SUSTAINABLE AGRICULTURE. From a technological and economic standpoint, agriculture today represents one of the success stories of the modern era. Despite an ever increasing global population, and a corresponding gradual decrease in the availability of nonrenewable natural resources such as energy, land, and water, farmers throughout the world have responded to the challenge by increasing total and per area production levels every year. This agricultural miracle is due to a long tradition of farmer self-reliance, ingenuity, and perseverance, and to the support provided to farmers by many private and public institutions. Especially noteworthy is the support provided by a network of agricultural research universities in North America and Europe. Furthermore, crop productivity has improved in the developed world, and in many Third World countries as well. By the 1970s, many Third World countries in Asia and Latin America had actually reached self-sufficiency with respect to several primary staple grains.
The race toward increased crop yields began in the mid-to late 1800s in precapitalist England. Ever since then, scientists, environmentalists, and economists have issued words of caution concerning environmental and social issues arising from modern agriculture. By the midto late twentieth century, some of the more negative environmental and economic side effects of modern capital-intensive agriculture became evident in many parts of the world. The increased realization that modern agriculture had serious side effects, resulting in reduced environmental quality, health concerns, and economic insecurity for the traditional family farm, led in part to what is known today as a global "Sustainable Agriculture" movement.
Because agricultural systems are so diverse, based on farm size, location, crop being grown, socioeconomic background, among many other factors, and because the movement has become so widespread globally, sustainable agriculture has come to represent different things to different people. Nevertheless there are some common threads, concepts, and beliefs. In the most general terms, sustainable agriculture describes systems in which the farmer reaches the goal of producing adequate yields and good profits following production practices that minimize any negative short-and long-term side effects on the environment and the well-being of the community. The major goals of this approach are thus to develop economically viable agroecosystems and to enhance the quality of the environment, so that farmlands will remain productive indefinitely.
Why Sustainable Agriculture? History and Future Prospects
Ancient history, ranging from the Egyptians to the Romans to the Mayans, indicates that poorly managed agriculture can lead to the eminent decline of entire civilizations. By the midpart of the twentieth century, symptoms began to appear, documented by scientists, that some aspects of modern agriculture were unsustainable, leading in many cases to a decline in environmental quality and human quality of life. The undesirable side effects of modern agriculture, some believed, were threatening the lands and the very livelihood that farmers were trying to sustain. In contrast, from a historical perspective, scientists knew that civilizations that did follow sustainable practices were indeed able to thrive for centuries. Thus, by incorporating the use of production techniques developed by the latest agricultural research, along with some of the farming practices that proved effective through centuries of farming in many areas, a set of recommended management practices was established in individual production regions.
The future goal of farming communities is to strive to use current sustainable practices and to utilize the latest production techniques to remain competitive in the global agricultural market. For this to take place, a close communication link has to be maintained between rural communities, researchers, and society at large. This link gives urban communities a better understanding of issues affecting farmers, including the farmers' role as stewards of the environment, and of the economic realities of providing the public with a consistently healthy and safe food supply.
Implementing Sustainable Systems
An important aspect of sustainable agriculture is that it does not represent a specific set of agricultural practices that farmers need to follow step by step, like one would a recipe, to reach a specific goal. Instead, the concept represents more of a paradigm shift that encourages farmers to seek their own path, one that best fits the farm's particular conditions, and leads toward a more environmentally friendly approach without sacrificing yields or profits. Similarly, sustainable agriculture is not a specific target, but instead is more of a process that every farmer pursues as part of the daily farm operations. Thus, because agricultural systems are so diverse, farmers may choose among a myriad number of agricultural practices and techniques available to produce crops more effectively.
See also Agriculture since the Industrial Revolution ; Agronomy ; Crop Improvement ; Ecology and Food ; Environment ; Green Revolution ; Greenhouse Horticulture ; High-Technology Farming ; Horticulture ; Organic Agriculture ; Organic Farming and Gardening ; Organic Food ; Tillage ; Water: Water as a Resource .
Carson, Rachel. Silent Spring. Greenwich, Conn.: Fawcett Crest, 1962.
Collins, Wanda W., and Calvin O. Qualset, eds. Biodiversity in Agroecosystems. Boca Raton, Fla.: CRC Press, 1999.
Gliessman, Stephen R. Agroecology: Ecological Processes in Sustainable Agriculture. Chelsea, Mich.: Sleeping Bear Press, 1998.
Gliessman, Stephen R. Agroecosystem Sustainability: Developing Practical Strategies. Boca Raton, Fla.: CRC Press, 2001.
Hatfield, J. L., and D. L. Karlen, eds. Sustainable Agriculture Systems. Boca Raton, Fla.: Lewis Publishers, 1994.
National Research Council. Sustainable Agriculture and the Environment in the Humid Tropics. Washington, D.C.: National Academy Press, 1987.
Powers, L. F., and R. McSorley. Ecological Principles of Agriculture. Albany, N.Y.: Delmar, 2000.
