I think there is an immense opportunity for open-source here. So many techies are yearning to get back in touch with nature, and contribute to the planet. Using your spare time and expertise to develop robofarmer software helps from both angles. Not only software - the hardware could be open sourced too! Seems like the perfect opportunity for 3D printed components and small machines.

The next Red Hat could come along and get paid to implement and support it all.