Study debunks myths on organic farms

I have a hard time taking this at face value. If organic farming is so much better than "conventional" farming, why did farmers ever start using these toxic chemicals and other non-organic processes? There must be a reason for this. I might imagine that switching to a chemical-based approach produced better yields initially, but production slowly decreased over time (such that people didn't notice) until dropped below the yields of the original "organic" farming methods. But this is just a theory, and I'd love to know the reality.

I read through their "full report" (http://www.rodaleinstitute.org/files/FSTbookletFINAL.pdf), which is barely more than a press release, and the only mention of how they conducted the study tells me it was a poorly controlled experiment:

"The crop rotations in the organic systems are more diverse than in the conventional systems, including up to seven crops in eight years (compared to two conventional crops in two years)."

Also, be sure to keep the source of this study in mind:

"Rodale Institute is a 501(c)(3) nonprofit dedicated to pioneering organic farming through research and outreach. For over sixty years, we’ve been researching the best practices of organic agriculture and sharing our findings with farmers and scientists throughout the world, advocating for policies that support farmers, and educating consumers about how going organic is the healthiest option for people and the planet."

For me, a poorly conducted experiment by a very biased source, who doesn't publish any details on said experiment, and which contradict most conventional wisdom should be met with great skepticism.

Excerpt:

"In fact, studies like the Rodale trials (www.rodaleinstitute.org/fst30years) show that after a three-year transition period, organic yields equalled conventional yields. What is more, the study showed organic crops were more resilient. Organic corn yields were 31 per cent higher than conventional in years of drought.

These drought yields are remarkable when compared to genetically modified (GM) "drought tolerant" varieties, which showed increases of only 6.7 per cent to 13.3 per cent over conventional (non-drought resistant) varieties."