Uncovering the Secrets of Healthy Soils: A Nordic Agriculture Revolution
Soil health is the cornerstone of sustainable agriculture, and Norway is leading the way with groundbreaking research on cover crops. But here’s where it gets controversial: the exact benefits and mechanisms of cover crops, especially in Nordic climates, have been a mystery—until now.
A recent study, led by Dr. Thiago Inagaki from the Norwegian Institute of Bioeconomy Research (NIBIO), has revealed that root growth is a key driver in forming stable organic matter in soil, known as mineral-associated organic matter (MAOM). This discovery was published in the journal Agriculture, Ecosystems & Environment, shedding light on a critical aspect of soil health.
“This form of carbon is incredibly resilient, persisting in the soil for years, which is a powerful tool in the fight against climate change,” Dr. Inagaki explains. “Our study shows that cover crop systems, particularly those with ryegrass and clover, significantly enhance MAOM storage.”
The research was conducted at Tuv Gård in Steinkjer, Norway, where cover crop systems have been managed for five years. The team investigated the effects of different cover crop mixtures on soil quality, nutrient cycling, carbon storage, and crop yields.
One of the study’s key findings is that encouraging root growth is the most effective way to build long-lasting soil organic matter in Norway. “While more diverse mixtures, like those with chicory and bird’s-foot trefoil, improved soil structure and microbial abundance, these benefits didn’t immediately translate into higher carbon storage. It seems some advantages take time to emerge,” Dr. Inagaki notes.
“Instead of solely focusing on total carbon, we should prioritize the formation of stable organic matter fractions through biologically intensive practices,” he adds.
An upcoming study by Dr. Frederik Bøe, also from NIBIO, further supports these findings. It shows positive interactions between root growth and microbial abundance in promoting nutrient cycling, particularly phosphorus. This indicates that root growth not only enhances carbon storage but also nutrient retention.
The study led by Dr. Thiago also addressed a common concern among farmers: yield penalty. His research found that adding cover crops, even in diverse mixtures, doesn’t reduce barley yields. “Cover crops can improve soil health without compromising productivity,” he says, “addressing farmers’ fears of nutrient competition.”
The multidisciplinary team also explored the use of biochar, a carbon-rich soil amendment. While it didn’t significantly boost soil quality or yields in this study, it also caused no harm. “The effects of biochar may be limited to specific circumstances, like degraded or polluted soils,” Dr. Thiago suggests. “But with no negative impacts observed, it remains a promising practice for carbon storage and could become economically viable for farmers as carbon credits develop.”
The story continues as NIBIO’s team delves deeper into the nitrogen cycle and plant development in Steinkjer as part of the AgroMixNorth project. Meike S. Bärmann, a master’s student from Goethe University, is evaluating plant development and soil fertility throughout the cropping season, guided by Dr. Inagaki.
“This next phase will uncover how cover crops and root systems optimize nutrient cycling and soil health in Nordic agriculture, with a special focus on nitrogen dynamics,” Dr. Inagaki says. “Our goal is to reframe soil management practices in Nordic agriculture based on these findings.”
For more information, refer to the study by Thiago M. Inagaki et al., published in Agriculture, Ecosystems & Environment (2026). DOI: 10.1016/j.agee.2025.109968.