Synthetic fertilizers have dramatically increased food production worldwide. But the unintended costs to the environment and human health have been substantial. Nitrogen runoff from farms has contaminated surface and groundwater and helped create massive "dead zones" in coastal areas, such as the Gulf of Mexico. And ammonia from fertilized cropland has become a major source of air pollution, while emissions of nitrous oxide form a potent greenhouse gas.

These and other negative environmental impacts have led some researchers and policymakers to call for reductions in the use of synthetic fertilizers. But in a report published in the June 19 issue of the journal Science, an international team of ecologists and agricultural experts warns against a "one-size-fits-all" approach to managing global food production.

"Most agricultural systems follow a trajectory from too little in the way of added nutrients to too much, and both extremes have substantial human and environmental costs," said lead author Peter Vitousek, a professor of biology at Stanford University and senior fellow at Stanford's Woods Institute for the Environment.

"Some parts of the world, including much of China, use far too much fertilizer," Vitousek said. "But in sub-Saharan Africa, where 250 million people remain chronically malnourished, nitrogen, phosphorus and other nutrient inputs are inadequate to maintain soil fertility."

Other co-authors of the Science report include Woods Institute Senior Fellows Pamela Matson, dean of Stanford's School of Earth Sciences, and Rosamond L. Naylor, director of the Program on Food Security and the Environment.

China and Kenya

In the report, Vitousek and colleagues compared fertilizer use in three corn-growing regions of the world--north China, western Kenya and the upper Midwestern United States.

In China, where fertilizer manufacturing is government subsidized, the average grain yield per acre grew 98 percent between 1977 and 2005, while nitrogen fertilizer use increased a dramatic 271 percent, according to government statistics. "Nutrient additions to many fields [in China] far exceed those in the United States and northern Europe--and much of the excess fertilizer is lost to the environment, degrading both air and water quality," the authors wrote.

Co-author F.S. Zhang of China Agriculture University and colleagues recently conducted a study in two intensive agricultural regions of north China in which fertilizer use is excessive. Their results showed that farmers in north China use about 525 pounds of nitrogen fertilizer per acre (588 kilograms per hectare) annually--releasing about 200 pounds of excess nitrogen per acre (227 kilograms per hectare) into the environment. Zhang and his co-workers also demonstrated that nitrogen fertilizer use could be cut in half without loss of yield or grain quality, in the process reducing nitrogen losses by more than 50 percent.

At the other extreme are the poorer countries of sub-Saharan Africa, such as Kenya and Malawi. In a 2004 study in west Kenya, co-author Pedro Sanchez and colleagues found that farmers used only about 6 pounds of nitrogen fertilizer per acre (7 kilograms per hectare)--little more than 1 percent of the total used by Chinese farmers. And unlike China, cultivated soil in Kenya suffered an annual net loss of 46 pounds of nitrogen per acre (52 kilograms per hectare) removed from the field by harvests.

"Africa is a totally different situation than China," said Sanchez, director of tropical agriculture at the Earth Institute at Columbia University. "Unlike most regions of the world, crop yields have not increased substantially in sub-Saharan Africa. Nitrogen inputs are inadequate to maintain soil fertility and to feed people. So it's not a matter of nutrient pollution but nutrient depletion."

U.S. and Europe

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A comparison of 3 agricultural areas of the world found massive imbalances in fertilizer use, resulting in malnourishment in some regions and pollution in others. Photo: David Nance, USDA

The contrast between Kenya and China is dramatic and will require vastly different solutions, the authors said. However, large-scale change is possible, they said, noting that since the 1980s, increasingly stringent national and European Union regulations and policies have reduced nitrogen surpluses substantially in northern Europe.

In the Midwestern United States, over-fertilization was the norm from the 1970s until the mid-1990s. During that period, tons of excess nitrogen and phosphorus entered the Mississippi River Basin and drained into the Gulf of Mexico, where the large influx of nutrients has triggered huge algal blooms. The decaying algae use up vast quantities of dissolved oxygen, producing a seasonal low-oxygen dead zone in the Gulf that in some years is bigger than the state of Connecticut.

