pWe are not going back to the pleistocene age of the hunter-gatherers. Instead experts indicate that the worldrsquo;s population will increase from approximately six billion to nine billion by 2050--all to be fed, clothed and even fueled by agricultural products. Whatrsquo;s more, as people rise out of poverty, higher living standards such as greater meat consumption and personal mobility will place even more demand on food crop production (wheat, rice), animal feed (corn, soybeans), fiber (wood, cotton) and fuels (sugarcane, switchgrass). How can agriculturersquo;s output expand so dramatically without significantly increasing its environmental footprint, especially reckless deforestation to clear land for farming? Like contemplating office space in Manhattan, we must find a way to grow vertically, by increasing crop yields./ppAgriculture is not natural; it is a human invention. It is also the basis of modern civilization. Yet agriculture is not uniform in its practices or productivity: some 40 percent of the worldrsquo;s corn farmers still use nonhybrid, open-pollinated varieties that the U.S. abandoned decades ago, and their yields are far, far lower than what could be achieved with modern seed varieties. Nor is agriculture static. Yield increases through improved genetics are accelerating in crops that receive intense private research funding, such as corn, but are languishing in cassava and other important staples for the developing world, which get little or no support. Agriculture has significant ecological consequences, too: displaced forests and grasslands, greenhouse gas emissions from fertilizers and diesel-fueled farm machinery, and algae blooms from excess nutrient runoff. Clearly, there is much to improve on./p a href=http://www.scientificamerican.com/article.cfm?id=agricultures-sustainable-future[More]/a