Excessive use of fertilizers and pesticides in agriculture reduces biodiversity and pollutes the environment. Hence, there may be great interest find sustainable ways to guard yields without the usage of agrochemicals. An example of different organisms is mycorrhizal fungi, that are useful organisms that help plants obtain nutrients.
Productivity improved by 40%
A team of researchers from the Universities of Zurich and Basel, AgroScope and the Research Institute of Organic Agriculture (FiBL) have now shown for the primary time on a big scale that using mycorrhizal fungi in the sector works. The fungus was mixed into the soil before sowing the crops on 800 test plots on 54 maize farms in northern and eastern Switzerland. “On a quarter of the plots, mycorrhizal fungi improved yields by up to 40 percent. That's huge,” says Marcel van der Heijden, a soil ecologist on the University of Zurich and Osgroskop. But there's a catch: on a 3rd of the plots, yields didn't increase and in some cases even decreased. The investigation team was initially unable to clarify why this happened.
Pathogens in soil
To discover why, the researchers analyzed quite a lot of chemical, physical and biological characteristics, including the biodiversity of soil microbes. “We discovered that inoculation works best when there are already many fungal pathogens in the soil,” says co-first writer Stephanie Lutz of AgroScope, a federal agricultural research center. “Mycorrhizal fungi act as a kind of protective shield against pathogens in the soil that weaken plants.” As a result, normal yields could be maintained in fields where mycorrhizal fungi would have had no losses. In contrast, mycorrhizal fungi had only a minor effect on fields not contaminated with pathogens. “The plants there are strong and grow best anyway. In such cases the use of mycorrhizal fungi does not bring any additional benefit,” says second first writer Natacha Bodenhausen from the Research Institute of Organic Agriculture.
Vaccination success could be assessed.
The study, funded by the Gebert Roof Foundation, aimed to evaluate the conditions under which mycorrhizal inoculation works. “With just a few soil indicators — especially soil fungi — we were able to predict inoculation success in nine out of 10 fields, and thus crop yield before the field season. could even predict,” say study participants. Led by Klaus Schlapp of the University of Basel. “This prediction makes it possible to target the use of fungi in the fields where they will work. This is a key factor in developing these technologies into reliable agricultural practices,” says Schläppi.
More research is required to search out the best approach to spread the fungus over large areas. Nevertheless, “the results of this field trial represent a major step towards more sustainable agriculture,” concluded Marcel van der Heijden.