Evidence about yields using organic practices or synthetic inputs
s1. “Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable). Under certain conditions— that is, with good management practices, particular crop types and growing conditions—organic systems can thus nearly match conventional yields, whereas under others it at present cannot. To establish organic agriculture as an important tool in sustainable food production, the factors limiting organic yields need to be more fully understood, alongside assessments of the many social, environmental and economic benefits of organic farming systems." p.1. .... "The average organic-to-conventional yield ratio from our meta-analysis is 0.75 (with a 95% confidence interval of 0.71 to 0.79); that is, overall organic yields are 25% lower than conventional (fig. 1a)." Source: Verena Seufert, et al., Nature, “Comparing the yields of organic and conventional agriculture.” 2. For an overview reporting similar yields with chemical and organic farming: DAVID PIMENTEL, et al., Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems, BioScience, July 2005 / Vol. 55 No. 7 573 pg(s) 573–582.
Source: 1). Verena Seufert, Navin Ramankutty, and Jonathan A. Foley,“Comparing the yields of organic and conventional agriculture.” Nature, May 2012, Vol. 485, 229. http://www.nature.com/nature/journal/v485/n7397/full/nature11069.html 2). David Pimentel, Paul Hepperly, James Hanson, David Douds, and Rita Seidel, "Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems," BioScience, July 2005 / Vol. 55 No. 7 573 pg(s) 573–582. http://www.ce.cmu.edu/~gdrg/readings/2007/02/20/Pimental_EnvironmentalEn... [verified 4/25/14]