Farming practices in China could be designed to simultaneously improve yields and reduce environmental damages substantially, according to a new study by Stanford biology professor Peter Vitousek and a team of his colleagues at China Agricultural University.

Vitousek is the Clifford G. Morrison Professor in Population and Resource Studies in the Department of Biology and is a faculty affiliate of the Center on Food Security and the Environment at Stanford University. He also is a senior fellow at the Stanford Woods Institute for the Environment and is a professor, by courtesy, in the School of Earth Science’s Department of Environmental Earth System Science.

The research paper, published in Nature, compared current farming practices for staple crops corn, wheat and rice in Eastern and Southern China to three alternative approaches:

• incremental improvements of the current method, aimed at boosting crop growth and improving environmental quality;

• a yield-maximizing approach with no regard to either financial or environmental costs; and

• an "integrated soil-crop system management" (ISSM) approach that used crop models to redesign the production system.

The integrated soil-crop system approach aims to tailor decisions like crop selection, planting, sowing, and nutrient management to each field’s conditions in order both to enhance yields and to minimize environmental damage.

Nitrogen fertilizer is used extensively in modern agriculture – and nowhere more than in China.  Overall, Chinese farmers overuse fertilizer, with much of it ultimately polluting the air and water and contributing to hundreds of thousands of premature deaths each year. The production and transport of fertilizer also contributes significantly to agriculture's share of greenhouse gas emissions that fuel climate change. 

In total, the team tested the four farming methods in 153 site-years of experiments between 2009 and 2012 in widely distributed sites within China’s regions of intensive agriculture. Of the four methods, the yield-maximizing approach produced the highest yields of corn, wheat and rice. Yields from ISSM treatment were a close second, reaching 97-99% of the levels seen in yield-maximizing fields. Crops grown in the ISSM approach also required much less fertilizer, and used it much more efficiently, resulting in nearly no wasted nitrogen and significantly lower greenhouse gas emissions.
 

Stanford professor Peter Vitousek with a team of colleagues in China at an agricultural experiment station.

 “This is exciting work, because the joint challenges of increasing agricultural yields and reducing the environmental costs of agriculture are particularly stark in China – which has less farmland than the United States, a population that’s four times greater, and really horrendous levels of air and water pollution,” Vitousek said.  “If we can combine much higher yields with much lower environmental consequences in China, there is real hope that those challenges can be met around the world.  It’s globally significant that agricultural science in China is meeting these challenges in fundamental ways, and it’s a pleasure to collaborate with our colleagues there.”

The authors predict that if farmers can reach even 80% of the yields seen in the study's ISSM test fields by 2030 (when China’s human population will reach its peak), on the same amount of land that Chinese farmers cultivated in 2012, grain production could then meet demand for both human and animal consumption. This would help ensure food security in China and make China’s role in global food markets to more deliberate and predictable. At the same time, nitrogen losses could be cut by nearly half, thereby saving many lives, and total greenhouse gas emission could fall by one quarter. Moreover, the ISSM approach could be applied in other areas of the world, where it would boost global yields of major grain crops on existing farmland, while simultaneously reducing nitrogen use, greenhouse gas emissions, and economic costs to farmers.

Contact:

Peter Vitousek: vitousek@stanford.edu, (650) 725-1866

Laura Seaman: lseaman@stanford.edu, (650) 723-4920

Hunger touches the lives of people throughout the world, from the affluent Bay Area to the most impoverished regions of rural Africa. Food security – the availability of plentiful, nutritious, and affordable food – is a pressing issue for rich and poor countries alike as the world population moves toward 9 billion by mid-century.

In her new book The Evolving Sphere of Food Security (Oxford University Press, August), Professor Rosamond Naylor takes a holistic approach to the question of how to feed the world. Naylor, a professor of environmental earth system science and director of the Center on Food Security and the Environment (FSE), convened 18 colleagues from across Stanford’s diverse disciplines to shed light on the interdependent issues that affect global food security.

