Whether you’re using existing soil, or importing soil to fill raised garden beds, soil amendments are a vital resource for the garden. Many neglected urban soils are compacted and low in organic matter. Soil amendments are designed to add organic material back into soil, reduce compaction, and improve soil life. Here are some tips from the Soil Science Society of America.
1. Compost is organic material that has decomposed into a stable state that’s then available for adding to soil. Anything that was once alive can be composted; therefore different composts can vary in their properties. Some of the most common composts available to urban residents are made from the yard debris that is collected curbside from residents. You can also make your own compost.
2. Manure can give your garden an incredible boost in nutrients. Make sure the manure you use has been well aged or composted. Check with local agriculture organizations to see if they have a list of local farms willing to share their manure or buy this from your local garden center.
3. Biosolids are the digested, solid portion extracted from the wastewater treatment process. They may not sound pretty—but there’s nothing better for creating an amazing garden. In addition to being 100% recycled and full of macro- and micro-nutrients, biosolids work to build healthy soil like nothing else. Biosolids are also held to stringent standards by the EPA and have been repeatedly shown to be a safe, effective way to build healthy soil.
You can add amendments to soil anytime, but the best times for working them into an existing garden are in the spring before planting, and in the fall when putting the garden to bed. Generally, two to three inches is sufficient to work into the soil gently with a shovel.
For information, visit soils.org/discover-soils/soils-in-the-city or the blog called Soils Matter at soilsmatter.wordpress.com/