In a lecture to the Stanford community Tuesday night, Professor Sir Gordon Conway argued that sustainably intensifying agriculture, especially in Africa, is the only way to feed a growing global population without greatly expanding the amount of land used for farming. Sir Gordon is an agricultural ecologist and was an early pioneer of sustainable agriculture while working in Malaysia in the 1960s. He is now a professor of international development at Imperial College London and the director of Agriculture for Impact, a project funded by the Bill and Melinda Gates Foundation.

Sir Gordon's lecture, "Can Sustainable Intensification Feed the World?" was the second installment of the Food and Nutrition Policy Symposium Series sponsored by the Center on Food Security and the Environment.

Sir Gordon described three major challenges to ensuring future global food security: food prices are higher and more volatile, one billion people are malnourished (including 1 in 5 children), and rising demand means that 60 to 100 percent more food will be needed to feed the world by 2050. Solving the food security crisis will mean improving both the quantity and the nutrition of food, at stable and affordable prices, in the face of major challenges.

These challenges include factors on the demand side of the global food economy, such as population growth, changing diets, and the use of crops for biofuels. Supply side factors like high fertilizer prices, climate change, and scarcity of land and water put even more pressure on the food system. 

The solution, Sir Gordon said, is agricultural intensification, a set of practices that allow farmers to produce more food with existing land and water. Sustainability is a key component, so that intensification does not also raise greenhouse gas emissions, deplete soil quality, or damage the resilience of farming systems. Sustainable intensification will be especially important in Africa, said Sir Gordon, where population growth and dietary changes will be most dramatic, and where currently crop yields are far below most other areas of the world.

 Farmers, scientists and policymakers can take several approaches to sustainable intensification. An ecological approach includes practices that safeguard environmental resources and reduce farmers’ dependence on chemicals like herbicides and pesticides, such as through organic farming, integrated pest management, agroforestry or conservation agriculture. A genetic intensification approach includes developing better plant varieties, with traits that promote more sustainable agriculture by resisting pests and diseases, or that provide more nutrition. A third approach is socio-economic intensification of agriculture, through the development of farmers’ cooperatives, better links between farmers and markets, and improved access by farmers to insurance and credit.

The goal, Sir Gordon said, is to help farmers “build resilient livelihoods” that will withstand economic and environmental shocks in the coming decades. Good science is important, but strong political leadership, especially within Africa, will be just as crucial.

In a recent speech, Stanford professor Rosamond Naylor examined the wide range of challenges contributing to global food insecurity, which Naylor defined as a lack of plentiful, nutritious and affordable food. Naylor's lecture, titled "Feeding the World in the 21st Century," was part of the quarterly Earth Matters series sponsored by Stanford Continuing Studies and the Stanford School of Earth Sciences. Naylor, a professor of Environmental Earth System Science and director of the Center on Food Security and the Environment at Stanford, is also a professor (by courtesy) of Economics, and the William Wrigley Senior Fellow at the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment.

"One billion people go to bed day in and day out with chronic hunger," said Naylor. The problem of food insecurity, she explained, goes far beyond food supply. "We produce enough calories, just with cereal crops alone, to feed everyone on the planet," she said. Rather, food insecurity arises from a complex and interactive set of factors including poverty, malnutrition, disease, conflict, poor governance and volatile prices. Food supply depends on limited natural resources including water and energy, and food accessibility depends on government policies about land rights, biofuels, and food subsidies. Often, said Naylor, food policies in one country can impact food security in other parts of the world. Solutions to global hunger must account for this complexity, and for the "evolving" nature of food security.

As an example of this evolution, Naylor pointed to the success of China and India in reducing hunger rates from 70 percent to 15 percent within a single generation. Economic growth was key, as was the "Green Revolution," a series of advances in plant breeding, irrigation and agricultural technology that led to a doubling of global cereal crop production between 1970 and 2010. But Naylor warned that the success of the Green Revolution can lead to complacency about present-day food security challenges. China, for example, sharply reduced hunger as it underwent rapid economic growth, but now faces what Naylor described as a "second food security challenge" of micronutrient deficiency. Anemia, which is caused by a lack of dietary iron and which Naylor said is common in many rural areas of China, can permanently damage children's cognitive development and school performance, and eventually impede a country’s economic growth.

Hunger knows no boundaries

Although hunger is more prevalent in the developing world, food insecurity knows no geographic boundaries, said Naylor. Every country, including wealthy economies like the United States, struggles with problems of food availability, access, and nutrition. "Rather than think of this as 'their problem' that we don't need to deal with, really it's our problem too," Naylor said.

She pointed out that one in five children in the United States is chronically hungry, and 50 million Americans receive government food assistance. Many more millions go to soup kitchens every night, she added. "We are in a precarious position with our own food security, with big implications for public health and educational attainment," Naylor said. A major paradox of the United States' food security challenge is that hunger increasingly coexists with obesity. For the poorest Americans, cheap food offers abundant calories but low nutritional value. To improve the health and food security of millions of Americans, "linking policy in a way that can enhance the incomes of the poorest is really important, and it's the hard part,” she said.” It's not easy to fix the inequality issue."

Success stories

When asked whether there were any "easy" decisions that the global community can agree to, Naylor responded, "What we need to do for a lot of these issues is pretty clear, but how we get after it is not always agreed upon." She added, "But I think we've seen quite a few success stories," including the growing research on climate resilient crops, new scientific tools such as plant genetics, improved modeling techniques for water and irrigation systems, and better knowledge about how to use fertilizer more efficiently. She also said that the growing body of agriculture-focused climate research was encouraging, and that Stanford is a leader on this front.

