Agricultural intensification: will land spared from farming be land spared for nature?

How can intensive agricultural systems be designed so that they have fewer and smaller impacts on surrounding ecosystems? This is not a new challenge, but its importance to conservation—particularly in developing regions—has become apparent in recent years. This challenge is a major part of the ongoing effort to provide for the needs of a growing human population and at the same time sustain the life-support systems of the planet (Vitousek et al. 1997; National Resource Council 1999). To many in the conservation community, a growing human population makes the goal of harmonizing food production and conservation all but impossible. That psychological landscape has changed fundamentally, however— the end of human population growth is within sight over most of Earth (the peak population will be realized sooner and at a lower level with intensified, committed effort). Nevertheless, population will continue to grow for some decades. In many areas, standards of living and levels of nutrition will (and should) increase. What are the best ways to meet the dual challenges of agricultural production and conservation? Many agronomists suggest that the best way to meet those challenges is through intensifying agriculture and increasing yields on the “best” lands. That way, the necessary production can be obtained on the smallest area of land and more land can be “saved for nature” (Waggoner 1995). Intensification leading to increased yields per hectare provided most of the last doubling of agricultural production—and the potential for another doubling in yields now attracts both debate and research. An alternative pathway by which agricultural production and conservation could be harmonized is wildlife-friendly farming, which involves designing agricultural systems so that they support important components of biological diversity within the agricultural landscape itself. Recent analyses by Green et al. (2005) and Balmford et al. (2005) evaluated these alternatives regionally and