John Deere is purchasing Blue River Technology, a Californian startup that makes machine learning tools for agriculture. The acquisition (via Quartz) is worth $305 million, and is part of the tractor company’s multi-decade quest to automate farming. In the case of Blue River, what it’s buying is cutting-edge machine vision tools that help famers scan fields, assess crops, and get rid of weeds — all at the same time.

Blue River’s key technology is called “see and spray.” It’s a set of cameras that fix onto crop sprayers and use deep learning to identify plants. If it sees a weed, it’ll hit it with pesticide; if it sees a crop, it’ll drop some fertilizer. All these parameters can be customized by the farmer, and Blue River claims it can save “up to 90 percent” of the volume of chemicals being sprayed, while also reducing labor costs. You can watch a rather over-the-top video demo of the technology below:

The purchase of Blue River Technologies is a sign of increased interest in agriculture automation, but it’s also a good example of just how complicated — and difficult to automate — the farming industry is.

John Deere has been working on autonomous tractors before the likes of Google and Tesla even existed, but even its most advanced vehicles today only assist navigation. They still need a human in the cab. That’s because farming (like many other professions targeted by automation) is a job that’s full of all sorts of variables and unexpected tasks that only humans can deal with. You can automate some aspects of it, but you can’t just build a robot farmer, plug it in, and go home for the day.

Blue River Technology is one of the companies that’s bridging the gap between traditional agriculture and the fully automated farm of future, a future that may never come to pass. It’s not trying to replace farmers’ jobs, but aims to let them do more with less. Its technology makes for more efficient crop spraying in the same way that new fertilizers did decades ago. The difference today is that the innovation is digital, not chemical.