Naylor is the editor and co-author of The Evolving Sphere of Food Security, a new book from Oxford University Press. The book features a team of 19 faculty authors from 5 Stanford schools including Earth science, economics, law, engineering, medicine, political science, international relations, and biology. The all-Stanford lineup was intentional, Naylor said, because the university is committed to interdisciplinary research that addresses complex global issues like food security, and because "agriculture is incredibly dominated by policy, and Stanford has a long history of dealing with some of these policy elements. This is the glue that enables us to answer really challenging questions." 

Children in rural Kenya are more susceptible to disease and death the farther away they live from clean drinking water, according to Stanford researchers.

In a survey of families in Asembo – a small farming community at the edge of Lake Victoria that has high rates of chronic diarrhea, child malnutrition and child death – a research team from the Center on Food Security and the Environment found that most people live just over a quarter-mile from clean water sources. About 200 feet closer to home are ponds and springs contaminated with E. coli bacteria. Sixty-six percent of families primarily use this contaminated surface water for drinking.

A child in Asembo, Kenya sits next to her family's water storage containers.

A child in Asembo, Kenya sits next to her family's water storage containers. Photo Credit: Amy Pickering

While water is essential for farming, collecting it is time-consuming and physically exhausting in remote places like Asembo. Previous research has shown that when families must travel long distances for water, child health suffers. The harder it is to collect, the less of it a family will use. A shortage of water for cooking and drinking compromises children’s nutrition and hydration. And it limits hand washing and bathing, making children more susceptible to disease. Quality and availability of water also varies widely from source to source, and the time required to collect water can force families to use dirtier, unimproved water sources that are closer to home. 

In 2011, the FSE researchers partnered with the Centers for Disease Control Kenya Medical Research Institute (CDC-KEMRI), which was already conducting an extensive survey of household-level health indicators in the region. Combining resources with CDC-KEMRI allowed the team – led by FSE Director Rosamond Naylor, a professor of environmental earth system science, and Jenna Davis, an assistant professor of civil and environmental engineering – to use a robust set of data. The information covered about 3,000 households in a five kilometer radius and was collected on a bi-weekly basis for six months. In exploring the links between water, food and health in Asembo, FSE researchers first expanded the definition of water “access” to account for both physical distance and the quality of water sources.

Researchers take a child's measurements in Asembo, Kenya.

Researchers take a child's measurements in Asembo, Kenya. Photo Credit: Amy Pickering

Researchers then mapped the distance of each household from its nearest water source, and recorded whether the source was improved (such as a deep borewell) or unimproved (surface water like a pond, spring or shallow well). To get the most precise possible data on local water quality, the research team collected samples from each household’s water source and sent them to a local hospital lab for testing. Surveyors then collected data on each household’s water management practices, including water treatment. They measured agricultural output, dietary diversity, and perceived food insecurity, then recorded the weight and height measurements of each child in the household. Respondents also reported the frequency of recent cases of diarrheal disease among children of the household.

Results of the initial survey highlight sobering realities about water access in Asembo. Households in the survey reported average per capita water consumption of only 31 liters per day, including water used for cooking, drinking, hygiene and agriculture. The average walk time to the nearest water source was approximately 15 minutes. The average distance to the nearest improved source was 428 meters, whereas the average distance to unimproved surface water was 374 meters. Water quality tests confirmed that these sources, used by the majority of families, were highly contaminated with E. coli bacteria, while improved water sources were significantly cleaner. Thirty percent of children showed stunted growth, and 11 percent were underweight for their age.

A researcher collects a sample of stored water at a household in Asembo, Kenya.

A researcher collects a sample of stored water at a household in Asembo, Kenya. Photo Credit: Amy Pickering

Researchers found that close proximity to an abundant water source, regardless of quality, correlated with an increase in food production and diversity, as well as a lower hunger score. Having enough extra water for crop irrigation clearly improves children’s diets – particularly their access to the micronutrients essential for normal physical and cognitive development – and helps them resist disease. Households further from water sources reported lower and less diverse crop yields, as well as poorer child health indicators. Quality was also an important factor, as households with access to clean, improved water reported better child health outcomes than those relying on contaminated surface water.

The ultimate goal of the project, “Rural health and development at the food-water nexus” is to design interventions and policy incentives that help people absorb nutrients in environments where food and water are limited and disease is prevalent. In the next stage of the project, researchers will focus on links between water access and the progression of HIV, and will also investigate how improved diets from better water access can impact household income.

About the Stanford Research Team:

Jenna Davis is Associate Professor of Civil and Environmental Engineering, Higgins-Magid Faculty Senior Fellow at the Stanford Woods Institute for the Environment, and an affiliate of the Center on Food Security and the Environment.
Rosamond Naylor is the Director of the Center on Food Security and the Environment, Professor of Environmental Earth System Science, and the William Wrigley Senior Fellow at the Stanford Woods Institute.
Eran Bendavid is an infectious diseases physician and Assistant Professor of Medicine in the Division of General Internal Medicine, as well as an affiliate of the Center on Food Security and the Environment and the Stanford Health Policy center.
Amy Pickering is a lecturer in the School of Earth Sciences, and a research associate in Civil and Environmental Engineering, the Woods Institute for the Environment, and the Center on Food Security and the Environment.
Glwadys Gbetibouo is a postdoctoral scholar at the Center on Food Security and the Environment.
Katrina ole-MoiYoi is a Ph.D. student at the Center on Food Security and the Environment.