Biodiversity continues to decline rapidly, despite decades of repeated national and international policy efforts. Agricultural intensification is a major driver of biodiversity losses, while conversion to organic farming has been suggested as a key technique to halt or reverse this trend.
In this article, led by Teja Tscharntke that just came out in Trends in Ecology and Evolution (TREE), we argue that in contrast to this widespread view, certified organic agriculture raises local richness of widespread species by just a third when compared to conventional farming. This is achieved through waiving synthetic agrochemicals, but leads to considerable yield losses, requiring the conversion of more land to agriculture to obtain similar yields.
Diversifying cropland and reducing field size on a landscape level can multiply biodiversity in both organic and conventional agriculture without reducing cropland productivity. Complementing such increases in cropland heterogeneity with at least 20% seminatural habitat per landscape should be a key recommendation in current biodiversity frameworks.
The original publication is available here: https://www.sciencedirect.com/science/article/abs/pii/S016953472100183X