The microscopic majority – we ignore them at our peril!

Producing sufficient crops while ensuring our farming practices are sustainable is the big challenge for agriculture. But as well as studying and improving crop plants we also have to understand the microbial diversity beneath the surface that allows those plants to grow and flourish.

Farming Futures posted a blog about soil diversity earlier this week. Well, here at the Centre for Ecology and Hydrology we’ve just finished some research into one aspect of soil diversity – microbial fungi.

We found that farming practices have a significant impact on the diversity of beneficial microbial fungi known to play important roles in crop productivity, soil recovery and maintenance of healthy ecosystems.  The conclusions of our recently published study could have important implications for the way we manage the agricultural landscape and tackle future food security issues.

We know that arbuscular mycorrhizal fungi (AMF) within soil form mutually beneficial relationships with plants. And for individual plants, increasing AMF diversity can promote growth and resistance to plant pathogens.  In the study, we investigated the distribution of AMF at nine arable and horticultural farms in England, with soil collected from both organically and conventionally managed fields at each farm. 

The results of our study indicate that farm management has a significant impact on AMF diversity. Organic farming was shown to promote higher diversity relative to conventional farming. AMF community composition reflected strains adapted to both local soil conditions and the specific management practice imposed.  Our findings suggest that conventional management practices dampened local differences in community composition, resulting in a more limited collection of common species.

The purpose of this study was not to imply that one form of farming practice is better than another. Certainly that would be the easiest and most simplistic route to take for any journalist or editor under pressure to meet a deadline. Indeed, our study was turned into an ‘organic versus conventional’ issue by one newspaper in particular.

But for us, this work deepens our understanding of these fungi in agricultural systems and therefore has potential to help improve crop production.  This understanding is essential if we are to predict and manage microbial functioning to meet many of the major challenges we face: particularly food supply and the mitigation of climate change.

Microbes may lack the charisma that we might associate with say red squirrels, pandas, or even ladybirds. But, despite being invisible to the naked eye, microbes and their communities are central to agriculture, health , waste treatment, and play key roles in many of the Earth’s elemental cycles. Given the importance of this microscopic majority, we ignore them at our own peril.

Christopher van der Gast is an environmental microbiologist at the Centre for Ecology & Hydrology.

• The study was led by Dr Christopher van der Gast at the Centre for Ecology & Hydrology and Dr Gary Bending from the University of Warwick.
• Further details about the study can be found here.