Now Cropping Up: Robo-Farming

India's Mahindra & Mahindra, one of the biggest suppliers of smaller tractors to the U.S., and other manufacturers are racing to develop what they see as the future of farming: robo-tractors and other farming equipment to help produce more food, more sustainably at a lower cost. John Deere has tractors and combines on the market that free the driver in the cabin from the actual driving so he or she can monitor the crops and adjust pesticide, water and soil levels. Technology from Agco Corp.'s Fendt lets several driverless tractors follow a lead tractor driven by a human. Japanese firms Kubota and Yanmar are planning to launch driverless tractors that they expect to be popular with elderly farmers. The next generation is tractors that can drive entirely by themselves.