Since 1995, the imbalance of nutrients--particularly phosphorus--has decreased in the Midwestern United States, in part because better farming techniques have increased yields. Statistics show that from 2003 to 2005, annual corn yields in parts of the Midwestern United States and north China were almost the same, even though Chinese farmers used six times more nitrogen fertilizer than their American counterparts and generated nearly 23 times the amount of excess nitrogen.

"U.S. farmers are managing fertilizer more efficiently now," said co-author Rosamond Naylor, who is also a professor of environmental Earth system science and senior fellow at Stanford's Freeman Spogli Institute for International Studies. "The dead zone in the Gulf of Mexico persists due to continued fertilizer runoff and animal waste from increased livestock production."

Low nitrogen in Africa

In sub-Saharan Africa, the initial challenge is to increase productivity and improve soil fertility, the authors said. To meet that challenge, co-author Sanchez recommends that impoverished farmers be given subsidies to purchase fertilizer and good-quality seeds. "In 2005, Malawi was facing a serious food shortage," he recalled. "Then the government began subsidizing fertilizer and corn seeds. In just four years production tripled, and Malawi actually became an exporter of corn."

Food production is paramount, added co-author G. Philip Robertson, a professor of crop and soil sciences at Michigan State University. "Avoiding the misery of hunger is and should be a global human priority," Robertson said. "But we should also find ways to do this without sacrificing other key aspects of human welfare, among them a clean environment. It doesn't have to be an either/or choice."

For countries where over-fertilization is a problem, the authors cited a number of techniques to reduce environmental damage. "Some of these--such as better-targeted timing and placement of nutrient inputs, modifications to livestock diets and the preservation or restoration of riparian vegetation strips--can be implemented now," they wrote.

Designing sustainable solutions also will require a lot more scientific data, they added. "Our lack of effective policies can be attributed, in part, to a lack of good on-farm data about what's happening with nutrient input and loss over time," said co-author Alan Townsend, an associate professor of ecology and evolutionary biology at the University of Colorado-Boulder. "Both China and the European Union have supported agricultural research that yields policy-relevant information on nutrient balances. But the U.S. is particularly lacking in long-term data for a country with such a well-developed scientific enterprise."

Even in Europe, with its strong research programs on nutrient balances and stringent policies for reducing fertilizer runoff, nitrogen pollution remains substantial. "The problem of mitigation of excess nitrogen loss to waters is not easily resolved," said co-author Penny Johnes, director of the Aquatic Environments Research Centre at the University of Reading, U.K. "Society may have to face some difficult decisions about modifying food production practices if real and ecologically significant reductions in nitrogen loss to waters are to be achieved."

According to Vitousek, it is important in the long run to avoid following the same path to excess in sub-Saharan Africa that occurred in the United States, Europe and China. "The past can't be altered, but the future can be and should be," he said. "Agricultural systems are not fated to move from deficit to excess. More effort will be required to develop intensive systems that maintain their yields, while minimizing their environmental footprints."

Other co-authors of the Science report are Tim Crews, Prescott College; Mark David, University of Illinois at Urbana-Champaign; Laurie Drinkwater, Cornell University; Elisabeth Holland, National Center for Atmospheric Research; John Katzenberger, Aspen Global Change Institute; Luiz Martinelli, University of São Paulo, Brazil; Generose Nziguheba, Columbia University; Dennis Ojima, The H. John Heinz III Center for Science, Economics and the Environment; and Cheryl Palm, Columbia University.

This work is based on discussions at the Aspen Global Change Institute supported by NASA, the William and Flora Hewlett Foundation, and the David and Lucile Packard Foundation; and at a meeting of the International Nitrogen Initiative sponsored by the Scientific Committee on Problems of the Environment.

