At Coast of Maine we come across occasional articles in regard to tainted compost. We asked our co-owner and resident compost expert, Pete Bottomley, to give us his thoughts. Enjoy the read! Is your compost safe? To me, this is such a sad question.
The natural process of composting is a miracle of biological complexity where microscopic microbes, miniature crustaceans, insects and spiders work together to decompose vegetative or animal matter into stable and highly beneficial organic matter: Organic matter we can use to boost the productivity of our gardens. Compost is good. Compost is beyond reproach……. Except when human beings get involved! Leave it to us to sully compost’s reputation.
Composting organisms will do what they have to do to get the job done no matter the quality of the starting inputs. This is like our gastrointestinal microbes who are constantly deluged with the deadly man-made toxins toxins we eat on a daily basis….. They adapt and do their best without complaint. Just as the human body eventually degrades from the toxic load, there are contaminants in the feedstocks of some compost recipes which overwhelm the composting microbes.
Nature is diverse and tends to prefer entropy and a dispersed state. Humans, on the other hand, organize, standardize and concentrate materials. We concentrate metals, chemicals (including pesticides), hormones, food and waste. Human pollution is so ubiquitous that the soil in your backyard is contaminated with lead and mercury from decades of atmospheric deposition. Where did the pollution come from? It came from you and me!
The composting process reduces the materials which are used. Heat, carbon dioxide, water vapor and other gases are released. Some of the material converts into the living tissue of insects who move on to other places. In the end, if there was something man-made, and indigestible, in the compost, it will still be there. Compost containing grass clippings will harbor high concentrations of the pesticides people thoughtlessly put on their lawns. Compost from dairy cows has been found to contain herbicides used to control pasture weeds and persistent antibiotics. Compost from human sewage is chock full of heavy metals, pesticides and pharmaceuticals.
Depending on the intended use, a tainted compost may be fine. If you are growing vegetables for consumption, however, then you really want to know if your compost producer knows what is in all the feedstocks that are used.
The bottom line: If you are looking for compost to grow plants for consumption, due diligence is important. If you want to use your local municipal compost, find out if they are using grass clippings, and, if they are, are they testing for pesticides.
Compost is valuable and highly beneficial for increasing vegetable production and quality. There are excellent compost products available, and there are options that may be polluted. If you have questions, give us a call and we will help you.