A study published in the journal Environmental Microbiology says that organic farms have healthier soil—allowing for the plant roots to absorb soil nutrients and for the plant to fight disease—than farms that regularly use synthetic fertilizers.
In their studies, the researchers particularly looked for arbuscular mycorrhizal fungi, or AMF, in the soil samples they examined. AMF is what allows the plant’s roots greater absorption of soil nutrients as well as the plant’s ability to ward off disease. What they found was that organic farms had a much higher concentration and diversity of AMF compared to non-organic farms.
One of the researchers for this study, Dr. Christopher van der Gast, says, "For most people it is about what you can see above ground. But the below ground biodiversity of the organisms are also key. It is a missing factor that most people do not think about. Our research demonstrates that the way humans manage the landscape can play a key role in determining the distribution of microbial communities at both the local and regional scales."
Dr. van der Gast adds that pesticides, herbicides, and regular tilling of the soil all damage AMF and also reduce the ecological diversity of the farm soil. Additionally, nitrogen fertilizers—which are typically used in our agriculture—can accelerate mineralization of the soil’s organic reserves, resulting in loss of humus and a soil fertility reduction.
Fellow researcher Gary Bending of the University of Warwick says, “This work provides us with new understanding which we can use to promote these fungi in agricultural systems. This in turn could improve crop production. With the proportion of the earth's surface which is managed by humans increasing rapidly, this understanding is essential if we are to predict and manage microbial functioning in the environment to meet many of the major challenges faced by human society, such as food supply and the mitigation of climate change. Addressing these challenges, while maintaining environmentally sustainable agricultural practices, requires an understanding of microbial diversity.”
In a similar vein, the results of a $25.8 million, 4-year study indicate what may stand to reason—that organic farm soils containing higher biodiversity can create foods with higher nutritional value. For example, this study suggested that some organic foods—such as fruits, vegetables and milk—are more nutritious than non-organically produced food.
Professor Carlo Leifert of the Tesco Center for Organic Agriculture based at Newcastle University, said that research results suggest that eating organic food is equivalent to eating an extra portion of fruits and vegetables each day. A few examples that Leifert gives is that organic fruits and vegetables have up to 40% more antioxidants than non-organically grown produce, while organic milk contains up to 60% more antioxidants and healthy fatty acids than conventional milk.
Better soil, better food? Some studies sure are pointing that way.