Throughout history, agriculture has had a significant effect on the worlds landscape. Agricultural production has caused greater environmental change to the biosphere than any other land use (Gliessman 1998). Pimental et al. (1992) estimated that 50% of the worlds land is used for agriculture and animal production while only 5% is unmanaged lands, parks and preserves.
Most of the ACE Basin is a rural agricultural area with large tracts of privately owned open and wooded land. Open land is mostly used for crop and livestock production, the wooded land is mostly pine plantation and hardwood mixes. Twenty-three percent of land cover in Colleton county is in farms, of which one-third is in active cropland. The contribution of farming to the local economy is declining, as it is in rural communities nationwide. Colleton County now ranks 33 out of 46 South Carolina counties in terms of cash receipts from crops, livestock and livestock products. Only 167 of 416 farms in the county in 1997 were considered fulltime farms, down from 209 in 1992 (ERS 1997b). (See related section: Agriculture.)
A closer look at farm products shows that crop sales account for 76% of market value and livestock sales make up the remaining 24% (ERS 1997b). The vast majority of acres in crops were in corn, followed by soybeans, hay and winter wheat. There has been an increase in vegetable farms in the upper reaches of the County, including watermelon and cantaloupe. The only recorded crop increase between 1992 and 1997 was in the production of cotton. Cattle make up the bulk of the livestock in Colleton County farms, followed by hogs and pigs. An increase in the number of farms with sheep and lambs was the only increase in livestock production data. Another notable finding from the USDA 1997 Census of Agriculture is that although number of farms declined, and the cropland harvested declined, acreage (land in farms) increased by 23% from 51,142 hectares (126,370 acres) in 1992 to 62,659 hectares (154,829 acres) in 1997 (U.S. Department of Agriculture 1997).
Until the industrial revolution of the early to mid-1900's, farming practices were relatively environmentally friendly. Traditional farms were small-scale, used biological controls of pests and diseases, used crop rotation to maintain soil nutrients, included buffer zones at field edges, and involved little or no heavy machinery. The modernization of farming practices around the 1950's, resulted in extreme increases in productivity often to the detriment of environmental quality.
Modern, or conventional, agricultural practices use intensive tillage, monoculture, irrigation, application of inorganic fertilizers, chemical pest control, and plant genome modification to maximize profit and production (Gliessman 1998). These practices greatly increased crop yields, and agricultural production rose steadily after World War II. These conventional agricultural practices, however, have numerous long-term ecological impacts such as soil degradation, habitat alteration, water quality impacts, species composition impacts, and adverse effects of irrigation.
Overview of Farming in the Local
Farmers must find a way of being competitive and profitable while protecting environmental quality and investing in the natural resource base upon which their enterprise and the local economy depend. These sometime conflicting motivations explain how difficult are the issues that many farmers face. For example, although erosion control can provide onsite productivity benefits to farmers and reduce off-site environmental damages, new approaches can increase production costs by idling or retiring cropland, substituting more expensive production practices or requiring the purchase of new equipment (ERS 1997b).
Farming is a risky business. Critical factors of production, such as weather and market price are mostly out of the control of the farm operator. For this reason, government has been and must continue to be a partner, mitigating risk where possible. Government programs are essential in providing information, incentives, cost-sharing and when necessary regulations to help farmers maintain a balance between profitability and environmental impact. But government programs may not always have the impacts intended. For example, Colleton County has seen a decline in productive, tillable land in large part due to government programs which provide incentives to landowners to put land in conservation and wildlife habitat protection programs. For example, absentee landlords can get $30 to $40 an acre as incentive to plant and manage pine plantations, but not nearly that much a return on crop production.
While animal agriculture in South Carolina has grown steadily but slowly, the industry has seen rapid expansion in neighboring states of North Carolina and Georgia. The increase in jobs and income for residents of those states however have been accompanied by increasing environmental concerns and quality of life issues. South Carolina has the opportunity to learn from the experiences of its neighbors and grow an animal agriculture industry that is environmentally sound and a good neighbor to South Carolina residents.
Fragmentation of the landscape can have a number of effects (Saunders et al. 1991). It can:
Fragmentation often increases the amount of edge habitat in an ecosystem. Edge habitat can act as a buffer zone to moderate the changes in wind flow, moisture levels, temperature, and solar radiation that are characteristic of croplands so as to diminish impacts of farming on natural ecosystems. These buffer zones provide habitat that can be used for human activities while protecting undisturbed habitat. Edge habitats are also important for the propagation and protection of natural biological control agents of agricultural pests (Gliessman 1998).
