Plants deplete nutrients from soil while they grow. The 13 mineral nutrients in the soil are dissolved in water and absorbed through a plant's roots. There are not always enough of these nutrients in the soil for a plant to grow healthy. This is why many farmers and gardeners use fertilizers, to add nutrients to the soil.

Chemical and synthetic fertilizers are intense and short lasting. If too much is applied it can actually harm the plant by “scorching” the plants roots. Unnatural fertilizers don’t help improve soil overall health or life span, which limits their long-term effectiveness. The nutrients they provide are quickly drained away into nearby waterways.

The natural nutrients from mature composts are released to plants slowly and steadily. The benefits last for longer than one season. It stabilizes the volatile nitrogen of raw materials to form large protein particles when composting, which reduces the loss of nitrogen.

Compost soil helps soils hold more plant nutrients by improving the Cation Exchange Capacity (CEC) and Anion Exchange Capacity (AEC) or exchange positive and negative charged ions, respectively, between a neutral atom. This allows nutrients to have stronger bonds with the soil, preventing them from being washed away.

Studies have shown that composts are able to help fight the spread of plant disease (e.g., Pythium root rot, Rhizoctonia roots rot chili wilt and parasitic nematodes) and decrease the losses of crops. Micronutrients and other critters in compost soil help to breakdown undesirables and toxins that cause plant disease into harmless and consumable materials.

Compost increases quality of soil structure, air flow, and water content leading to quicker establishment of new vegetation and decreases erosion rates. Compost protects the soil's surface from wind and water erosion by decreasing the action of soil dispersion by raindrops beating against the soil, increasing the infiltration rate, as well as reducing water runoff and increasing the surface wetness. It is vital to prevent erosion to safeguard waterways as well as maintain the efficiency and quality of the soil.

Using compost soil in landscaping and gardening increases the grounds ability to retain water by 2.5 times. Using compost soil reduces periods of water stress on plants and lessens the amount of water needed for healthy lawns, gardens, and houseplants.

If a soil becomes too basic or too acidic, plants can suffer from nutrient deficiencies or nutrient toxicities. Soil with a neutral pH level helps prevent plants from consuming environmental toxins, like lead and other heavy metals.

Compost reduces the soils bulk density and improves soil structure directly by loosening heavy soils with organic matter. Becuase of this, integrating composts into compacted soils can improve root penetration and turf growth.