Organic yields lag conventional by 20% in developed countries, 43% in Africa, meta-analyses find

In most regions of the world, row-crop farming is primarily conducted in [large] fields, but knowledge of processes and management recommendations are typically based on research in [small] experimental plots. This scale mismatch has long raised questions about inferences that are made from plot-scale experiments to entire fields or farms

Experimental-scale–related yield gaps for organic grain crops can be especially substantial. Recent meta-analyses of plot-scale studies suggest organic yield penalties of 20–25% on average, although possibly as low as 8%. Farmer surveys, on the other hand, report organic grain yield penalties of 27–34%.

• The corn yield under conventional management was almost twice that in the organic management when precipitation levels exceeded 500 mm.
• Conventional management was more resilient to field-scale challenges than alternative practices, which were more dependent on timely management interventions; in particular, mechanical weed control.
• Corn yields in the field-scale experiment Bio [organic] treatment were >45% lower than in Conv [conventional] management, and wheat Bio yields were >30% lower than in Conv management
• [S]oybean [organic] yield reductions were 55%, 27%, and 88% in 2010, 2011, and 2012, respectively.