Why Does The Safety Of Compost Matter?

1. Why Does The Safety Of Compost Matter? Compost can be made from food scraps, yard waste, animal waste, or from just about anything that was ever once living. How can we be sure that the compost we intend to use to grow healthy fruits and vegetables won’t end up harming our crops or even worse, us! Any glance in your local lawn and garden center will reveal new chemicals that promote their ability to grow this but will help to kill that. Too often, untested chemicals are allowed to come to market and then are abruptly regulated for limited use or banned altogether. There are several, well-documented cases of agriculture chemicals coming to market and causing havoc years after they were applied. What are the potential dangers of untested compost? Since compost can be made from anything that was once alive the potential dangers of an untested compost can vary widely. Salmonella, E-coli, lead, mercury, arsenic, and residual agricultural chemicals all pose a threat to humans if left unchecked via untested compost. A study of bagged and bulk composts produced in facilities in the western United States found that: “A large number of compost samples examined in this study possessed fecal bacteria levels that exceeded the EPA 503 rule.” Knowing the source of your compost, and obtaining any available documents or test results is the best way to ensure the safety of your soil amendments. Interpreting compost testing results. pH– This value (0-14) will tell you how acidic or alkaline the compost is. Knowing this value can greatly help determine if any changes need to be made before applying to plants that are known for loving certain acidic/alkaline conditions. Rhododendrons, blueberries, and azaleas are acid-loving plants and prefer a soil pH around 5.5. Conversely, vines like honeysuckle, clematis and Boston ivy are alkaline loving plants and thrive in soil with a pH around 7.5 Basic plant nutrients (NPK) – Nitrogen, Phosphorus and Potassium are the 3 basic nutrients all plants need to thrive. Depending on the species and seasonal needs of the plant, the ratio of these 3 nutrients needs to be adjusted. For compost, these values aren’t near as informative as the Organic Matter Content because NPK values tend to be very ephemeral (here today, gone tomorrow).

2. Organic Matter Content – (the more the better) The percentage of organic matter content is a much more stable value than NPK values when regarding total or potential nutrients. Organic matter contributes to total nutrients available in finished compost and increased moisture retention of soils once amended. Organic matter can provide habitat for various types of organisms and once the organic matter is decomposed, it becomes available as a wide array of nutrients and minerals for plants. Herbicide and Pesticide Residues – Chemical herbicides and pesticides have been known to persist and remain active well beyond the most rigorous composting processes. Once we thought it safe to measure this sort of contamination in ‘parts per million’. Unfortunately, as these chemicals come into markets in stronger and more concentrated formulas, ‘parts per billion’ is becoming more and more the standard of measurement. The absence of harmful pathogens – A healthy compost operation will kill off most harmful pathogens like salmonella and E-coli. Any time animal manure is added to compost or soil, the risk of exposure to a harmful pathogen increases dramatically. An optimal compost will be totally free of or have a minimal presence of harmful pathogens. All bulk compost should have been tested at some point and should come with ‘paper’. Some bulk compost delivery operations could be several steps down the chain from the source of the compost and may not have access to these documents. These tests can cost several thousands of dollars to perform. Small farms or at home compost operations may not be able to afford or may not be required to perform some or any of these tests. So how can we keep ourselves safe from the dangers of compost from unknown origins? Testing Unknown Compost At Home I suggest two tests. “The Duck Test” and “The Grow Test”. No animals will be harmed in the process of these tests… The Duck Test 1.Look at your compost. It should be well broken down and dark, almost black. It also shouldn’t look like sludge. The largest particles should be ½ inch or less. 2. Feel your compost. Compost shouldn’t be too compacted. Break up any clumps to see inside them. Compost should be well decomposed and very little non- broken down material should remain. It should be moist enough that you could form a small ball or mass in your hand without excess liquid dripping out. On the opposite end of the spectrum, it should not be so dry that it can blow away in the wind. 3. Smell your compost. It should smell earthy, like a forest floor or soil. If you detect a bitter, rancid or offensive smell, trust your nose and avoid using this compost. Conclusion: If it looks like good compost, feels like good compost, and smells like good compost… Well, chances are that it IS good, healthy compost.

3. If your unknown compost passed The Duck Test, proceed onto The Grow Test. The Grow Test 1.Obtain 2 growing containers. These should hold at least 4 cups of soil each and should allow for draining of excess water. Fill both containers with your unknown compost. 2.In 1 container of compost plant beans or peas according to their proper spacing and depth listed on their package. Water thoroughly. In the other container of compost, plant nothing and water it thoroughly as well. The container with beans or peas planted will allow us to see if trace herbicides are present in the unknown compost. The container with nothing planted will allow us to see if there are viable weed seeds that survived the composting process. 3. Observe for two weeks. Conclusion: In the container with beans or peas, we should see healthy sprouts start to form within the time listed on the package and continued healthy growth for the duration of the test. In the other container with nothing planted, we should see no activity. If any mystery plants start to sprout, there could be noxious plant seeds just waiting to make a new home in your garden. Knowing anything about compost is always better than knowing nothing. Keeping your garden, crops, foods, and family safe is paramount. Thank you for taking the time to read my post. Feel free to post on social media to share with friends. Keep up to date with everything going on at Food Loops by following us on Facebook and Instagram. Source URL: https://foodloops.net/2019/01/03/why-does-the-safety-of-compost- matter/