Professor Walter P. Falcon, Deputy Director of the Center on Food Security and the Environment (FSE), former director of FSI, and Helen Farnsworth Professor of International Agricultural Policy, Emeritus has been recognized with an honorary degree from McGill University for his research aimed at reducing world hunger and enhancing global food security.

Professor Falcon's expertise is in food policy, commodity markets, trade policies, and regional development. Professor Falcon's current research focuses on agricultural decision-making in Indonesia and Mexico, biotechnology, climate change, and biofuels.

From 1972 to 1991, Professor Falcon served as professor of economics and director of Stanford University's Food Research Institute, after which he directed the Freeman Spogli Institute for International Studies until 1998. From 1998 to 2007 he co-directed the Center for Environmental Science and Policy. At Stanford he has also served as senior associate dean for the social sciences, a member of the academic senate, and twice a member of the University's Advisory Board.

Professor Falcon has also consulted with numerous international organizations, been a trustee of Winrock International, and was chairman of the board of the International Rice Research Institute (IRRI). From 1978 to 1980, he was a member of the Presidential Commission on World Hunger and in 1990 was named a Fellow of the American Agricultural Economics Association. From 1996-2001 he served as chairman of the board of the International Corn and Wheat Institute (CIMMYT), and from 2001-07 served on the board of the Center for International Forestry Research (CIFOR).

Falcon was cited as the outstanding 1958 graduate of Iowa State University in 1989 and in 1992 was awarded the prestigious Bintang Jasa Utama medal of merit by the government of Indonesia for twenty-five years of assistance to that country's development effort.

[See video interview with Chris Field and David Lobell here].

Biofuels such as ethanol offer an alternative to petroleum for powering our cars, but growing energy crops to produce them can compete with food crops for farmland, and clearing forests to expand farmland will aggravate the climate change problem. How can we maximize our "miles per acre" from biomass?

Researchers writing in the May 7, 2009, edition of the journal Science say the best bet is to convert the biomass to electricity rather than ethanol. They calculate that, compared to ethanol used for internal combustion engines, bioelectricity used for battery-powered vehicles would deliver an average of 80 percent more miles of transportation per acre of crops, while also providing double the greenhouse gas offsets to mitigate climate change.
 
"It's a relatively obvious question once you ask it, but nobody had really asked it before," said study co-author Christopher B. Field, director of the Department of Global Ecology at the Carnegie Institution. "The kinds of motivations that have driven people to think about developing ethanol as a vehicle fuel have been somewhat different from those that have been motivating people to think about battery electric vehicles, but the overlap is in the area of maximizing efficiency and minimizing adverse impacts on climate."
 
Field, who is also a professor of biology at Stanford University and a senior fellow at Stanford's Woods Institute for the Environment, is part of a research team that includes lead author Elliott Campbell of the University of California-Merced and David Lobell of Stanford's Program on Food Security and the Environment.

America's standing in the world has been damaged by eight years of unilateralism and it must cooperate with rising powers to tackle emerging transnational threats, according to a major research project to be unveiled Thursday, Nov. 13, at a conference hosted by Stanford's Freeman Spogli Institute for International Studies (FSI).

The directors of "Managing Global Insecurity Project (MGI)" (MGI) from Stanford's Center for International Security and Cooperation (CISAC), New York University and the Brookings Institution will use the conference to present their "plan for action" for the next U.S. president.

"President-elect Obama should take advantage of the current financial crisis and the goodwill engendered by his election to reestablish American leadership, and use it to rebuild international order," said CISAC's Stephen J. Stedman. "Part of that is to recalibrate international institutions to reflect today's distribution of power. If you could find a way for constructive engagement between the G-7 and Russia, China, India, Brazil and South Africa-that reflects the reality of world power today-you could actually animate a lot of cooperation."

Stedman, Bruce Jones from New York University's Center on International Cooperation and Carlos Pascual from Brookings will discuss concrete actions for the incoming administration to restore American credibility, galvanize action against transnational threats ranging from global warming to nuclear proliferation and rejuvenate international institutions such as the United Nations.

