b'COVER CROP CORNERFALL COVER CROPPING ENSURES LONG-TERM NUTRIENT RELEASE INTO SOILONE OF THEcornerstones of regenerative agricul- crops receive by utilizing the microbes from the ture is to have plants growing in the soil for asrhizosheaths of past species grown. many days of the year as possible. While todaysAnother benefit of fall cover crops is the sup-agronomic practices are predominately based onpression of weeds. Nature does not like mono-using annual cash crops, it is an opportunity tocultures but hates bare soil. Post-harvest, the soil get cover cropping into the management fold.biology is still living, so nutrients are still cycling. Doing so will help solve some of the reoccur- Without plants taking up the nutrients, weeds are ring problems producers face like compaction,triggered to grow to ensure the nutrients will not By Kevin Elmy erosion, nutrient availability and weeds. be lost from the system. Having a fall cover crop Elmy is founder of CoverFall seeding cover crops can be quite chal- will allow the microbes to continue to thrive by Crops Canada. His bookslenging. Lack of growing days after harvest, soilbeing fed exudates from the cover crop; the cover Not Just Dirt and Cover Cropping in Westernmoisture availability, labour and time to seed allcrop is encouraged to grow by the nutrient avail-Canada are availableplay against the desire to get started. The crops weability. through Friesen Press,grow are chosen to mature in our growing area,Due to the plants being quite young, the Amazon, and digitallymaximizing the number of days the crop cancarbon-nitrogen ratio will be relatively low, so through Apple Books,grow, leaving a small window post-harvest. Butthey will rot early in the spring, releasing those Kindle, and Google Play. For more info on Coverthere are ways around these issues.nutrients back into the soil. If there are still an Crops Canada visitWhy do we want to have plants growingabundance of weeds growing with the cover crop, covercrops.ca in the fall post-harvest? Will it use up the soillook at changing the species used, seeding the moisture creating a drought next year? Will it tiecover crop earlier or increase the seeding rate of up nutrients from the next crop? Will there bethe cover crop. enough moisture in the fall to get the cover cropThe importance of having plants growing in established? All legitimate questions and con- the fall is crucial in developing stable soil aggre-cerns.gates. Without a living plant injecting liquid But weeds grow in the fall. Cover croppingcarbon into the soil as a root exudate, most of the allows us to determine what plants are growingsoil microbes have low activity levels. and understanding the function of weeds, we canWhen we have a fall cover crop pushing root prevent triggering weeds to grow and speed upexudates into the soil, the soil microbes will use the soil-building process. some of the liquid carbon from the root exudate Soil moisture is a typical concern, and grow- and winterize the soil aggregates. This will allow ing plants requires water. In the fall, if there isthe aggregate to withstand the freeze-thaw cycles.enough moisture to grow weeds, small-seededWith each season of continued stable aggregate cover crops can be grown. For spring moisture,building, we then can see aggregation deeper into overwintering species can dry the soil out if notthe soil profile. managed but can help wet spring conditions.Fall cover cropping is one of the necessary Nutrients get tied up if plant material has notsteps to start accelerating soil health. Having the rotted down. We can influence this by managingliving root allows the soil biology to continue the plant stage at freeze-up. More mature plantsfunctioning without having to scavenge the soil in have more structure tissues like lignin which takeits search for carbon sources. By strengthening the a longer time to break down and release nutrients,soil aggregates, the soil microbes will be able to whereas vegetative plants will rot down quicker,handle stress better, increase water storage in the releasing nutrients more quickly the next year.soil and make the soil more resilient to stresses. Key is having a mixture of green plant mate- Of course, fall cover cropping is not just about rial and mature plant material, and low and highseeding in the fall. A relay cover crop seeded carbon-nitrogen plant materials.in the spring can reduce the risk of fall seeding Increasing functional plant families to youroptions. We just need to get vegetative plants rotation leads to increasing the legacy effect togrowing in the fall, maximizing the days we have future crops. The legacy effect is the benefit futurea living root in the soil. SEPTEMBER 2024 SEEDWORLD.COM/CANADA 35'