Is it Zach\u2019s birthday? You might think so. Because on this episode of Field Work, Joe Liefer of John Deere joins Zach and Mitchell to talk about green tractors, a thing Zach loves. Liefer is an engineer at John Deere who has been working on the company\u2019s autonomous 8R tractor, which doesn\u2019t require a human behind the steering wheel. Instead, it has six pairs of stereo cameras so it doesn\u2019t bump into stuff like, you know, fence posts.