Some Key Undesirable Side Effects of Modern Agriculture
- Unsustainable irrigation programs throughout the world are resulting in an undesirable buildup of salinity and toxic mineral levels in one out of five hectares under irrigation. Thus, agricultural water, a nonrenewable resource whose use has tripled globally since 1950, has to be used more efficiently to minimize salinization problems.
- Excessive soil erosion, in the range of fifteen to forty tons per hectare annually, results in the loss of productive farmland in many parts of the world. Forested areas, a refuge for wildlife and biodiversity (biological diversity), are then often turned into agricultural fields to compensate for the loss of the abandoned eroded areas.
- The indiscriminate use of pesticides is affecting human health and wildlife populations, as first reported to the population at large in Rachel Carson's book Silent Spring (1962).
- The increased concentration of farms into larger and larger farm holdings is reducing the number of small family farms, believed by many to represent the heart of rural communities and to be key stewards of the environment.
- The trend toward larger farms and plantation-type monocultures is leading to a loss of global biodiversity. Biodiversity, many argue, may be a critical ecological feature that allows the continued survival of humans on earth.
- The excessive reliance on synthetic fertilizers, and the improper use and disposal of animal wastes is leading to the breakup of natural nutrient cycles. This causes an undesirable buildup of nutrients and salts in aquifers, affecting wildlife in aquatic habitats.
What Is Sustainable Agriculture? Some Key Definitions
Sustainable agriculture involves farming systems that are environmentally sound, profitable, productive, and compatible with socioeconomic conditions (J. Pesek, in Hatfield and Karlen, Sustainable Agriculture Systems ).
Agroecology is a field of research used to implement sustainable systems. It is the application of ecological concepts and principles to the study, design, and management of sustainable systems.
A systems approach is used to study and research sustainable systems. The goal is to study the farm as an entity made up of all its components and their interrelationships, together with relationships between the farm and its environment.
Key components of sustainable systems include enhanced internal nutrient cycling on the farm; improved soil quality through additions of organic matter and reduced soil erosion; increased vegetational diversity to promote natural systems of pest control; and alternative marketing programs that increase profits and minimize overhead costs.
Basic Features and Concepts of Sustainable Systems
- The need to maintain or improve soil quality and fertility. This is often attained by increasing the organic matter content of the soil, and by minimizing losses from soil erosion.
- Production programs are designed to improve the efficiency of resource utilization. This will result in the most cost-effective use of water, fertilizers, and pesticides.
- An attempt is made to improve internal nutrient cycles on the farm, which will reduce the dependence on external fertilizers.
- Efforts are made to improve biological diversity on the farm. This will result in improved natural suppression of pests, and may also help to improve internal nutrient cycling within the farm.
- Farm management and marketing programs are designed to minimize overhead costs and to increase returns, often by following alternative marketing schemes.
Thanks to a complex international system of production, processing, shipping, and marketing, people today can eat a vast selection of out-of-season and out-of-region fruits and vegetables year round. In addition, modern farming practices have provided an abundant, not just a varied, food supply. However, the availability of abundant and varied food relies on energy-intensive, nonrenewable resources such as fossil fuels, and many practices associated with agribusiness have had a detrimental impact on the environment.
Agribusiness looks at farms as factories to be run as profitably and efficiently as possible. "How much, how fast" replaces the old values of carrying capacity (how much the land can yield without being depleted) and a season of lying fallow. Monocropping (fields used for only one crop, the same crop year after year, commonly wheat, soybeans or cotton) and increased field size do away with biodiversity and hedgerows, and thus with fertility, pollinators, and resistance to insects and disease.
Effects of fertilizers.
Millions of tons of chemical fertilizers applied to fields destroy microorganisms that are vital to the health of the soil. The intensive use of herbicides and pesticides kills pollinating insects that are essential for crop production. Manure and crop residues, once valuable sources of soil nutrition, are no longer tilled in and have become polluting waste products themselves, to be burned or dumped. Underground aquifers (natural water reservoirs) that took thousands of years to fill are pumped dry to irrigate fields in semi-arid regions.
Additionally, ground water is full of dissolved mineral salts. As the water evaporates it leaves a salt concentration buildup that is poisoning the soil. Intensive plowing opens up hundreds of thousands of acres of topsoil to erosion by wind and rain, filling the air with dust or silting up waterways.
Loss of biodiversity.
As more and more wild land is converted to growing one particular crop on a massive scale, genetic biodiversity diminishes. Rain forests are bulldozed to provide pastures for cheap beef. Massive feedlot operations are susceptible to catastrophic diseases, and they pollute drinking water supplies with their tons of confined manure.
Agribusiness also affects the economy. Family farmers are increasingly replaced by corporate managers, and the price of farm equipment and capital outlay soars. Profits from production may go to a large company based far away from the actual farm and never enter the local economy. In addition, large-scale food production and distribution have become vulnerable to the vagaries of international politics and the stock market, and any breakdown in the network places everyone at risk. The price of oil, interest rates, trucking fees, politics and the weather all affect the availability and price of food. In countries where there is economic or military chaos, even though there might be plenty of food on farms or at food aid centers, the breakdown in the complex distribution system results in famine.
