b'COVER CROP CORNERARE COVER CROPS AN ANSWER TOMITIGATING CLIMATE CHANGE?THERE IS A lot of talk about climate change. Many people point to agriculture as one of the potential sources to the answer of mitigating it. Carbon dioxide is usually talked about as the bad greenhouse gas. Agriculture has an excellent answer to help balance atmospheric carbon dioxide.Photosynthesis is the process of combin-Kevin Elmy ing carbon dioxide and water in a plants Elmy is founder of Coverchlorophyll to produce sugar and oxygen. Crops Canada. His bookWhen a plant is in the vegetative stage, it will Cover Cropping in Westernrelease up to 80 per cent of the sugar and Canada is availableother carbon-based compounds into the soil through Friesen Press,to feed soil biology. Over a plants life, it will Amazon, and digitallyrelease between 30 per cent and 50 per cent through Apple Books,of the total carbon pulled out of the air asCanola being used as a nurse crop for perennial ryegrass. Kindle, and Google Play.root exudates. By including a cover crop as either a relay cover crop or a For more info on CoverIn the past, organic matter was thought topost-harvest cover crop, we allow usable root exudates to Crops Canada visitbe built from above-ground plant residues.be released for more days of the year.covercrops.ca Research has shown that up to 80 per cent of the carbon in the above-ground parts of the plant are lost to the atmosphere. How stableincrease of carbon in the soil, the soil will be organic matter is made is through root exu- able to hold more moisture. Water actually dates and a healthy functioning soil microbialcontributes more as a greenhouse gas than population. what carbon dioxide does. Plus, having more One of the ways to capture carbon diox- moisture in our soils will help plants produce ide and store it is through plants, especiallyunder times of reduced rainfall. That is the plants in the vegetative stage. Cash croppingend goal of decreasing atmospheric carbon annual species has most plants in the vegeta- dioxide.tive stage for 30-40 days. This is where coverUsing cover crops will help get more crops have potential for agricultural produc- carbon into the soil, assuming goals are set ers to crank up their carbon sequestration.and appropriate species are utilized. Species By including a cover crop as either a relayused as cover crops should have delayed cover crop or a post-harvest cover crop, wematurity, be low growing so as not to inter-allow usable root exudates to be releasedfere with harvest, should support mycorrhizal for more days of the year by feeding morefungi and tie up excess nutrients (but at the soil microbes, building organic matter, andsame time be able to release them as the crop sequestering carbon by having a vegetativerequires them, and to continue to feed the plant growing. soil biology root exudates).By increasing the amount of carbon heldBy making this one addition to our current in our soil, the soil health rises. Increases inmanagement, we can make a difference in health come from feeding the soil microbiol- both the soil health and also help to mitigate ogy, stronger soil aggregation, quicker waterclimate change. Getting carbon into the soil is infiltration, improved drought tolerance anda win for everyone. Keeping a vegetative plant a lot more. Meanwhile, the carbon dioxidegrowing for as many days as possible is one is removed from the atmosphere. With theof the keystones of soil health principles. 32GERMINATION.CASEPTEMBER 2021'