One of the most significant habitat alterations of agriculture has been loss of wetland habitats. Almost half of the wetlands in the contiguous United States have been converted to other uses. Conversion of land for agriculture is responsible for 80% of all wetland losses since colonial times. Between 1954 and 1975, 81% of the wetlands converted in the US were used for agriculture (ERS 1997a). Recently, the importance of wetland functions has become better understood. Wetlands provide critical wildlife habitat for birds and other animals, temporary stormwater storage, groundwater recharging, pollution control, and recreational activities (ERS 1997a). The myriad functions that wetlands perform make it imperative that these habitats are protected from future conversion to other uses.
One consequence to species composition of conversion of lands to agricultural uses could be especially important in the ACE Basin study area. Bayne and Hobson (1997) found that conversion of forested areas to agricultural uses had serious effects on nesting birds because predation on groundnests increased along the edges and within the interior of forests adjacent to agricultural fields. Because the ACE Basin is an important breeding area for many species of birds, converting natural ecosystems to agricultural uses could significantly affect these bird populations.
Of these, erosion is the most widespread (ERS 1997a). In North America, soil is lost to wind and water erosion at a rate of 5-10 tons per hectare per year (2-4 tons per acre per year) but is replaced at only 1 ton per hectare (0.4 tons per acre) annually (Gliessman 1998). Erosion rates are greatly increased by conventional tillage practices in which fields are plowed several times a year. This practice leaves soil free of any cover for extensive periods and increases rates of wind and water erosion (Gliessman 1998).
Soil degradation also occurs from compaction caused by heavy machinery and cattle trampling. Compaction can make tillage costly, impede seedling emergence, and increase runoff and erosion (ERS 1997a). Salination degrades soil by increasing dissolved salt concentrations. Salination of soils can become especially problematic in irrigated areas. Irrigation waters contain dissolved salts that become concentrated in the soil as water is used and evaporates. An increase in salinity can result in decreased yields for such sensitive plants as soybeans, corn, and rice (ERS 1997a). Biological degradation is probably the most serious form of soil degradation. Biological degradation affects the microbial community of the soil, which are the primary decomposers, and can alter nutrient cycling, pest and disease control, and chemical transformation properties of the soil (ERS 1997a).
Agricultural practices cause more water pollution than any other single source (Gliessman 1998). Runoff from farms can contain sediment, pesticides, and fertilizers as well as animal waste products.
In Colleton County, the number of farms using pesticides increased slightly between 1982 and 1992 but the actual acreage that was sprayed decreased by 40%. In general, pesticide use declined between 1982 and 1992 for all of the counties within the ACE Basin study area (See Agricultural chemicals applied to farmlands ).
In Colleton County, as well as other counties within the ACE Basin study area, fertilizer use decreased on croplands from 1982 to 1992, although fertilizer use on pasturelands increased in most cases.
Animal Waste Products
In Colleton County, cattle and swine are the most abundant livestock raised. Between 1982 and 1992, the number of cattle declined by approximately 25% in Colleton County, but the number of swine raised remained constant.
Agriculture accounts for a majority of water use in the United States and more specifically in the ACE Basin study area. Agriculture uses water wastefully because more than half of the water intended for crops is never taken up by the plants (Gliessman 1998). Irrigation practices can have a number of ecological impacts. Irrigation can greatly increase soil erosion. Where water is dammed, dramatic ecological changes can occur. Where water is drawn from rivers, as is the case in the Edisto River sub-basin, competition with wildlife for this resource can occur. Irrigation practices where groundwater is removed faster than it is replaced by rainfall can cause land subsidence and if near the coast, saltwater intrusion. Extensive irrigation can also lead to changes in local climate. When water is transferred to fields, evaporation rates increase, and this can change humidity levels and rainfall patterns (Gliessman 1998).
In the ACE Basin study area, crop irrigation is on the rise. In Colleton County, the acreage of irrigated croplands increased by almost 70% between 1982 and 1992. Increases in irrigated lands also occurred in Charleston, Dorchester, and Beaufort Counties (See Acreage of land irrigated ).
Conventional farmers have highly specialized cropping systems that rely on substantial amounts of synthetic crop nutrients and pesticides.
