Soil is a complex mixture of weathered rock and mineral particles, the living organisms of the soil food web and the decaying remains of plants, animals and microorganisms. Good garden topsoil is typically about 45 percent mineral particles, 25 percent air, 25 percent water and 5 percent organic matter. Soil scientists have identified more than 70,000 kinds of soil in the U.S. based on the many different combinations of mineral particles – sand, silt and clay – and various amounts of organic matter and nutrients. Gardeners must determine the texture, structure and pH of a give soil to properly identify its makeup and type. In doing so, exploring the characteristics of soils in the region can provide helpful insights into creating sustainably designed and maintained home gardens.
International Year of Soils – The Soil Science Society of America is coordinating with the Global Soil Partnership and other organizations around the world to celebrate the 2015 International Year of Soils. Learn more…
How They Compare
|Unsustainable Landscape||Sustainable Landscape||What Can I Do?|
|Soils are often over-compacted, which restricts the infiltration of rainwater and inhibits plant growth
Earthworms and other organisms that make up the soil food web are greatly reduced or nonexistent due to restricted air and water movement in the soil.
|Soils are living ecosystems that provide the needed air and water flow to support plant growth and a healthy soil food web. Rainfall is absorbed and replenishes groundwater supplies.||Determine soil type|
|Soils are exposed to sunlight, rain and wind||Soils are protected by vegetation or mulch.||Test your soil|
|Soils require frequent amending to support healthy vegetation.||Plants are selected that can thrive in the existing soil.||Support the soil food web|
|Organic matter such as leaves or grass clippings are removed from the soil and disposed of off-site.||Organic matter from the landscape is used to support the soil food web and healthy vegetation.||Apply organic mulch|
Why is soil health important?
Soil is critical to the success of sustainable gardens, and it provides important environmental benefits. Using sustainable gardening practices can help us restore the benefits our soils provide. Modern industrial society has left much of the Earth’s soil eroded, exhausted and polluted. Many unsustainable gardening practices, like applying too much fertilizer or compacting soil, have unwittingly contributed to the problem. The good news is it’s not too late! The health of our soils can be restored, and even enhanced, through the implementation of sustainable gardening techniques.
Soil is a valuable resource–nature can take more than 500 years to form just one inch of topsoil.
Soil is the foundation of a sustainable garden. It provides a variety of benefits, often without our knowing, including:
- Absorbing rainfall and mitigates flooding
- Removing pollutants and cleanses water
- Storing water for plants, wildlife and people
- Providing habitat for organisms such as microscopic bacteria and earthworms that transform wastes into nutrients for plants.
- Storing atmospheric carbon
- Sustaining plants, which provides food, fiber for clothing, timber, medicines and other goods