Watch more CNET News: http://bit.ly/1LGPOmk Farmers have been able to drive tractors hands-free for years. Now, there's even more technology to help with planting and harvesting. CNET's Shara Tibken visited John Deere's test farm in Iowa. Subscribe to CNET: http://bit.ly/17qqqCs Watch more CNET videos: http://www.cnet.com/video Follow CNET on Twitter: http://twitter.com/CNET Follow CNET on Facebook: http://www.facebook.com/cnet