Comparing the yields of organic and conventional agriculture

Godfray, H. C. et al. Food security: the challenge of feeding 9 billion people. Science 327, 812–818 (2010)

Foley, J. et al. Solutions for a cultivated planet. Nature 478, 337–342 (2011)

McIntyre, B. D., Herren, H. R., Wakhungu, J. & Watson, R. T. International Assessment of Agricultural Knowledge, Science and Technology for Development: Global Report http://www.agassessment.org/ (Island, 2009)

De Schutter, O. Report Submitted by the Special Rapporteur on the Right to Food http://www2.ohchr.org/ english/issues/food/docs/A-HRC-16–49.pdf (United Nations, 2010)

Trewavas, A. Urban myths of organic farming. Nature 410, 409–410 (2001)

Badgley, C. et al. Organic agriculture and the global food supply. Renew. Agr. Food Syst. 22, 86–108 (2007)

Cassman, K. G. Editorial response by Kenneth Cassman: can organic agriculture feed the world-science to the rescue? Renew. Agr. Food Syst. 22, 83–84 (2007)

Connor, D. J. Organic agriculture cannot feed the world. Field Crops Res. 106, 187–190 (2008)

Berry, P. et al. Is the productivity of organic farms restricted by the supply of available nitrogen? Soil Use Manage. 18, 248–255 (2002)

Pang, X. & Letey, J. Organic farming: challenge of timing nitrogen availability to crop nitrogen requirements. Soil Sci. Soc. Am. J. 64, 247–253 (2000)

Crews, T. E. & Peoples, M. B. Can the synchrony of nitrogen supply and crop demand be improved in legume and fertilizer-based agroecosystems? A review. Nutr. Cycl. Agroecosyst. 72, 101–120 (2005)

Oehl, F. et al. Phosphorus budget and phosphorus availability in soils under organic and conventional farming. Nutr. Cycl. Agroecosyst. 62, 25–35 (2002)

Martini, E., Buyer, J. S., Bryant, D. C., Hartz, T. K. & Denison, R. F. Yield increases during the organic transition: improving soil quality or increasing experience? Field Crops Res. 86, 255–266 (2004)

Letter, D., Seidel, R. & Liebhardt, W. The performance of organic and conventional cropping systems in an extreme climate year. Am. J. Altern. Agric. 18, 146–154 (2003)

Colla, G. et al. Soil physical properties and tomato yield and quality in alternative cropping systems. Agron. J. 92, 924–932 (2000)

Scialabba, N. & Hattam, C. Organic Agriculture, Environment and Food Security (Food and Agriculture Organization, 2002)

Research Institute of Organic Agriculture (FiBL). Farming System Comparison in the Tropics http://www.systems-comparison.fibl.org/ (2011)

Crowder, D. W., Northfield, T. D., Strand, M. R. & Snyder, W. E. Organic agriculture promotes evenness and natural pest control. Nature 466, 109–112 (2010)

Bengtsson, J., Ahnström, J. & Weibull, A.-C. The effects of organic agriculture on biodiversity and abundance: a meta-analysis. J. Appl. Ecol. 42, 261–269 (2005)

Kirchmann, H. & Bergström, L. Do organic farming practices reduce nitrate leaching? Commun. Soil Sci. Plan. 32, 997–1028 (2001)

Leifeld, J. & Fuhrer, J. Organic farming and soil carbon sequestration: what do we really know about the benefits? Ambio 39, 585–599 (2010)

Valkila, J. Fair trade organic coffee production in Nicaragua—sustainable development or a poverty trap? Ecol. Econ. 68, 3018–3025 (2009)

Raynolds, L. T. The globalization of organic agro-food networks. World Dev. 32, 725–743 (2004)

National Research Council. Toward Sustainable Agricultural Systems in the 21st Century (National Academies, 2010)

Hedges, L. V., Gurevitch, J. & Curtis, P. S. The meta-analysis of response ratios in experimental ecology. Ecology 80, 1150–1156 (1999)

Rosenberg, M. S., Gurevitch, J. & Adams, D. C. MetaWin: Statistical Software for Meta-analysis: Version 2 (Sinauer, 2000)

Johnston, M., Foley, J. A., Holloway, T., Kucharik, C. & Monfreda, C. Resetting global expectations from agricultural biofuels. Environ. Res. Lett. 4, 014004 (2009)

Whittaker, R. J. Meta-analyses and mega-mistakes: calling time on meta-analysis of the species richness–productivity relationship. Ecology 91, 2522–2533 (2010)

Hillebrand, H. & Cardinale, B. J. A critique for meta-analyses and the productivity–diversity relationship. Ecology 91, 2545–2549 (2010)

Englund, G., Sarnelle, O. & Cooper, S. D. The importance of data-selection criteria: meta-analyses of stream predation experiments. Ecology 80, 1132–1141 (1999)

Ramankutty, N., Foley, J. A., Norman, J. & McSweeney, K. The global distribution of cultivable lands: current patterns and sensitivity to possible climate change. Glob. Ecol. Biogeogr. 11, 377–392 (2002)

Deryng, D., Sacks, W., Barford, C. & Ramankutty, N. Simulating the effects of climate and agricultural management practices on global crop yield. Glob. Biogeochem. Cycles 25, GB2006 (2011)

IGBP-DIS. Soildata (V 0): A Program for Creating Global Soil-Property Databases (IGBP Global Soils Data Task, 1998)

Monfreda, C., Ramankutty, N. & Foley, J. A. Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Glob. Biogeochem. Cycles 22, GB1022 (2008)

Food and Agriculture Organization of the United Nations (FAO). FAOSTAT http://faostat.fao.org (2011)

Gurevitch, J. & Hedges, L. V. Statistical issues in ecological meta-analyses. Ecology 80, 1142–1149 (1999)

Hedges, L. V. & Olkin, I. Statistical Methods for Meta-Analysis. (Academic, 1985)

Gurevitch, J., Morrow, L. L., Wallace, A. & Walsh, J. S. A meta-analysis of competition in field experiments. Am. Nat. 140, 539–572 (1992)

Liebhardt, W. et al. Crop production during conversion from conventional to low-input methods. Agron. J. 81, 150–159 (1989)

Drinkwater, L., Janke, R. & Rossoni-Longnecker, L. Effects of tillage intensity on nitrogen dynamics and productivity in legume-based grain systems. Plant Soil 227, 99–113 (2000)