"You find in American foreign policy a blanket dismissal of international institutions, especially regarding security," Stedman said. "But if you eliminate them, you don't have a prayer of recreating the kind of cooperation that exists in the U.N. There actually is a pretty good basis of cooperation on which to build."

The nonpartisan project also will be presented Nov. 20 at a high-profile event at the Brookings Institution that will feature leaders such as former Secretary of State Madeleine Albright and Brookings President Strobe Talbott. That in turn will take place on the heels of the upcoming G-20 emergency summit to discuss measures to stave off a global recession and give a greater voice to developing nations. MGI's "plan for action" includes a series of policy papers on hot-button topics such as economic security.

"The big thing we talk about is if you institutionalize cooperation with the existing and rising powers you can hope to build a common understanding of shared long-term interests," Jones said. "If you approach issues only through the lens of the hottest crises, you will find different interests in the very short term on how [problems] are handled."

Transitions 2009

The 20-month-long project, which incorporated feedback and direction from nonpartisan U.S. and international advisory boards, dovetails closely with the theme of FSI's fourth annual conference: "Transitions 2009."

"There has rarely been a moment more fraught with danger and opportunity, as new administrations in the United States and abroad face the interlocking challenges of terrorism, nuclear proliferation, climate change, hunger, soaring food prices, pandemic disease, energy security, an assertive Russia and the grave implications of failed and failing states," FSI Director Coit D. Blacker said. "This conference will examine what we need to do to prepare our own citizens for the formidable challenges we face and America's own evolving role in the world."

Timothy Garton Ash, an Oxford professor and Hoover Institution senior fellow, will deliver the conference's keynote address, titled, "Beyond the West? New Administrations in the United States and Europe Face the Challenge of a Multi-Polar World."

Blacker, who served in the first Clinton administration; Stephen D. Krasner, who worked in the current Bush administration; medical Professor Alan M. Garber; and Stanford President Emeritus Gerhard Casper will open the conference with a reflection on the past and future and the watershed moment presented by Obama's presidency. The conference also will include breakout sessions with FSI faculty such as "Rethinking the War on Terror," led by Martha Crenshaw of CISAC; "Toward Regional Security in Northeast Asia," chaired by former Ambassador Michael J. Armacost, acting director of the Shorenstein Asia-Pacific Research Center; and "Is African Society in Transition?" led by economist Roz Naylor of the Program on Food Security and the Environment.

Long-term security

For MGI project leaders Stedman, Jones and Pascual, the zeitgeist of the moment is America's relationship with the emerging powers. "The good news from an American perspective is, despite the financial crisis, despite everything else, sober leadership in China, India, Brazil and elsewhere understand, in the immediate term, there is no alternative to American leadership, as long as [it] is geared toward cooperation and not 'do as you please-ism,'" Jones said. "On the other side, the financial crisis highlights that U.S. foreign policy has to come to terms with the fact that it does not have the power to dictate outcomes. It has to build cooperation with emerging powers, with international institutions, into the front burner of American foreign policy." More broadly, international cooperation must be built on what Stedman calls the principle of "responsible sovereignty," the notion that sovereignty entails obligations and duties toward other states as well as to one's own citizens.

In addition to MGI's "plan for action," the three men have coauthored Power and Responsibility: International Order in an Era of Transnational Threats, to be published in 2009. The book criticizes both the Bush and Clinton administrations for failing to take advantage of the moment of U.S. dominance after the fall of the Soviet Union to build enduring cooperative structures. "We're in a much tougher position than we were five years ago and 10 years ago," Jones said. "There still is an opportunity, but time is getting away from us."

If revitalizing international cooperation fails, Jones said, transnational threats will gain the upper hand. "We will not be able to come to terms with climate change, transnational terrorism, spreading nuclear proliferation," he said. "U.S. national security and global security will deteriorate. [We] have a moment of opportunity to do this now."