(3) the "nonpoint" nature of erosion and agrichemical runoff, which makes it difficult to identify exact sources of pollution and to remedy pollution problems; and (4) the perception that farmers lack adequate economic incentives to undertake conservation practices that may yield benefits only in the long term, such as improved soil productivity, or to other parties, such as downstream users. Some soil conservation measures both prevent pollution and control it. For example, field terraces control erosion by retaining sediment already displaced above the terrace. At the same time, terraces also help prevent erosion by retarding the rate at which rainfall flows over a field. Grassy strips lining a streambank, in contrast, do not prevent erosion, but they do help prevent the pollution of water from sediment and agrichemicals. Measures such as conservation tillage help prevent erosion, but they can present tradeoffs in the form of increased use of pesticides to control weeds and insects. This traditional emphasis on voluntary action shifted to some extent with passage of the 1985 Food Security Act. Title XII, in particular, incorporated an unprecedented system of incentives and penalties to help address growing concern over agriculture's impact on the environment at large. Water pollution and degradation of fish and wildlife habitat are just two examples of these "off-site" impacts. Several of the Title XII programs help to prevent pollution, because they constrain activities that would result in erosion and related pollution problems. However, they do so by taking existing or potential cropland out of production altogether. For example, the Conservation Reserve Program has converted nearly 34 million acres of cropland to long-term vegetative cover for 10year contract periods in exchange for annual payments and costsharing assistance to establish cover and other practices. Sodbuster provisions prohibit cropping on designated lands without approved conservation plans under penalty of forfeiting federal commodity program payments. Swampbuster provisions prohibit conversion of designated wetlands to produce crops. Thus, these three programs do not focus on preventing wastes through more efficient agricultural practices. Emergence of Pollution Prevention Recent developments, however, are encouraging a pollution prevention approach in agriculture primarily through the reduction of agricultural inputs. The developments include (1) growing public concern for the amount of chemicals in food supplies and in the environment in general; (2) an accumulation of research findings and case studies pointing to the benefits of low-input agricultural methods; (3) increasing costs of pesticides as well as restrictions on specific pesticides as a result of the EPA accelerated pesticide registration process; (4) increasing resistance of insects to pesticides; and (5) an expanding number of federal and state programs aimed at researching and demonstrating the effects of low-input agriculture. While some farmers have always used pollution prevention practices, the incentives described above are encouraging expanded applications. Referred to variously as "alternative" or "sustainable" agriculture, low-input sustainable agriculture (LISA) has potential for reducing environmental damages associated with intensive agricultural practices. The LISA goals are consistent with the concept of pollution prevention: to conserve resources, reduce environmental damages, and promote food safety while being productive and profitable for the farmer. To accomplish these goals, LISA uses a combination of methods tailored to the needs of each crop and farm. Low-input agricultural practices include crop diversification, integrated pest management, crop rotations, use of animal manure and leguminous crops, mechanical cultivation, cover crops, strip cropping, alternative animal disease prevention strategies, and a variety of other measures. The Administration's 1991 budget proposals include a $28 million increase devoted to the U.S. Department of Agriculture's efforts to better understand the causal linkage between production practices and water quality degradation. Protection of the nation's water resources from contamination by agricultural chemicals and nutrients is a key priority of the Administration. The 1991 budget funds the second year of a Water Quality Initiative proposed by the President to promote the development and adoption of environmentally sensitive farm production practices and safer chemical and biological pest controls. In total, the budget provides over $300 million for this purpose. Ultimately, farmers must be responsible for changing production practices to avoid contaminating ground and surface waters. Federal and state governments can provide valuable information and technical assistance to producers, however, so that such environmentally sensitive techniques can be implemented at minimum cost. The proposed increase in the FY 1991 budget will allow the Soil Conservation and Extension Services to expand their efforts to transfer to farmers scientific information about the vulnerability of natural resources to chemical pollution. Demonstration projects targeted to particularly environmentally sensitive geographic regions will receive the highest priority. 