Peter Nyaki has learned a thing or two about soil erosion. The soil on his tree and vegetable farm in Tanzania was losing nutrients and becoming less and less fertile, while his harvests were meager — until he tried a new approach, using organic manure and sowing grasses to prevent runoff during the rainy season. Now his small farm supports a variety of healthy crops, including beans whose harvests have increased more than 60 percent.
Nyaki is sharing what he has learned with fellow farmers in the Lushoto district. Some of his neighbors are trying out agricultural practices proven on his land. Nyaki is one of millions of farmers around the world who are making agriculture both more efficient and environmentally friendly by adopting sustainable practices. Sustainable agriculture promotes methods that are economically viable, environmentally sound and protect public health.
The path to sustainability
Farmers and the commercial food industry have made significant progress in feeding the world. Twenty-five years ago, 23 percent of the world’s population was undernourished. Today, says the United Nations, the figure is down to 13 percent.
But this achievement has come at a price: deforestation and habitat loss; depletion of scarce water resources; pollution of land and sea from farm runoff; soil erosion; and other soil problems. And greenhouse gas emissions from agriculture, forestry and fisheries have nearly doubled over the past 50 years.
The challenge: how to feed the 9 billion people expected in 2050 while preserving the environment and climate. In other words, produce 70 percent more food using less land and fewer resources.
Sustainable agriculture practiced consistently on a global scale can help farmers meet that challenge, says a team of international experts. “Sustainability is a necessity, not a luxury,” Jim Horne told the Freshgreens website. Horne heads the Kerr Center for Sustainable Agriculture in Poteau, Oklahoma, and co-authored The Next Green Revolution: Essential Steps to a Healthy, Sustainable Agriculture.
Harvesting more with less
“I see great movement toward a transition to sustainability,” Stanford University’s Pamela Matson told learner.org. “The key is that we’re going to have to move a lot faster.” Some governments, scientists and NGOs are helping farmers make this transition.
Crop rotation and drip irrigation use less water and little or no artificial fertilizer. No-till farming — a way of growing crops or pasture without disturbing the soil through tillage — could boost maize yields by 20 percent, and when combined with sustainable irrigation practices could bring the increase close to 70 percent.
Some of the new farming technologies employed by American farmers are exhibited at the 2015 Milan Expo’s U.S. Pavillion.
Farmer at the center
Sustainable agriculture can benefit farmers. Higher yields and lower fertilizer and pesticide cost mean higher income, and less exposure to harmful chemicals.
But farmers sometimes fear change, lack money or sufficient information, or distrust strangers telling them what to do. Farmer cooperatives and farmer field schools — networks for sharing ideas and knowledge — can help promote sustainable practices. Government officials can make it easier for farmers to make the switch.
When a Vietnamese official promoted the System of Rice Intensification (SRI), the result was more rice from less fertilizer and water.
International programs like the United States’ Feed the Future work to develop targeted climate-smart technologies and methods. Even agribusinesses and food companies can do their part. Corporations such as the Campbell Soup Company and General Mills are adopting sustainable practices in their supply chains. In India, Coca-Cola and a local NGO boost drip irrigation and other sustainable practices by training and equipping mango farmers in the state of Andhra Pradesh.
Seeds of change
Research is a key to further gains. Project Catalyst promotes farmer-driven innovations that reduce pesticide and fertilizer runoff into Australia’s Great Barrier Reef lagoon. In sub-Saharan Africa, where some farmers can barely afford fertilizer, many now “microdose,” or measure precisely the nutrients needed for each seed hole. Their high-tech tool: a simple bottle cap.
Over the next decade, researchers expect to breed plant varieties that use less fertilizer and produce higher yields.
The greatest hope, says Cornell University’s Norman Uphoff, lies in better understanding the role that billions of microorganisms play in plant and soil fertility. “We need an equivalent of the Copernican revolution to utilize the potential of those microorganisms,” he says.