Throughout its 14 chapters, and a foreword by former United Nations Secretary-General Kofi Annan, the book takes up two important questions: How does the challenge of achieving food security change as countries develop economically? And how do food and agriculture policies in one country affect nutrition, food access, natural resources and national security in other countries?

Collaboration across disciplines

Naylor, who edited the volume and co-authored several chapters, explained that The Evolving Sphere of Food Security is the first book of its kind to engage faculty and scholars from across Stanford’s campus on issues of global hunger.

Professor Rosamond Naylor

“This book grew out of a recognition by Stanford scholars that food security is tied to security of many other kinds,” said Naylor, who is also William Wrigley Senior Fellow at the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment. “Food security has clear connections with energy, water, health, the environment and national security, and you can’t tackle just one of those pieces.”

Stanford has a long history of fostering cross-disciplinary work on global issues. It is in this spirit that the idea for the book was born, Naylor said. The book weaves together the expertise of authors from the fields of medicine, political science, engineering, law, economics and climate science.

“Stanford was the ideal place for this project. A book like this exemplifies how collaborative, interdisciplinary research can be greater than the sum of its parts,” Naylor said. “We have painted a much more inclusive picture of food security than if we had approached these questions from only one discipline.”

Rooted in field research

Another unique feature of the book is that each author’s insights are shaped by years of hands-on research and policymaking experience around the world.

Several authors, for example, have been instrumental in shaping U.S. and global food policy for decades. Walter Falcon, professor emeritus of economics and the deputy director of FSE, traces his career as an agricultural economics advisor to the Indonesian government, where he witnessed the country’s dramatic improvements in combating hunger and poverty since the 1960s.

Political science professor Stephen Stedman recounts his experience as a security policy advisor to the United Nations during the 2000s. Recognizing that food insecurity can exacerbate civil conflict, weaken governments and threaten international stability, Stedman worked to integrate food security into traditional security agendas.

Other authors have spent many years working in East Asia, Africa, South America, the Middle East and Europe. As a whole, said Naylor, the team has conducted well over a hundred years’ worth of field research all over the world.

Challenges evolve as countries develop

A recurring theme throughout the book – also reflected in its title – is the evolving nature of the food security challenges countries face as they move through stages of economic growth. At low levels of development, countries struggle to meet people’s basic needs. For example, Naylor’s chapter on health, co-authored with Eran Bendavid (medicine), Jenna Davis and Amy Pickering (civil and environmental engineering), describes a recent study showing that poor nutrition and rampant disease in rural Kenya is closely tied to contaminated, untreated drinking water. Addressing these essential health and sanitation issues is a key first step toward food security for the poorest countries.

As nations rise above the bottom rungs of development, they encounter new challenges. Scott Rozelle, director of the Rural Education Action Program, warns that middle income countries like China now face a “second food security crisis” of widespread micronutrient deficiency. Recent rapid economic and agricultural advancements have largely solved the problem of supplying sufficient calories. But this progress masks what Rozelle describes as “hidden hunger,” or a lack of vitamins and minerals that impedes kids’ school performance and could slow China’s long-term growth. Even in rich countries like the U.S., said Naylor, malnutrition can be a drag on educational and economic performance.

Developed countries face other unique tradeoffs in the use of resources for food production. In his chapter on water institutions, Buzz Thompson, professor of law and co-director of the Woods Institute, explains that conflicts over water increase between smallholder and industrial users as countries develop. Eric Lambin, professor of environmental earth system science, and Ximena Rueda, research associate in earth sciences, offer the paradox that as countries grow wealthier, changing patterns of agricultural land use may actually worsen food security by fueling the spread of obesity and diabetes.

At its core, said Naylor, The Evolving Sphere of Food Security is about more than economic and policy trends. “The book puts a human face to food security, because hunger is an intensely human experience,” she said. “This book tells an integrated story about people’s lives, and how they are shaped by resource use and the policy process around global food security.”