54 Potential of Low-Input Agriculture Much of the discussion of LISA's merits can be attributed to a 1989 National Academy of Sciences report entitled Alternative Agriculture. While findings were based on selected case studies rather than systematic research, the authors were nonetheless enthusiastic about the potential of LISA, reporting that: "Farmers successfully adopting these systems generally derive significant sustained economic and environmental benefits. Wider adoption of proven alternative systems would result in even greater economic benefits to farmers and environmental gains for the nation."55 One NAS case study is highlighted below to illustrate the use of alternative practices. An Iowa farming couple grow corn, soybeans, oats, and hay on their 300-acre farm, in addition to raising livestock. The family has experimented with a variety of LISA methods over the years. For example, because ridge tillage and mechanical cultivation are used to control weeds, herbicides are rarely used. Some techniques have multiple benefits. Cover crops control weeds and protect the soil; soil erosion on the farm is 1-4 tons/acre/year (tpa), compared to a county average of 8-10 tpa. Crop rotations also control insects and improve yields. For example, the farm yields 130-150 bushels/acre of corn (versus the county average of 124) for $75/acre less than the conventional farm. Using an assortment of methods, the family is able to raise healthy cattle and hogs with little use of antibiotics.56 Field Monitoring in Low-Input Careful monitoring of field conditions is a tool in the cost-effective reduction of overall applications of fertilizers, pesticides, and irrigation water. For example, soil tests can be used to determine which fields need fertilizers and at what levels. "Scouting" for threshold levels of pests is the monitoring device used in integrated pest management (IPM). Rather than spraying as a preventative measure or upon first observation of a pest, chemicals are used only when the potential damage of a pest exceeds the cost of applying the pesticide. Benefits from irrigation efficiency extend far beyond conserving scarce water supplies—a major advantage in itself for many regions. Irrigation runoff can contaminate wetlands and waterways with damaging concentrations of salt, pesticides, and various toxic elements, such as cadmium and selenium that occur naturally in desert soils. Such pollution problems have increased significantly in tandem with the doubling of farmland under irrigation since 1945. A 3-year demonstration project sponsored by INFORM tested the potential of one method to conserve irrigation water in California. Small electronic devices, called gypsum blocks, were used to monitor increases in soil moisture caused by irrigations and decreases caused by crop water consumption. Project participants found the costs for gypsum blocks and labor amounted to about $2 per acre. Resulting benefits from lower water and energy costs and improved yields were found to amount to $50 or more per acre. As noted by the researchers: Sometimes the gains from using the method can be spectacular: An INFORM test on one strip of a 160-acre alfalfa field indicated that by using about 30 percent less water on the entire field the farmer could have earned $20,000 or more in higher hay yields alone.57 Federal and State Programs to Promote Various federal and state programs testify to the surge of interest in low-input sustainable agriculture. The 1985 Farm Bill authorized for the first time a grant program specifically for LISA-related research and education. Congressional appropriations thus far amount to $3.9 million in FY 1988 and about $4.4 million per year in FY 1989 and FY 1990 to fund projects. One project, costing about $200,000 in federal and matching funds, investigates the possibility of substituting legume crops in place of fallow cropland in Great Plains wheat production. Growing legumes with grains in humid areas has been shown to reduce soil erosion, fix atmospheric nitrogen, reduce pesticide and fertilizer inputs, reduce weed competition, and increase net return per acre. However, traditional legumes have not been popular in semi-arid conditions, because they compete for water needed by the next wheat crop. The project is investigating alternative species that need less water. 58 Integrated Pest Management (IPM) programs in the U.S. Department of Agriculture have a much longer history than LISA. The Extension Service received its first $500,000 IPM appropriation in 1972, largely in response to the environmental concerns raised in Rachel Carson's landmark book, The Silent Spring. Funding gradually increased to a peak of $7.5 million in FY 1981, and it has since continued at about 7.1 million per year. The success of IPM in the 1980s is attributed largely to the proven economic benefits accruing to many farmers.59 In 1987 the Appropriate Technology Transfer for Rural Areas (ATTRA) program initiated a toll-free service (800-346-9140) to provide information on low-input sustainable agriculture. The service is receiving increasing numbers of inquiries, with a total of about 9,000 calls received to date.60 States also are undertaking initiatives to explore and demonstrate the potential for low-input agriculture. A prime example is found in Iowa, where legislation enacted in 1989 authorizes at least five model farm demonstration projects across the state.61 While all projects are intended to implement in |