Successful farming has long depended upon the right mixture of plants, seeds, soil, water, weather, and luck. Facing a future of growing population and diminishing resources, the prospect of sustainable agriculture and secure food supplies will require the added ingredients of compromise and cooperation, according to international agricultural specialists.
The world faces looming food shortages as the human population swells, a problem that can best be solved by wedding the newest agricultural science and technology with the best sustainable farming methods, said Pamela C. Ronald, a professor of plant pathology at the University of California, Davis.
With limits on the amount of arable farmland and water available, feeding billions of humans will require greatly increasing the productivity of farming while minimizing its detrimental environmental impact, she said.
“How can we feed the world without destroying it?” Ronald said. “Agriculture needs our collective help and all appropriate tools if we are to feed the growing population in an ecological manner.”
Ronald made her remarks while delivering the 2011 Charles Valentine Riley Memorial Lecture at AAAS. Established in 2010, the lecture honors Riley, a prominent 19th century entomologist at the U.S. Department of Agriculture, and is endowed by the Charles Valentine Riley Memorial Foundation. A plant genetics expert noted for her work in engineering rice for resistance to disease and tolerance to flooding, Ronald is co-author of the book Tomorrow’s Table: Organic Farming, Genetics, and the Future of Food.
Moderating a discussion by an expert panel after the 21 June lecture, AAAS President Nina V. Fedoroff, a biology professor at Pennsylvania State University who specializes in plant stress response, said farming will need to double productivity in the coming decades, while reducing farming’s ecological impact. This will require many innovations in crop improvement, as well as better water management and more efficient nutrient use.
In her remarks, Ronald said world population is projected to surpass 9 billion by 2050. To feed so many without increasing plant yields, agricultural experts estimate the world would have to double its croplands by 2050, she said, which is not possible because most arable land is already in use. Much of the remaining land is marginal for farming. Compounding these problems is erosion, which over the past 40 years has rendered 30% of arable land unproductive. At a time when the world needs more farmland, we are losing it to erosion, she said.
Another challenge is fresh water, Ronald said. Half the world’s wetlands have disappeared, groundwater aquifers are being used at an unsustainable rate, and water tables in parts of Mexico, India, China, North Africa, and the United States are declining as much as one meter a year as demand continues to rise.
“Seventy percent of the world’s fresh water is already used for agriculture,” Ronald said. “This means that increased food production must largely take place on the same land area while using less water.”
Past agricultural productivity advances have partially relied upon combating insects and plant diseases with pesticides, some of which adversely affect human health. The World Health Organization estimates that between 3.5 and 5 million people globally suffer acute pesticide poisoning annually, resulting in 300,000 deaths and increased risk of diseases such as cancer in farm workers, she said.
Increased use of new seed and plant varieties, including those developed through genetic engineering, can help increase productivity while limiting negative environmental, economic, and social impacts of agriculture, Ronald said. But planting of higher-yielding, genetically improved seed that require less water and insecticides is not sufficient to address all agricultural challenges. Only by combining the use of improved seed with ecologically-based agricultural practices can sustainability be maximized, she said.
“The key point is that no matter how powerful the seed technology,” she said, “the seed must still be integrated with other strategies to manage the diverse spectrum of diseases and pests that attack a crop.”
To be successful, agricultural policies should be based on scientific evidence, said Ronald and others on the panel.
“After 14 years of cultivation and a cumulative total of nearly 2 billion acres planted,” Ronald said, “not a single instance of harm to human health or the environment has resulted from commercialization of genetically engineered crops.”
Fedoroff added that regulation of plants, animals, and other agricultural products should be based on their properties and not the method by which they are produced.
In the United States, for example, farms seeking official federal “certified organic” status are allowed to use “genetically improved” seeds developed through hybridization and other conventional approaches but not “genetically engineered” seeds.
Roland noted that the world’s leading experts—represented by the Indian, Chinese, Mexican, Brazilian, French, British, and American academies of science—have concluded that the genetically engineered crops currently on the market are safe to eat and safe for the environment. All methods of breeding introduce genetic changes with risk of unintended consequences. These risks are similar for conventional breeding and genetic engineering. For these reasons, she said, there is no scientific basis for ruling out genetic engineering as a tool for crop improvement.
Ronald said many more countries are exploring the use of genetically engineered crops. There are currently 30 commercialized genetically engineered crops cultivated worldwide and the number will grow to more than 120 by 2015, she said. Half will come from national technology providers in Asia and Latin America designed for domestic markets.
L. Val Giddings, a senior fellow with the Information Technology and Innovation Foundation, said resistance to genetically engineered crops is beginning to abate in Europe, where constraints and barriers to their use have been strongest. As results come in from more studies showing no evidence of greater risk from genetically engineered crops, he said, attitudes are changing.
“One of the most important barriers to overcome is dogma,” Giddings said. “The people will not tolerate being kept hungry.”
John D. Hardin Jr., owner of Hardin Farms, a grain and pork operation in Danville, Indiana, and a Purdue University trustee, said another concern about using genetically engineered and hybrid seed is cost and availability. A small number of companies now control such seed sources. Because genetically engineered seed must clear additional regulatory and legal requirements (compared to hybrid and other seed), it is complicated and expensive to bring these seeds to market, Hardin said, limiting access to large companies that can afford to pay the additional costs.
Mark Rosegrant of the International Food Policy Research Institute said there has to be more investment in agricultural research, particularly in populous developing countries so that more food can be grown locally.
This will cut the need and expense of importing so much food and generate income in rural areas. This effort should include investment in rural infrastructure development to improve access to markets and resources for local farmers.
Hardin noted that farming is more than just growing food. Agriculture means managing an ecosystem, he said, learning how to limit use of fertilizers and pesticides while adapting sustainable methods, such as limiting tilling or plowing of the soil to decrease erosion and using cover crops instead of artificial fertilizer to enrich soil.
Michael T. Clegg of the School of Biological Sciences at the University of California, Irvine, said current agricultural systems not only need to be made more efficient but more adaptable to changing conditions. Agricultural production increasingly will face new problems, he said, including coming climate change that will result not only in rising waters in coastal areas but also shifts in growing seasons and different rainfall and drought patterns in many areas.
Ronald stated that the polarizing debates on seed technologies versus farming practices were distracting from the key challenge—a healthy and productive agricultural system.
Ronald said she believes that discussions about agriculture must be framed in the context of the environmental, economic, and social impacts of agriculture —the three pillars of sustainable agriculture. Rather than focusing on how a seed variety was developed, she said, we must ask what most enhances local food security and can provide safe, abundant, and nutritious food to consumers.
The lecture was planned in cooperation with the World Food Prize Foundation and was sponsored by the U.S. Department of Agriculture’s Agricultural Research Service, Economic Research Service, and the National Institute of Food and Agriculture; Case IH; DuPont; Mars, Incorporated; and the Norman Borlaug Institute for International Agriculture.
Watch video highlights from Pamela C. Ronald’s 2011 Riley Lecture.
Learn more about the Charles Valentine Riley Memorial Lecture.
Watch a presentation by the 2010 Riley Lecturer Roger Beachy, director of the National Institute of Food and Agriculture.