Sustainable farmers limit use of synthetic fertilizers or pesticides, employ farm-produced resources and cultural management, raise more diverse crops and livestock, and express commitment to environmental sustainability.
To reduce the negative impacts of agriculture on natural ecosystems, society can: (1) impose regulations; (2) invest in research and development to find alternative production methods; or (3) encourage adoption of sustainable practices through education, technical assistance, and subsidies (ERS 1996). All three of these alternatives are currently being practiced in the US, although sustainable farming still makes up only a very small component of agriculture production in this country. But concerns about the loss of family farms, negative environmental impacts of conventional methods and the decline of rural communities have motivated a surge of interest in alternatives to conventional and agribusiness approaches.
Sustainable agriculture encompasses any farming system that minimizes inputs of non-renewable resources. Its goal is long-term agricultural sustainability and profitability for the farmer (Draeger 1990). Sustainable agriculture was first introduced in the United States around 1911, but industrialization along with government subsidies encouraged farmers to use conventional agricultural methods (Reganold et al. 1990). However, recent concerns about the environmental and economic impacts of conventional farming are encouraging farmers to adopt more traditional practices. Traditional methods are considered more sustainable because they: (1) maximize yield without exploiting the environment; (2) depend on local conditions and resources instead of using external inputs to attempt to control the environment; (3) emphasize nutrient recycling and minimizing negative impacts on the environment; and (4) maintain diversity (Gliessman 1998).
The goals of sustainable agriculture are to:
Negative impacts on the environment can be minimized by replacing the use of synthetic pesticides and fertilizers with ecologically sound management practices such as integrated pest management, nutrient management, irrigation water management, animal waste management, and tillage management (ERS 1997a, Gliessman 1998).
Modern agriculture is highly dependant on external inputs for materials, energy, and technology. Continued dependence on these inputs leaves farmers susceptible to shortages, market fluctuations, and price increases (Gliessman 1998). Sustainable agriculture strives to limit the dependence on external inputs. Biological controls replace synthetic mass-produced pesticides, crop residue management and animal waste management replace the use of fossil fuel based fertilizers, and crop rotation replaces monoculture cropping which is often highly dependent on commercial seed producers. Also, by removing dependence on external inputs, farmers practicing sustainable agriculture focus more on local conditions, local ecosystems, and locally-adapted crop plants as well as maintain experience-based knowledge and a connection with the land (Gliessman 1998).
Research into agriculture practices continues to yield new information about how to farm more sustainably. A few practices which are not only economically beneficial but that are also environmentally friendly include crop residue management, crop rotation systems and measures to manage water quality. A 1997 survey by the American Farmland Trust found that most farmers had not suffered any loss of value due to government regulations such as zoning, erosion control or wetlands protection (American Farmland Trust 1998). The survey also found that a majority of farmers are willing to share the costs of protecting the environment with the public.
Nutrient and Pest Management
Integrated pest management (IPM) uses biological controls such as natural predators and parasites to control pests and, therefore, results in decreased reliance on pesticides. IPM practices are used on approximately (10118 hectares) 25,000 acres of farmland in Colleton County to control pests. Nutrient management involves determining how much nutrient is needed, timing the application of nutrients to the biological needs of the crop so less is available to runoff, and eliminating broadcast application whenever possible (ERS 1997a). Nutrient management is used on approximately 15% of the crop lands in Colleton County.
Crop Residue Management
Crop residue management is also essential in maintaining soil health and preventing soil erosion. These practices leave at least 15% crop residue on the field after planting to control water erosion or at least 561 kg/hectare (500 pounds per acre) of crop residue to control wind erosion (ERS 1997a). Approximately 1214 hectares (3,000 acres) of cropland are tilled by conservation methods in Colleton County. Crop residue management systems include conservation tillage practices intended to provide sufficient residue cover to help protect the soil surface from the erosive effects of wind and water (Bull and Sandretto 1996). About 35 percent of the US planted crop acreage now relies on conservation tillage. Recent increases in conservation tillage are expected to continue because there are a variety of economic advantages of this method over conventional systems. In addition to achieving the initial goal, which is reduction of soil erosion, the benefits of this method include fuel and labor savings, lower machinery investments, and long-term benefits to soil structure and fertility (Bull and Sandretto 1996). Reports note that machinery designed specifically for conservation tillage is now more readily available. Farmers tend to implement conservation tillage at their own expense, once they learn of the economic and environmental advantages.
