Defining and Using the Concept of Sustainable Agriculture

Sustainability has recently become a buzzword for agricultural programs in education, extension, research, and government policy. For effective communications among those teaching, studying, and practicing agriculture, it is essential that there be some agreement as to the definition of the term sustainable agriculture. The definition should be general enough to accommodate th wide range of agricultural situations in which it will be applied, yet specific enough to provide criteria by which the sustainability of alternative systems may be judged. To allow the greatest combination of utility and flexibility, the definition should be "ends oriented" rather than "means oriented." This article presents one such definition, discusses everal definitions proposed by others, and attempts to clarify some concepts uch as "lowinput" often associated with the sustainability issue. WIDESPREAD in the of sustainINTEREST concept able agriculture is a relatively recent phenomenon. Government, academic, and business entities that ignored nonconventional systems a decade ago are now actively promoting the concept of sustainability in their programs. Many universities have recently offered new courses to address the issue of agricultural sustainability, while several have even developed a degree program in sustainable agriculture (Howell, 1989). Sustainability has become an educational and political buzzword, but one that means different things to different people. For effective communications among those teaching, studying, practicing, regulating, or patronizing agriculture, it is essential that there be some agreement as to the meaning of the term sustainable agriculture. Otherwise, government and private programs developed with the aim of promoting or subsidizing research on, and farmer transition to, sustainable agriculture might end up just promoting old standard practices under a new name. Likewise, without a suitable definition, students and instructors will not share a common understanding of what types of agricultural systems and approaches are appropriate for inclusion in courses addressing the subject. The definition must be general enough to accommodate Agronomy Dep., Univ. of Maryland, College Park, MD 20742. Contribution from the Dep. of Agronomy, Univ. of Maryland, College Park. Received 16 Oct. 1989. *Corresponding author. Published in J. Agron. Educ. 19:126-130 (1990). the wide range of agricultural situations in which it will be applied, yet specific enough to provide criteria by which the sustainability of a proposed system may be judged. This article presents one such definition, discusses several others, and attempts to clarify some concepts often associated with sustainable agriculture. BASIC CONSIDERATIONS The adjectives biological, ecological, alternative, regenerative, and low-input are commonly used to refer to seemingly similar concepts of agricultural systems. The term sustainable agriculture is herein defined broadly enough to include all of these concepts to some degree, and also address a specific set of criteria. In authorizing $3.9 million for research on sustainable/low-input agriculture in 1987-1988, the U.S. Congress specified two such criteria: that this agriculture should lower costs (thus presumably improve farm profits) and reduce negative impacts on soil and water resources (Madden and O’Connell, 1989). these criteria, Francis et al. (1987) adds the goal of least sustaining the current level of agricultural production. Three schools of thought on sustainability were noted by Lowrance et al. (1986) as being concerned with: food self-sufficiency, land stewardship, and preservation of rural communities. It could be argued, in addition, that to be sustainable in the long term, agriculture must provide society with quality food high in nutrition and taste value and free from potentially toxic pesticide residues. Authors such as Knorr and Vogtmann (1983) and Clancy (1990), therefore focus on food quality and human health as issues of sustainability. Thus, three broad areas of concern seem to underlie the concept of sustainable agriculture: (i) economic concerns over economic j ustice, the survival of owneroperated farms, and the long-term profitability of agriculture; (ii) environmental concerns over adverse impacts of agriculture on land, water, and wildlife resources; and (iii) public welfare concerns over food quality and human exposure to toxic chemicals. The degree of integration also sets the sustainable agriculture approach apart from more conventional approaches. A sustainable agriculture integrates all components of a system in the horizontal, vertical, and time dimensions. In the horizontal dimension, fieldscale systems must be analyzed for their implications at the farm, watershed, regional, and national levels ̄.. and vice versa (i.e., national policies must be eval126 J. Agron. Educ., Vol. 19, no. 2, 1990 uated in terms of their regional and farm-scale impacts, etc.). Lowrance t al. (1986) suggest that different types of considerations will predominate at different levels--agronomic at the field-scale, microeconomic at the farm-scale, ecological at the regional scale, and macro-economic at the national scale. In any case, the sustainability of a practice or program applied at one level must be judged in the context of its impacts at the more broad and narrow levels. For example, introducing cattle (Bos taurus) into a grainbased system at the whole farm level will result in changes in crop rotations and manure input at the field level, as well as changes in land-use patterns and nutrient cycles at the watershed and regional levels. Vertically, field-scale systems must be integrated with input supply, marketing, consumption, and disposal/ recycling.., and vice versa. Likewise, systems must be projected in the time dimension over entire rotations, and long-term (decades, centuries) resource and social cycles. In recognition of this, F.E. Hutchison, in opening an International Conference on Sustainable Agriculture at Columbus, OH, in 1988, remarked that the concept ofsustainability "simply adds a long-term time dimension to discussions on farming systems." Because agriculture involves site and situation specific processes, it is probably not possible to define sustainable agriculture in terms of specific sets of practices. Also, because sustainability is dependent on social, political, and economic factors, these factors cannot be divorced from the definition of sustainable agriculture (Altieri, 1986). By its biological and social nature, agriculture is not static. A sustainable agriculture must be capable of continually evolving, while preserving the social and natural resources upon which it is based. DEFINITION AND CRITERIA It may be of less importance to assess the sustainability of a system as currently practiced, than to assess the sustainability of changes proposed in the system. The underlying basis of the definition proposed here is that it is easier to judge the direction in which a new technology or policy will move an agriculture system than it is to judge the absolute sustainability of a system as it is. In December 1988 at the Annual Meetings of the American Society of Agronomy, Soil Science Society of America, and Crop Science Society of America, I had the privilege of facilitating a discussion group of about 250 agronomists that developed a definition of sustainable agriculture that could serve this purpose: "A sustainable agriculture is one that, over the long term, enhances environmental quality and the resource base on which agriculture depends; provides for basic human food and fiber needs; is economically viable; and enhances the quality of life for farmers and society as a whole" (Anon., 1989). Another definition proposed here, which is modified from Weil (1988), sets forth three sets of criteria by which the direction, toward greater or less sustainability, may be judged. To be judged sustainable, changes to the current system should be an improvement over present practice and policy by all three sets of criteria. The definition is as follows: An agricultural program, policy, or practice contributes to agricultural sustainability if it: 1. Enhances, or maintains, the number, quality, and long-term economic viability of farming and other agricultural business opportunities in a community or region. 2. Enhances, rather than diminishes, the integrity, diversity, and long-term productivity of both the managed agricultural ecosystem and the surrounding natural ecosystems. 3. Enhances, rather than threatens, the health, safety, and aesthetic satisfaction of agricultural producers and consumers alike. Using this definition, certain inputs or practices may be judged "sustainable" in one situation but not in another, or at one point in the evolution of a system, but not at a later point. Such a definition treats sustainable agriculture as a dynamic system and is operational despite our imperfect knowledge of the system. It can hopefully serve to guide agriculturalists and policy makers in their efforts to make agriculture more sustainable. It should be noted that both the ASA definition and that proposed here involve ends rather than means. A means-oriented definition would require prejudgment of certain types of practices (e.g., use of nitrogen fertilizers) and policies (e.g., price supports), hence would stifle creativity in government, in the marketplace and among individual farmers. Ideas for changes in policy and practice should be judged, on an ad hoc basis, by how well they meet the goals or "’ends" laid out in the