ONTARIO GRAIN FARMER AGRONOMY 31 Always read and follow label instructions. Member of CropLife Canada. FMC, the FMC logo and Authority are trademarks of FMC Corporation or an affiliate. ©2026 FMC Corporation. All rights reserved. 23347 - 12/25 WEED PREVENTION FROM THE GROUND UP In the battle against tough weeds, soybean growers can let their soil do the fighting. Authority® Supreme herbicide, applied pre-plant or pre-emergence, creates a powerful soil-based defence that weeds can’t get past. The effective Group 14 and Group 15 combination delivers broadleaf and grassy weed control that keeps soybeans clean through the critical weed-free period. 23347 Authority brands print ad_ONTARIO GRAIN FARMER_HalfPage.indd 1 2025-12-23 4:09 PM a low-but-harvestable biomass in two of the three years. Berseem and Balansa clover may not establish well when planted after winter wheat harvest in August, especially if conditions are dry. Peas were more reliable but were still not a high biomass producer when planted by themselves. “In the end, although each farm and field is different from the next and growing season conditions are also going to vary from year to year, harvesting one of these cover crop mixtures that displays greater yield stability for forage purposes appears to be a reliable option for helping cover the upfront cost of cover crops,” Schneider says. But she adds a note of caution. Cutting the aboveground biomass of cover crops for forage may make cover cropping more profitable in the short term, it’s possible that this may reduce some of the benefits of cover crops in the long term. This needs further exploration in a longer-term study.” SOIL HEALTH BENEFITS More recommendations about the use of cover crops to improve corn performance come from a long-term study conducted by Laura Van Eerd and her colleagues in plots at the university’s Ridgetown Campus. A few different annual cover crops were planted by the team from 2007 to 2020 (but only 10 of those 13 seasons because of the pandemic). In 2020, the team planted grain corn and again in 2021. In 2021, there was a 60 bushel per acre increase in dry grain corn yield with radish compared to the no cover crop control or oat cover crop. “This was the first time that we saw a positive grain yield response to cover cropping,” Van Eerd says. In previous years, they saw no difference or slight but insignificant grain crop yield boosts with cover crops. In the 30 trials since 2007, they planted cover crops 169 times and found that 167 times (almost 99 per cent), the main crop yield was only as good as or a little better with a cover crop than without. However, 2021 was different, Van Eerd says, because conditions existed that may have boosted the yield benefits of cover crops. “The season was dry early on, so in a year where rain is scarce for the first part of the growing season, it seems that the enhanced soil health with long-term cover cropping contributed to corn grain yield gains,” she says. “The mechanism appears to be related to improved N cycling with available water.” In another part of the investigation, Van Eerd and her team looked at soil health in plots that were planted with annual cover crops six times over eight years. They found – as have many other researchers – that soil health was significantly better in plots with cover crops compared to no cover crops. This research was funded in part by the Ontario Agri-Food Innovation Alliance, a collaboration between the Government of Ontario and the University of Guelph. •
RkJQdWJsaXNoZXIy MTQzODE4