Some questions do remain whether the adoption of crop residue management leads to environmental benefits in all regions, and whether it is profitable in all cases. Factors include whether crop residue management reduces total costs of production, and the effect it has on crop yields. Though decreasing the intensity of tilling operations reduces labor and machinery costs, there may be additional chemical costs to achieve needed yields. This is just one example of the many tradeoffs farmers face in choosing the best farming approach given natural conditions, advantages and limitations (ERS 1997b).
Crop Rotation Systems
Crop rotation systems reduce farms dependence on external inputs through internal nutrient recycling, maintenance of long term productivity of the land and breaking weed and disease cycles (Gebremedhin and Schwab 1998). Crop rotation can also improve soil health and prevent erosion. Including legumes in the crop rotation on a regular basis can increase nitrogen levels in the soil and decrease the amount of synthetic fertilizers required. Crop rotations can control soil erosion because certain crops included in the rotation (i.e. wheat, barley, and oats) provide additional vegetative cover to reduce erosion (ERS 1997a). Crop rotation is the most widespread agricultural conservation practice in Colleton County with over one-third of the croplands using this practice. In the ACE Basin study area, soil erosion rates did not change much between 1982 and 1992, with a maximum decrease of only 1.2 tons per hectare per year (0.5 tons/acre yr) (USDA, undated).
A direct economic benefit of crop rotation is an increase in crop yield. Crop rotation systems can also improve soil quality and fertility, thereby reducing the need to purchase fertilizer. In comparative profitability performance research, most crops show increased profitability in rotation versus being grown as a continuous crop (Gebremedhin and Schwab 1998). Since the main economic factor that determines a farmers cropping system choice is the rate of return, crop rotations will prevail over continuous cropping only if shown to be more profitable. For example, in Iowa a corn-soybeans-corn rotation was shown to yield $98 more per hectare ($40 more per acre) than continuous corn (ERS 1997b).
Larger forces of change guiding these trends include technological advances, changes in consumer demands for food, changes in processing, profitability of economies of scale in production, and price instability (Clemson University 1998).
The aspects of animal agriculture that most affect citizens are water pollution and air pollution, usually in the form of unpleasant odors. More regulation of this growing industry will most likely occur in the coming years. The challenge for a young industry in South Carolina is to anticipate new federal regulations and use technology advances to keep the industry sustainable and profitable. In some cases, technological advances can reduce costs as well as pollution. Animal waste containers such as lagoons or ponds should be inspected regularly for damage and the level in containers should be kept low enough to prevent overflow during heavy rains (DeFrancesco 1997). Almost 2% of the farms in Colleton County utilize waste management in their operations.
There are a variety of federal programs at the Environmental Protection Agency and the Department of Agriculture to help farmers finance improvements in waste management, pollution control, and conservation planning.
Industry-wide trends affect agriculture in the ACE Basin. Low commodity prices and mergers of major agribusiness and agrichemical companies forecast a more difficult future for local family farms. The market demand for organic farming and sustainable agriculture is still so small and unreliable that farmers are reluctant to make such changes in operations. Opportunities made by technological advances, such as crops for pharmaceuticals and genetic engineering of some crops like corn for various purposes, could hold some potential for ACE Basin farmers. Niche marketing of products may be the only way small farms can survive. In the meantime, many landowners are turning to creative ways to supplement their farming income. There has been an increase in fee-hunting, leasing hunting rights as an additional source of income. The need for supplemental income has also sparked another trend. In the southern end of Colleton County farmers are finding that real estate developers are willing to pay attractive prices for their land. Agriculture as a way of life will continue to decline until residents and leaders decide to make generating economic opportunities through farming a priority for the community (M. Barnes, pers. comm.).
Although sustainable agriculture appears to address many of the concerns presently surrounding farming, problems still exist that hinder farmers from converting to sustainable agriculture. Problems of sustainable agriculture include:
Some experts estimate that only 40,000 to 90,000 farmers are practicing sustainable agriculture in the U.S. - about 2% of the nation's total (Reganold et al. 1990). The private benefits of conservation are often insufficient to induce farmers and ranchers to protect natural resources at levels that are optimal from a social perspective (ERS 1997a). Until natural resources are considered to be as valuable as economic returns by society, sustainable agriculture will continue to be the exception instead of the normal agricultural practice.
