The Future: six drivers of global change Part 81

355 expensive liability instead of a valued a.s.set

Ibid., p. 78.

356 nontoxic manure as fertilizer and a three-year crop rotation

Mark Bittman, "A Simple Fix for Farming," New York Times, October 19, 2012.

357 virtually all of the nitrogen is derived

U.S. Government Accountability Office, "Domestic Nitrogen Fertilizer Depends On Natural Gas Availability and Prices," 2003, p. 1, http://www.gao.gov/products/GAO-03-1148.

358 use per acre has been increasing dramatically

Jeremy Grantham, "Time to Wake Up: Days of Abundant Resources and Falling Prices Are Over Forever," GMO Quarterly Letter, April 2011.

359 devoid of life, which are growing in several ocean regions

Robert Diaz and Rutger Rosenberg, "Spreading Dead Zones and Consequences for Marine Ecosystems," Science, April 15, 2008.

360 recent spectacular algae blooms in Chinese

"No Easy Fix," Economist.

361 U.S., China, Southeast Asia, and parts of Latin America

"Nitrogen Pollution an Increasing Problem Globally," PRI's The World, January 27, 2009, http://www.pri.org/stories/science/environment/nitrogen-pollution-an-increasing-problem-globally-8166.html.

362 tripled the depletion of phosphorus from cropland

David Vaccari, "Phosphorus: A Looming Crisis," Scientific American, June 2009.

363 where 65 percent of U.S. production now takes place

Ibid.; James Elser and Stuart White, "Peak Phosphorus," Foreign Policy, April 20, 2010.

364 search for new reserves is beginning again

Ibid.

365 the "Saudi Arabia of phosphorus"

Ibid.

366 exports during the 2008 food price crisis

Elser and White, "Peak Phosphorus."

367 order to extend the supplies of phosphorus for fertilizers

Mara Grunbaum, "Gee Whiz: Human Urine Is Shown to Be an Effective Agricultural Fertilizer," Scientific American, July 23, 2010.

368 soil fertility and enhance the sequestration of soil carbon

Rifat Hayat et al., "Soil Beneficial Bacteria and Their Role in Plant Growth Promotion: A Review," Annals of Microbiology 60, no. 4 (December 2010): 57998; Tim J. LaSalle, Regenerative Organic Farming: A Solution to Global Warming, Rodale Inst.i.tute, July 30, 2008, pp. 23, http://www.rodaleinst.i.tute.org/files/Rodale_Research_Paper_07_30_08.pdf.

369 soil and further protect against erosion

J. Paul Mueller, Denise Finney, and Paul Hepperly, "The Field System," in The Sciences and Art of Adaptive Management: Innovating for Sustainable Agriculture and Natural Resource Management, edited by Keith M. Moore (Ankeny, IA: Soil and Water Conservation Society, 2009).

370 fertility of the soil while diminis.h.i.+ng erosion

Huggins and Reganold, "No-Till: The Quiet Revolution."

371 carefully managed way can also improve yields and soil quality