b'COVER CROP CORNERWHAT WEEDS ARE REALLY TELLING US:UNCOVERING THE SECRETS OF SOIL SUCCESSIONSINCE THE DAWN OFagriculture, the battle againstsupply is in place at seeding. Throw fungicide weeds has raged. Defiant plants growing whereapplications into the mix, and you will reduce they are not wanted. Weed presence seemed tofungal growth, widening the fungal:bacterial accelerate with monocultures, tillage, and theratios. These issues stop our soils from moving up use of fertilizer. To add insult to injury, nowin succession, allowing higher successional plants weed control is complicated by having herbicideto receive signals to grow. By staying in the early tolerant weeds, and weeds that are not easilysuccessional stages, early successional plants are By Kevin Elmy killed by tillage. Maybe these rogue plants aretriggered to grow. Hence, you get weeds.Elmy is founder of Covertrying to tell us something. Maybe there is aNot all weeds are triggered by low successional Crops Canada. His booksreason for these weeds. stages. Perennial weeds such as thistle and Not Just Dirt and CoverIn Dr. Elaine Inghams presentations, she talksdandelion indicate that there is an anaerobic Cropping in Westernabout plant succession, which is a series of similarzone in the soil, relating to poor soil structure Canada are availableplants that grow in a particular soil state. Sheand a low calcium supply rate in the soil. These through Friesen Press, Amazon, and digitallyhas identified a range of ratios of fungal:bacterialweeds are calcium and phosphate accumulators, through Apple Books,populations in the soil. In early successional soils,plus they are mycorrhizal fungi-friendly. The Kindle, and Google Play.bacteria are the dominant type of microbes indeep tap roots are bringing up more calcium to For more info on Coverthe soil, which will quickly cycle nutrients andrelease back into the soil. This will flocculate the Crops Canada visitsupport fast-growing plants. This in turn willsoil minerals, creating more aeration. The root covercrops.ca start to develop soil.exudates of the weeds will support more microbial As the soil organic matter rises, a highergrowth, especially in the compacted areas, helping fungal:bacterial ratio will be supported,to speed up the soil remediation process.allowing higher successional plants to grow.Without changing management, the weeds This process will continue, starting with simplewill persist. To effectively get the weeds to soils supporting early plant forms, to grasslands,disappear, we need to support the function of forbs and flowers, shrubs and vines, andthe weeds, ideally without relying solely on eventually trees. Environmental and agriculturalthe weeds. It may mean doing some surgical management will allow the succession to movetillage, creating minimal disturbance to get the either forward or backwards. desired results, then helping the system repair by Annual weeds are typically early successionaladding cover crops which do similar jobs as the plants, present when the fungal:bacterial ratio isweeds. relatively low. With a high bacterial population,There is something in our management system nitrogen tends to get broken down quickly.that is not allowing our soils to successionally Lower successional plants use nitrate as a mainmove forward, away from the conditions that source of nitrogen. Nitrate requires a significanttrigger weed growth. Once we provide conditions amount of energy to transform to amino acids orwhere the plants can thrive, we can eliminate other forms as compared to ammonium, urea, orweed, disease and insect issues. It is said that more complex nitrogen containing molecules likedisease and insects are the garbagemen of nature; amino acids. As the fungal component of the soilthey take out garbage plants.increases, the amount of nitrate tends to decrease,Utilizing cover crops to help move the being replaced by ammonium. successional path does not have to be complicated. By utilizing modern agronomic practices, weWe must be aware of the implications of modern tend to move the fungal:bacterial ratio lower.chemical-based agronomic practices and what Tillage damages fungal hyphae and stimulatesthey do to the soil microbes, plant exudates, and bacterial growth. Synthetic fertilizer stimulatesnutrient cycling. Any damage done to the system bacterial growth and typically drives up availableneeds to be repaired and strengthened. Cover nitrates in the soil, especially when the entirecrops can play a major role in this. 36 SEEDWORLD.COM/CANADA NOVEMBER 2024'