Sustainable agriculture is the practice of working in concert with nature to replenish the soil in order to assure a secure, affordable food supply without depleting natural resources or disrupting the cycles of life. Proponents of sustainable agriculture suggest we can reverse the damage done by agribusiness. They believe that a dependable long-term food supply must rely on the protection of resources—seeds, food species, soil, breeding stock, and the water supply, as well as the farmer who knows and cares for a particular piece of land and the community with which the farmer is interdependent. Sustainable agriculture promotes regional and local small-scale farms that rely on the interplay of crops and livestock to replenish the soil and control erosion. The aim of a healthy farm is to produce as many kinds of plants and animals as it reasonably can. Ordered diversity is the practice of maintaining many kinds of plants and animals together to complement one another.
The practice of planting a noncommercial crop on fields to increase fertility, conserve soil moisture, keep topsoil from eroding or blowing away and encourage soil microrganisms is called cover cropping. Soil fertility, which is the major capital of any farm, can be largely maintained within the farm itself by this method and by plowing back in manure and other organic wastes. Food grown for local consumption is more fresh, can be harvested when ripe, and uses less energy to get to market. Farm stands and local farmers' markets provide more money for the farmer and higher quality, lower-price food for the consumer.
Diversity of methods.
Sustainable agriculture embraces diversity of method and scale, looking for what is appropriate to a given location. One example is urban homesteading, in which thousands of vacant inner-city lots can be used to grow neighborhood gardens. Renewable energy sources, such as passive-solar greenhouses or windmills, are encouraged. Sustainable agriculture advocates organic solutions to pest control such as crop rotation, the introduction and maintenance of beneficial insects, and intercropping (growing more than one kind of crop on the same land in the same growing season). All these methods discourage insect infestations, thus reducing the amount of pesticides in the environment.
Agriculture cannot survive for long at the expense of the natural systems that support it. And a culture cannot survive at the expense of its agriculture.
see also Farming.
Organic Farming Research Foundation. Winter 2001 Information Bulletin, no. 9. Erica Walz, ed. Santa Cruz, CA: Organic Farming Research Foundation, 2001.
Because of concerns over pesticides and nitrates in ground-water , soil erosion , pesticide residues in food, pest resistance to pesticides, and the rising costs of purchased inputs needed for conventional agriculture, many farmers have begun to adopt alternative practices with the goals of reducing input costs, preserving the resource base, and protecting human health. This is called sustainable agriculture.
Many of the components of sustainable agriculture are derived from conventional agronomic practices and livestock husbandry. Sustainable systems more deliberately integrate and take advantage of naturally occurring beneficial interactions. Sustainable systems emphasize management, biological relationships such as those between the pest and predator, and natural processes such as nitrogen fixation instead of chemically intensive methods. The objective is to sustain and enhance, rather than reduce and simplify, the biological interactions on which production agriculture depends, thereby reducing the harmful off-farm effects of production practices.
Examples of practices and principles emphasized in sustainable agriculture systems include:
- Crop rotations that mitigate weed, disease, insect, and other pest problems; increase available soil nitrogen and reduce the need for purchased fertilizers; and, in conjunction with conservation tillage practices, reduce soil erosion.
- Integrated pest management (IPM) that reduces the need for pesticides by crop rotations, scouting weather monitoring, use of resistant cultivars, timing of planting, and biological pest controls.
- Soil and water conservation tillage practices that increase the amount of crop residues on the soil surface and reduce the number of times farmers have to till the soil.
- Animal production systems that emphasize disease prevention through health maintenance, thereby reducing the need for antibiotics.
Many farmers and people of rural communities are starting to explore the possibilities of systems of sustainable agriculture. The term "systems" is used because there is no one single way to farm sustainably. The possible ways are as numerous as farmers and potential farmers.
The first aspect of sustainable agriculture is the understanding that a respect for life, in its various forms, is not only desirable but necessary to human survival. A second aspect requires that the farming system not put life in jeopardy, and that its methods not deplete the soil or the water or place farmers in situations where they themselves are depleted, either in numbers or in the quality of their lives.
Another aspect of sustainable agriculture recognizes that farming families are an essential part of a sustainable system. Farmers are the systems' stewards, or caregivers. As stewards, they know their land better than anyone else and are equipped to shoulder the challenge of developing a sustainable system on that land. In a sustainable system, farmers ideally move toward less dependence on off-farm purchased inputs and more toward natural or organic materials. This is accomplished by gaining knowledge about the intricate biological and economic workings of the farm. Lastly, sustainable agricultural systems require the support of consumers as well; they can give support, for example, by selectively buying food raised in close proximity to a buyer's local market.
[Terence H. Cooper ]
National Research Council Board on Agriculture. Alternative Agriculture. Washington, DC: National Academy Press, 1989.
Thesing, C. "What Is Sustainable Agriculture?" The Land Stewardship Letter 10 (1992): 13–14.