Farmers around the world contend with a long list of challenges, including climate change, rapid urban growth, and soil degradation. In response, researchers are turning their attention to feasibility and practical solutions—especially sustainable farming practices like cover crops—to build resilient systems that work in diverse regions across Canada and the United States.
Protective measures and supplementary products can be integrated with the main crop to shield soil from wind, rain, and heat, particularly outside the main production cycle. These strategies help preserve soil structure and fertility even during periods of vulnerability.
Cover crops are planted soon after harvest and terminated before the next cash crop goes in. They form a living cover that protects soil health and reduces erosion during fallow periods.
Cover crop roots stabilize soil, improve structure, and aid in nutrient management by absorbing and storing excess nitrogen from fertilizers. Residues may remain in the soil after a commercial harvest, contributing to soil organic matter and moisture retention.
Beyond soil benefits, cover crops help prevent manure and sediment from reaching waterways, safeguarding freshwater ecosystems from pollution and sedimentation.
Common cover crop species include herbs such as wheat, rye, oats, and barley; brassicas like radish, turnip, canola, and mustard; and legumes such as peas, broad beans, and clover. This practice is widely valued in crop rotation, no-till farming, and organic farming for its role in building soil health and long-term productivity.
Key role in soil health
Cover crops influence soil organic carbon (SOC), which is central to soil health and the long-term sustainability of agricultural systems. Recent reports in the Journal of Agronomy highlight how conservation agriculture benefits from cover crops as a strategy to mitigate land degradation, climate pressures, and food insecurity in developing regions. The analysis also examines SOC and greenhouse gas emissions within maize systems, drawing on a synthesis of prior studies.
Findings indicate that cover crops can raise SOC levels, a marker of healthier soil capable of supporting resilient crops. They also impact soil microbes, moisture, and carbon cycling, contributing to more stable yields over time. This approach aligns with broader conservation agriculture technology aims to minimize land degradation and adapt farming to a warming climate.
One key takeaway is that the use of cover crops detains carbon dioxide from the atmosphere and stores it in the soil, offering a natural climate mitigation angle while enhancing soil health. This perspective underscores the climate and agronomic co-benefits of living soil covers. (attribution: Journal of Agronomy, 2024)
High carbon retention potential
Researchers found that maize fields employing cover crops show notable SOC retention. Estimates suggest that if all U.S. cornfields adopted cover crops, as much as 29.12 million Mg of SOC could be sequestered annually, equivalent to around 107 million metric tons of CO2. This magnitude mirrors the annual emissions of nearly 24 million gasoline-powered vehicles. (attribution: Environmental Science assessments, 2023)
According to the U.S. Environmental Protection Agency, these figures illustrate the potential scale of soil carbon gains and their climate relevance. In the study, researchers note that current cover crop adoptions in maize systems sequester about 5.5 million Mg of SOC annually in the United States, with global potential reaching hundreds of millions of Mg per year. The outcome is improved soil biology, moisture retention, and carbon storage, alongside potential increases in crop yields for subsequent seasons. The meta-analysis also reports maize yields rising by about 23% with cover crops. (attribution: National Agricultural Research Community, 2022)
In field observations, cover crops support soil microorganisms and moisture, while contributing to higher carbon levels. This triad benefits crop performance in the long run, aligning soil health with productivity goals across diverse farming systems.
Earlier studies, including international collaborations, indicate that extending vegetation periods in cereal crops can boost yield, biodiversity, climate regulation, and soil fertility. These insights emphasize the value of closing the time gap between harvest and the next crop using strategic cover crop placements. (attribution: CSIC studies, 2021)
The CSIC work, along with partners from Alicante and Rey Juan Carlos University, highlights the broader agronomic and environmental gains from cover crops, particularly in cereal production and soil ecosystem health. Further reading is suggested in the CSIC compilation of related findings. (attribution: CSIC study series, 2021)
Note: This summary reflects synthesized findings from multiple sources focused on cover crops, soil health, and climate considerations. (attribution: aggregated research review, 2021–2024)