To reach beyond its traditional businesses, Emerson CEO Chuck Knight appointed a "growth czar," Charlie Peters, who helped each business develop initiatives, mostly outside their traditional customer base. Peters tracked the initiatives in a central "war room." In addition to opportunities within each business unit, the existence of a growth czar helped business units gather engineering and marketing expertise from throughout the company to create new business models that cut across existing divisional boundaries. Combining resources across divisional boundaries often plays a key role in cultivating the larger world as a Fertile Field.

NiSource, the $3.1 billion-a-year parent of Northern Indiana Public Service Co., is another Fertile Field innovator. It began innovating in the 1980s because it had to, developing unregulated power plants for industry because the steel mills and chemical refineries it served would have gone to someone else for the services if it had not done so. Under president Gary Neale the company has expanded that business to make it the leading developer of on-site industrial power generation in the U.S. Beyond that, Neale has encouraged senior NiSource managers to explore where the assets and competencies of a good public utility could contribute more. At first, NiSource kept individual bets small. The few where NiSource went far afield didn't work out. (A used-tires-to-energy plant in Britain, for example, was closed.) But NiSource has created value with close-to-home investments. It is managing unregulated pipelines and natural gas storage facilities and has installed the first commercial microgenerator in the U.S., in a Walgreen's store in Chesterton, Ind. The generator uses the gas that NiSource supplies to generate electricity as well as heat on site, cutting costs while increasing reliability - and opening an enormous potential market for the company.

Fertile Field challenges differ radically from those of either Cauldron or Spiral Staircase. Where a Spiral Staircase manager must nurture passionate loyalty to customers and to the business, the key to managing Fertile Field innovation is to encourage exploration of new frontiers. That frequently means discouraging people from too much concern with existing customers and the existing business. Where Spiral Staircase innovation calls for experimentation throughout the organization to capture the upside in a business with growth potential, Fertile Field innovation demands training for people with traditional backgrounds so they can see opportunity in related fields and use their skills to seize it. Where Spiral Staircase innovation demands teams focused on improving the customer's experience, Fertile Field innovators gain more from task forces that look outside the organization. They rarely benefit training all the rank-and-file in innovation. (NiSource tried doing so, and reaped little benefit.)

Teams that work on Fertile Field innovations, then, are necessarily an elite. That doesn't mean they should consist exclusively of senior managers or a band of young M.B.As. A company's best customer service representatives or even its best truck drivers may understand the real nature of the company's assets and competencies - and what can be done with them - in a way that people on the fast track may not. But where everyone should feel they're part of the team working on Spiral Staircase innovations, smaller groups have to drive Fertile Field exploration.