Nutrients for Soil
Just like you need nutritious foods to keep your body healthy, the nutrients in soil need to be replaced too. One way to do that is to compost. Composting means taking things like food scraps and yard waste (dead leaves, grass clippings) and piling them together. (This happens on its own in nature - think about dead trees in forests, etc.) Over time, a process called decomposing causes the scraps to break down and eventually turn into soil. The new soil can be added to existing soil. The compost soil is rich in nutrients that come from the decomposed plants.
There are four main ingredients of compost: Air, water, greens, and browns. You know what air and water are. But what are "greens" and "browns"? These are the materials that air and water turn into compost. Greens are leftover scraps of vegetables and fruits, green leaves, and manure from livestock, things that have not dried out yet. Greens have lots of nitrogen. Browns are dry plant trimmings, like dried leaves or wood chips. Browns have lots of carbon. Your compost pile should be made of half greens and half browns to successfully decompose into soil. By turning and watering the pile, you will give it the air and water it needs to break down the greens and browns. When you have these four ingredients, you have the best start for the decomposers that will break down the ingredients: Bacteria, fungi, and insects.