Back to top

Are Compost and Soil the Same Thing?

Have you ever found yourself wondering if compost and soil are the same thing?
While they are both beneficial, they are not quite the same. We'll tell you why! 

Compost is a small but important part of soil. Compost is made from your decomposed kitchen and yard waste and becomes the living part of soil. Soil is the top layer of earth and consists of varying proportions of minerals, organic matter, water, and air. The graphic below shows approximate amounts of each component since soils vary on the amount of clay, sand and silt in their mix.

Note, of course, that these percentages can change across regions, seasons, even throughout the day, and are especially dependent on how the soil is managed. The organic matter in compost is what adds nutrients and feeds the food soil web so it must be restored periodically. 

Here in San Diego County, depending on where you live, the mineral component of your soil can vary from clay to sandstone or granite. Except for native plantings, landscape and garden soil will benefit from the addition of nutrient-rich compost. Increasing the organic matter content of soils is vital to building healthy soil. By increasing organic matter content in your soil, you are likely to see better water permeability, greater ease in working the soil, and improved soil aeration.

If you'd like to learn more about composting and creating healthy soil join us for our upcoming Backyard Composting Webinar Thursday, June 11th & Saturday, June 13th. Register to hold your spot! 

Related: