Recently there has been a change in thinking among many agricultural leaders and researchers toward a major focus on agricultural sustainability. To make progress toward such sustainability requires a clear delineation of its concepts and components. In this paper, I attempt to clarify relevant concepts and terminology in an effort to facilitate communication and cooperation. I also recognize, however, the intense feelings involved in these definitions. More satisfactory definitions will come in time as research and practice continue.

This paper analyzes some of the potential problems that can be anticipated in putting a sustainable system together on an operating farm, and proposes a few of the principle practices and management strategies required for making such systems work.

The positive role of biological diversity in enhancing agricultural sustainability is presented in the context of crop rotation. Once common in virtually all farming systems, crop rotations have been simplified or eliminated during the past two decades from farming systems in most industrialized countries. Specialization, production intensification, government commodity programs, and the resulting short-term economic decisions have all had an influence in reducing crop rotation and diversity. Economic and environmental concerns have raised the question of agricultural sustainability in the public arena. We discuss here the role of diversity and crop rotation in relation to the sustainability issue, including matters of agronomic, economic, and environmental benefits, as well as increased efficiency in the use of fossil fuels. Constraints and future directions in the use of crop rotation in modern agriculture are described.

Livestock are important components of agricultural systems. In the U.S., one-half of total agricultural receipts come from the sale of livestock. They are the harvestors of range plants, forages, and crop residues; they level out the effects of the seasonally and variability of rainfall; they cushion disruptions in the trade and marketing of feed grains; they counteract declining soil fertility and soil erosion; and they contribute to the efficient year-round use of farm labor. Unfortunately, farmers are often not inclined to adopt alternative animal agriculture systems despite the advantages they may offer. Constraints that may be encountered include possibilities of reduced short-term profits, difficulties in adapting available technology to alternative farming systems, difficulties in shifting from specialized crop or livestock farms to crop/livestock farms, and the increased needs for labor and management. Some actions needed in the U.S. to improve livestock production in alternative farming systems are: the establishment of government policies to promote the shift of marginal lands to soil and water conserving crops and the incorporation of pastures and forages in crop rotations; research to improve the utilization by ruminants of ligno-cellulosic feeds (pastures, forages, crop residues); and programs to improve range and forest management and to lead to the development of systems that optimize the use of forages for the production of nutritionally desirable lean beef.

Conventional agriculture is increasingly criticized as being too concentrated in ownership; too reliant on technology, petroleum-based inputs, and credit; too specialized and ecologically unsound; and too dependent on government subsidies. Alternative agriculture is offered by many as an alternative, and we discuss the possible impacts of its widespread adoption on farm income, yields, regions, labor, trade, environmental quality, and farm structure. The profitability of alternative agriculture is also examined - in so doing, a distinction is made between the adoption of low-input practices and a more holistic alternative agricultural system.

U.S. agriculture, which has developed in a mixed environment of private initiative and government support, is very successful by many measures. American farmers produce record levels of food and fiber per farm worker at very low budgetary cost to consumers. Recently, however, concern about resource depletion and agrichemical pollution has caused critics to question the environmental sustainability of the agricultural production system. Furthermore, pressures to trim the growing contribution of agricultural subsidies to the national budget deficit have led legislators and others to question the sustainability of the federal farm programs. Low agrichemical input or sustainable agricultural practices, such as nitrogen-fixing legumes in rotation with cereals, could reduce environmental damage. The selectivity and structure of historical farm programs, however, have economically favored conventional systems. Farm programs subsidize only about half the total value of agricultural products. Feed and food grains, cotton, and dairy products receive the lion's share of payments. Soil-building crops like forage legumes, most edible legumes, hay, and pasture are excluded. Secondly, the structure of commodity programs favors intensive production of program crops supported by high fertilizer and pesticide applications. This incentive emanates from the policy of computing the farm-wide deficiency payment for a program crop proportionately to the farm's historical “base” acreage and “established” yield for the crop. The leading farm program crops of corn, wheat, cotton, and soybeans occupied slightly over 60 percent of cropped acres and received at least 65 percent of all U.S. agricultural pesticides and fertilizer in the mid 19809s. Despite budget pressures and environmental concerns, near term termination of farm programs or decoupling them from production of particular commodities is unlikely. Fears about aggravating financial stress, reducing land values, and harming agrichemical supply businesses in program crop-growing regions will promote cautious incremental change. Recent promising signs of “creeping decoupling” include the 1986 freeze on established yields, the gradual reduction in target prices, the permitting of multi-year grass or legume plantings as set aside acreage, and the loosening of base acreage restrictions within the 1988 Drought Relief Bill.

