The deep and extensive root systems of several varieties of cover crop can break surface and subsurface compaction, allowing your cash crop deeper root systems, as well as plants with less water and fertilizer needs.
Many species of cover crop introduce a high amount of organic matter into the soil. Additional organic matter can increase water holding capacity and improve healthy microbial activity.
Cover crop can help to prevent loss of valuable and fertile topsoil.
Some species of cover crop are highly effective in recycling nutrient through the soil. When these crops are terminated, many of the nutrients leech back into the soil. Certain species free up things like nitrogen, or various micronutrients.
The very act of rotating crops can work to reduce the pressure of disease. Additionally, certain species of cover crop are natural biofumigants.
Cover crop, when healthy, possesses the capability to suppress weed growth.