THE DIRT ON SOIL, PART 1
(HEY, READ THIS- IT’S IMPORTANT!)
As in all older cities in the U.S., soils in our beloved Somerville can contain contaminants. On a site that has always been residential, the most common contaminant found is lead. (Part 2 of this post will address lead in soil.) When a site has had other uses, such as industrial or agricultural, it contain many other contaminants. Be sure to research the site history before you plant your garden. You can overcome the obstacles encountered in urban farming to become more informed and garden safely.
1. As a best practice, it is recommended that urban produce be grown in containers or raised beds built from wood that does not contain old paint on it and has not been chemically treated, or from another safe material. First turn the existing soil, to help with drainage. Then, place landscape fabric, available at hardware stores, on the turned earth and build the raised bed on it.This provides a barrier to the old soil, while allowing water to infiltrate. If you have problems with critters, you can also put a wire hardware cloth below all of it to prevent any burrowing. There are many ways to build a raised bed and many tutorials out there. Search the web to find guides and videos and do what works best for you. You can find more tips in the “Agriculture ” section of ABC’s of Urban Ag, a guide to urban ag in Somerville.
2. Next, fill the raised bed with clean, TESTED soil. Be sure you know where your soil comes from. Do not buy untested soil from someone’s city yard, from the internet or from an urban site, as it is likely to be contaminated. If you buy soil from a nursery or landscaper, ask where it comes from and if it has been tested for contaminants. Place gardens away from structures with flaking paint and be aware that clean soils can become contaminated by activities like the scraping or weathering of leaded paint on a nearby structure.
3. Finally ,plant and grow delicious, local food! Remember, in Somerville, under the new Urban Agriculture Ordinance, if you plan to sell your produce, a soil test is required and must be posted. See Pg 11 of the ABC’s of Urban Ag.
Stay tuned, part two will discuss lead, the most common contaminant found in urban soils.