Smart farming is about how emerging and evolving technologies support the farmer, and their professional network, in the management of production and of information related to production. Decision support is therefore a core concern. As decision support is actually about making the right decisions and undertaking the right action, it relates to precise functions. From these functions, three themes can be identified, which are developed in this chapter. The first theme concerns building information that can support decisions from spatial data. This includes defining the decision to be supported, including spatial scaling matters, identifying the knowledge management paradigm, the timeliness of decision and action and the criteria involved. The second theme is about optimization and planning. It includes concepts and methods that can be related to decisions taken during the nonproduction periods, such as strategical enterprise objectives and choices of tactics, as well as to decisions taken during the production cycle, which can be simple scheduling of operations or more complex choices aimed at adapting crop management to the specific characteristics of a given year. The third theme is about designing an information system for smart farming. This includes considering the production processes and making models of these and the general framework for design. It also includes elements related to implementation of proposed next-generation databases.