occurring in decomposition and these types of additives are only helpful in new or stagnant compost piles. Finished compost or garden soil can similarly be used to introduce bacteria and enzymes to your compost pile.

Activators

• Activators are chemically synthesized nitrogen additives used to stimulate decomposition. Activators often contain sugar, which provides food for microbes. This type of additive is helpful if the compost has too much carbon -- more than 30 parts carbon to 1 part nitrogen. Organic alternatives include manure, blood meal or feather meal, which are all rich sources of nitrogen. If you're using synthetic nitrogen, avoid activators containing ammonium sulfate, which is toxic to earthworms. Use artificial nitrogen additives sparingly, as they lower the pH of the pile which can harm microorganisms and block aeration necessary for decomposition.