Perrennial Grain Crops

The Land Institute is working on a project called the Perennial Agriculture Project, which studies perennial crops (grains) for farmers and agriculture. 

It's exciting stuff because perennial plants don't have to be replanted each year.  The fields aren't torn up every single year, so that the farmer only has to care for the plants and harvest the crop.  This represents a significant reduction in fuel costs.  Also perennials have more extensive root systems and are capable of pulling nutrients from deeper in the soil.  Those deep root systems also increase drought tolerance and general crop stability.

Growing perennials is generally cheaper, which usually means that it has a lower energy cost.  Energy cost is a major factor when considering the environmental impact of some activity vs. the returned benefit.