Organic agriculture and food security: A decade of unreason finally implodes

Persistent claims over the past decade that transformation of world agriculture to organic methods could feed the world have been grossly overoptimistic because they have used faulty methodology. Estimation of organic productivity based on yield ratios (typically 0.75) of pairs of comparable crops grown organically or with nitrogen fertilizer fails to acknowledge the land that must be allocated to legumes for biological nitrogen fixation (BNF) by legumes to supply nitrogen for the growth of non-legume crops, either in situ or in imported manure. The consequent smaller area of land available for cereal crops further, and more significantly, reduces the overall productivity of organic compared to conventional agriculture. A recent paper that applied published yield ratios to demonstrate adequate productivity of world agriculture transformed to organic methods failed in its objective by demonstrating that the error in calculation proposed an organic system with at least three times more circulating nitrogen than the land allocated to legumes could possibly provide. Future estimates of organic productivity should return to the basics of BNF that have, in the past, established that around half of current world population could be fed organically.