A comprehensive review of the science reveals that organic farming benefits all types of above-ground biodiversity

Photo Credit: Markus Spiske

Biodiversity is critical for the function of ecosystems both on and off the farm. In recent years, we’ve seen dramatic losses of biodiversity for various reasons including changes in climate, land use, and increasing chemical use in farming. Organic farming practices by design are intended to support and even increase biodiversity, yet the outcomes of these practices have been controversial. A new study published in the journal Organic Agriculture combined data from 98 studies and found that organic farming does indeed increase the diversity and abundance of plants, insects and birds, providing an effective strategy to combat biodiversity loss. The study used 474 comparisons of species richness and abundance in conventional versus organic farms. Overall species diversity or abundance, including all plants, insect and animals, was higher in organic farms for 58% of those comparisons. Plants showed the most benefit from organic farming, with 95% of abundance comparisons higher in organic arable (farmed) land, and 21% higher in field margins. Insect abundance and diversity were also higher for organic in 36% and 22% of comparisons respectively. Finally, the abundance and diversity of birds were higher in 24% and 35% respectively in organic farms. The authors highlighted that while they were able to use many studies for comparison, the method used for measurements highly varied. Future research could benefit from doing whole farm measurements, rather than only sampling one crop or one field. This is especially important for crop diverse farms and farms with a lot of non-crop vegetation beneficial to biodiversity and characteristic of many organic farms