Efficiency gains up to 40 percent
Cropland faces challenges from numerous plant pathogens that can curb growth and yield. A Swiss research effort shows that introducing mycorrhizal fungi into soil can help crops maintain or even boost production without relying on chemical fertilizers or pesticides. In a large field trial, yields rose by as much as 40 percent in some plots.
Fertilizer and pesticide overuse reduces biodiversity and harms the environment. As a result, there is strong interest in sustainable methods to protect crops without agricultural chemicals. Mycorrhizal fungi are beneficial organisms that assist plants in accessing nutrients and water from the soil, offering a biological alternative to conventional inputs.
Field validation on a large scale
Researchers from the Universities of Zurich and Basel, along with Agroscope and FiBL, demonstrated practical effectiveness of soil inoculation with mycorrhizal fungi across a wide area. The fungi were introduced into soil before planting on 800 test plots across 54 maize farms in northern and eastern Switzerland, marking a substantial real world test. The study confirms that inoculation can improve yields under typical farming conditions, not just in controlled experiments.
One quarter of the plots experienced up to 40 percent higher yields. This outcome surprised researchers and highlighted the potential of the approach. However, about one third of the land did not show yield gains, and in some cases productivity did not increase initially. The reasons behind these variations remain to be fully understood.
To uncover contributing factors, the team examined soil chemistry, physical properties, and the broader soil microbiome. They found that inoculation tends to be most effective when soil already hosts a higher level of fungal pathogens. In other words, the protective shield created by the fungi helps plants cope with pathogen pressure and often stabilizes yields in fields facing disease risk. In soils with few pathogens, the fungi provided only limited benefits.
In cases where plants are already strong and healthy, the additional use of mycorrhizal fungi did not yield noticeable extra benefits, according to another study author. This finding helps explain why some fields see clear gains while others do not.
Predicting where it will work best
The study aimed to determine the conditions under which inoculation with mycorrhizal fungi is most effective. By using a small set of soil indicators, particularly related to fungal communities, researchers could predict success in about nine of ten fields before the growing season began. This predictive capability suggests future use can be targeted to areas with the greatest potential for benefit.
Experts emphasize that such predictability is essential for turning this biological approach into a reliable agricultural practice. Further work is needed to identify the most efficient methods for distributing the fungi across large landscapes. Still, the field results are viewed as a significant step toward more sustainable farming practices that rely less on chemical inputs.
Reference work: DOI 10.1038/s41564-023-01520-w
Additional notes: the study underscores the potential of leveraging soil biology to support crop yields while reducing chemical dependence. This aligns with broader goals of sustainable agriculture and soil health management. [Citation attributions provided within the study data]