I understand that, despite the popularity of organic foods, clothing and other products, organic agriculture is still only practiced on a tiny percentage of land worldwide. What’s getting in the way?
— Larry McFarlane, Boston, MA

Organic production may still represent only a small fraction of agricultural sales in the U.S. and worldwide, but it as been growing rapidly over the last two decades. According to the latest global census of farming practices, the area of land certified as organic makes up less than one percent of global agricultural land—but it has grown more than threefold since 1999, with upwards of 37 million hectares of land worldwide now under organic cultivation. The Organic Trade Association forecasts steady growth of nine percent or more annually for organic agriculture in the foreseeable future.

But despite this growth, no one expects organic agriculture to top conventional techniques any time soon. The biggest …