How is a compost bin considered self-sustaining?

Answer 1

That it breaks down materials in one form so that they can be used in another accounts for one reason why a compost bin is considered self-sustaining. A compost bin contains materials, such as kitchen scraps and yard debris, that no longer can or will be used in their existing forms and that may be carted off to landfills or recycled on location into soil amendments, fertilizers and mulches. It discourages additional efforts and expenses off location and, by transforming trashable materials into soil food web enhancers, encourages a continuous cycle of plant growth, product harvest, recycling as compost, plant growth, etc.

Answer 2

That it breaks down materials in one form so that they can be used in another is one reason why a compost bin is considered self-sustaining. Specifically, the compost bin takes materials that no longer can or will be used in their existing forms. For example, compostable materials include certain kitchen scraps and yard wastes such as fallen leaves and grass clippings.

Such compostable materials can be carted off to landfills or they can be used on location. On location, they can be used as mulch, natural fertilizer, and soil amendments. So the use of compostable materials, and their being turned into compost, discourages additional expenses and efforts off location.

Additionally, the use of compostable materials and of the end product as compost encourages a continuous cycle of plant growth, product harvest, recycling as compost, plant growth, etc. So it's a self sustaining cycle that the compost bin enters and perpetuates through its recycling of otherwise trashable materials.

Answer 3

A compost pile is not self-sustaining as it requires human effort to apply material for composting and to remove the prepared compost.