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.

The year 2009 is a big one for China and the ruling Communist Party (CCP), as years ending in the number 9 mark several important anniversaries. In 1919, May 4 witnessed the patriotic, “modernizing” youth movement that catalyzed the formation of the CCP. In 1949 the People’s Republic of China (PRC) was established, and 1979 saw the inauguration of reform and opening, which re-legitimized the Party after the Cultural Revolution debacle and set China on the path to record-breaking economic growth and international power and status.

These are not the only “9” years, however, that mark milestones in recent Chinese history. 1959 saw Beijing crush the Tibetan uprising against PRC rule that led the Dalai Lama to flee into exile; it was also the first of three years of mass starvation in the Great Leap Forward. In 1979, the brief but bloody Sino-Vietnamese War took place. And in 1989 the leadership of the Chinese People’s Government ordered the People’s Liberation Army to fire on unarmed Chinese people demonstrating in Tiananmen Square.

Needless to say, some anniversaries are celebrated with great fanfare, as moments in the nation’s history of which all citizens can and should be proud. Massive parades to commemorate the sixtieth anniversary of the PRC’s founding can certainly be expected this October. In the run-up to anniversaries of events-that-should-be-forgotten, by contrast, dissidents are detained, the media muzzled, websites suddenly shut down for “maintenance,” and public security intensified at sensitive venues such as the Potala Palace in Lhasa and Tiananmen Square in Beijing. This month, angered by what it perceives as interference in its internal affairs, China has rebuked foreign dignitaries, including Taiwan’s President Ma Ying-jeou and U.S. Secretary of State Hillary Clinton, for their calls on the CCP leadership to acknowledge those killed at Tiananmen. According to Foreign Ministry spokesman Qin Gang, China has already reached a verdict on that history. The Party has set the country on “the proper socialist path that serves the fundamental interests of the Chinese people,” and there is nothing more to be said.

Enforcing historical forgetting, however, requires more than clampdowns at anniversary time and stony assertions that matters are resolved. Efforts to silence critical voices are ongoing, and the so-called Great Firewall of China routinely blocks access to sensitive information on the Internet. Meanwhile, despite liberalization—which has allowed professional historians considerable freedom to address many hitherto taboo topics—the content of museums, memorials, historical films and television dramas, and, above all, school textbooks remain restricted through a battery of laws, regulations, and vetting mechanisms. In line with official diktats, these officially authorized histories generally gloss over unhappy episodes or rewrite them to present a mostly happy tale of inexorable progress since 1949, and to portray the Party and the country in a positive light. If mentioned at all, acts of state violence or suppression are represented as necessary measures taken to safeguard national territory, unity, and stability. At the same time, in order to emphasize a common national bond against external threats, they highlight past acts of aggression that foreign countries committed against China. This patriotic history is not “my country, right or wrong;” rather, it is “my country (and the Party) has always been right.”

Despite these concerted efforts, it has proved difficult to erase unhappy memories of domestic repression or disaster from public consciousness, or to prevent the dissemination of unofficial histories. Research shows that omitting past events or persons from public commemoration does not guarantee they will be forgotten, especially if they are focal points of group identity; indeed, they may serve as the foundations for counter-histories. For example, the year 1959 is central to the Tibetan narrative of resistance to Chinese domination. Furthermore, even when official histories are forcibly and repeatedly imposed, such as through compulsory education and examinations, they may not necessarily be remembered or deployed as originally intended, particularly if they run counter to personal or community experiences. In fact, they may be used in ways that actually challenge the official narrative. Students in Tiananmen Square in 1989 saw themselves—not the CCP—as inheritors of the spirit of May 4th, 1919. Not coincidentally, May 4th radicalism has been somewhat downplayed in recent years, and its ninetieth anniversary this year astonishingly low-key.

Ruling regimes often seek to use history both to legitimize their political authority and to suppress dissent. Nevertheless, controlling the past is considerably more complicated than merely adding or deleting events from the historical record and commemorating or silencing them on key anniversaries. In China, 2009 will certainly not be the last year in which tensions arise between those who want to remember and those who would have them forget.

The Walter H. Shorenstein Asia-Pacific Research Center is pleased to announce that Mr. Byongwon Bahk, former Senior Advisor to President Lee Myung-bak of Korea, will join the Center as the recipient of the %fellowship1% in the Center's Korean Studies Program for 2009-2010 academic year.

Mr. Bahk served as the vice minister of the Ministry of Finance and Economy in Korea and was a senior advisor to President Lee Myung-bak briefly.  Bahk brings 24 years of experience in economic affairs.

While at the Center, Mr. Bahk will lead a research project on economic affairs of Korea in relations to the U.S., including organizing a policy-related conference that will bring Koreans, Americans, and potentially others from the region together to engage in high-level discussions aimed at producing a report for the policymaking community.  He will also teach a course and offer public lectures or seminars on his search at Stanford.

The Koret Fellowship, generously funded by the by Koret Foundation of San Francisco, was established at the Center in 2008 to bring leading professionals in Asia and the United States to Stanford to conduct research on contemporary U.S.-Korean relations, with the broad aim of fostering greater understanding and closer ties between the two countries.