The adoption of sustainable farming system practices by U.S. producers could affect the international competitive position of many agricultural commodities, including livestock. The adoption of such practices over the next several decades will depend on commodity policy legislation, environmental regulation, commodity price and acreage diversion incentives, and the success of ongoing GATT negotiations and trade liberalization. However, the extent and magnitude of these effects are dependent on the internalization and recognition of social costs of agricultural production by farmers and explicit tradeoffs between environmental degradation and agricultural profitability. Environmental externalities include soil loss, surface and ground water contamination by agricultural residuals, loss of wildlife habitat, and diminished aesthetic amenities. In effect, both public and private concerns about the marginal social environmental costs associated with production, when present, will influence the shape and location of commodity supply curves and the U.S. export capability. In turn, these supply curves, which define the production capacity of the U.S. to meet domestic and export demand, will determine our comparative competitive positions for different commodities in world markets.

Complex policy issues and tradeoffs will arise in crafting the 1990 or 1991 Farm Bill. Efforts to advance progress toward sustainable agriculture production systems could arise in the farm bill's commodity, conservation, and research titles. Key definitional issues are highlighted here, as well as water quality issues and the impact of ongoing GATT negotiations in the context of increasing global demands on American agriculture.

The environment will be a major issue during the 1990 Farm Bill reauthorization, with environmental reform efforts directed toward strengthening the conservation provisions of the 1985 Farm Bill, and expanding into new areas of water quality and food safety. The process will differ from the 1985 Farm Bill environmental reform experience in several important ways. In 1990, the policy ideas under discussion are more sweeping, the issues are more complex and controversial scientific understanding is more ambiguous, technical capacity in the field is highly limited, and the farm policy environment is more volatile. Key environmental policy issues this year are the future size and purposes of the 1985 Conservation Reserve Program, and the strengthening of sodbuster, swampbuster and conservation compliance provisions enacted in 1985. Commodity program reforms that remove disincentives to crop rotations, and food safety issues will also top the environmental agenda. An Environmental Stewardship Program is proposed as a new approach to source reduction and pollution prevention. An ESP program might consist of 10–15 year contracts under which farmers are compensated to adopt environmentally sound practices such as crop rotations, reduced and more efficient use of agricultural chemicals, integrated pest management systems, and best management practices for water quality and food safety concerns.

Farmers committed to the overall goal of sustainability in agriculture have banded together to support legislative action favorable to that goal. Specific objectives relate to addition of organic amendments to soils to improve fertility, avoidance of excessive use of pesticides and synthetic fertilizers, crop rotation, species diversity among crops, protection of wildlife habitats, and support of family-operated farms. Currently applicable legislation is believed to be unfavorable to some of these objectives and needs modification.

Organic producers have traditionally understood the value of conserving the natural enemies of the pests of the crops they grow. An equal appreciation of the value of importing new species of natural enemies is also needed. Given this understanding, the interests of organic farmers could then be promoted by efforts to stimulate greater activity by government agencies in charge of such importations. Furthermore, the focus of such importations could be altered to target more precisely pests of crops most commonly grown by organic producers. This would benefit organic farmers by permanently solving or greatly reducing the intensity of problems from many introduced crop pests. The potential benefit of a coordinated federal and state program of classical biological control could be very large for organic farmers. There is an increasing interest nationwide in expanding the use of classical biological controls. Organic producers now have the opportunity to add their influence to this trend to reshape the country's pest control agenda away from chemicals and toward biological controls and to focus this at least in part on those pests of greatest concern to organic producers. To do so, however, organic producers will have to learn a new lesson, i.e., the difference between native and imported pests and the value of importation as a means to control the latter.

In the United States, trees constitute an element in agriculture whose importance has been inadequately appreciated. In actuality, they are highly important in several ways. From the time of the earliest settlements, they have served as a source of building materials and energy. They protect the soil against erosion by wind and water. When used as windbreaks adjacent to crop fields, they protect crops against the damaging effects of wind on crop yields. As windbreaks for livestock, they increase feed conversion efficiency, improve weight gains, and increase the survival rate ofnewborns. They provide habitat for wildlife and contribute aesthetically to the appearance of the countryside. They protect water resources. Trees need to have the story of their great benefits more widely and emphatically told.