Technical assistance concerning sustainable agriculture is available to farmers through their local Conservation district office as well as Extension Services. These agencies provide assistance on a variety of agricultural issues and allow exchange of information among farmers. The USDA also provides a variety of conservation plans that are designed to encourage conservation of natural resources.
Research and development of new agricultural technologies is conducted by both the private and public sectors. The majority of research on natural resources and the environment is conducted by USDA in cooperation with State Agriculture Experiment Stations. Research by these agencies centers on soil science, water, land management, forestry, pollution control, and other research (ERS 1997a). Unfortunately, monies allotted for this research are low - only 15% of the public funds allocated for agricultural use in 1994 were for natural resource management (ERS 1997a).
American Farmland Trust. 1998. Farming on the edge. American Farmland Trust, Washington, DC.Barnes, M. personal communication. Clemson University Extension Service, Colleton County. 1999.
Bayne, E.M. and K.A. Hobson. 1997. Comparing the effects of landscape fragmentation by forestry and agriculture on predation of artificial nests. Conservation Biology 11(6):1418-1429.
Boutin, C. and B. Jobin. 1998. Intensity of agricultural practices and effects on adjacent habitats. Ecological Applications 8(2):544-557.
Bull, L. and C. Sandretto. 1996. Crop residue management and tillage system trends. Natural Resources and Environment Division, Economic Research Service, U.S. Department of Agriculture, Statistical Bulletin No. 930, Washington, DC.
Center for Rural Affairs Newsletter. 1993. Planting the future: Sustaining land and communities. Walthill, NE.
Clemson University. 1998. Animal agriculture in South Carolina: A fact book. Clemson University, Clemson, SC.
DeFrancesco, D. J. 1997. Farming for clean water in South Carolina: A handbook of conservation practices. South Carolina Department of Natural Resources, Division of Land and Conservation Districts, and U.S. Department of Agriculture, Natural Resources Conservation Service. Columbia, SC.
Dicks, M. R. and K. C. Buckley (eds.). 1989. Alternative opportunities in agriculture: Expanding output through diversification. Commodity Economics Division, Economic Research Service, U.S. Department of Agriculture, Agricultural Economic Report No. 633, Washington, DC.
Draeger, C.L. 1990. Sustainable agriculture at work. Journal of Soil Water Conservation 45(1):83-85.
Economic Resources Service. 1996. Agriculture and water quality. http://www.econ.ag.gov/briefing/wqbrief/index.htm#TWO
Economic Resources Service. 1997a. Agricultural resources and environmental indicators, 1996-97. U.S. Department of Agriculture, Economic Research Service, Natural Resources and Environment Division. Agricultural Handbook No. 712, Washington, DC.
Economic Resources Service. 1997b. Farm Business Economics Report, 1995. U.S. Department of Agriculture, Rural Economy Division, Economic Research Service, ECI-1996, Washington, DC.
Gebremedhin, B. and G. Schwab. 1998. The economic importance of crop rotation systems: Evidence from the literature. Department of Agricultural Economics, Michigan State University, East Lansing, MI.
Gliessman, S.R. 1998. Agroecology: Ecological processes in sustainable agriculture. Ann Arbor Press, Chelsea, MI.
Hallberg, G.R. 1986. From hoes to herbicides: Agriculture and groundwater quality. Journal of Soil Water Conservation 41(6):357-364.
Heimlich, R.E. and C. H. Barnard. 1995. Economics of agricultural management measures in the coastal zone. Natural Resources and Environment Division, Economic Research Service, U.S. Department of Agriculture, Agricultural Economic Report No. 698, Washington, DC.
Pimental, D., U. Stachow, D.A. Takacs, J.W. Brubaker, A.R. Dumas, J.J. Meaney, J.A.S. ONiel, D.E. Onsi, and D.B. Corzilius. 1992. Conserving biological diversity in agricultural and forestry systems. Bioscience 42:354-362.
Reganold, J.P., R.I. Papendick, and J.F. Parr. 1990. Sustainable agriculture. Scientific American 262(6):112-120.
Saunders, D.A., R.J. Hobbs, and C.R. Margules. 1991. Biological consequences of ecosystem fragmentation: A review. Conservation Biology 5(1):18-32.
U.S. Department of Agriculture. undated. National Resources Inventory website. http://www.nhq.nrcs.usda.gov/land/meta/m2031.html. Accessed 1999.
U.S. Department of Agriculture. 1997. Census of agriculture, county profile for Colleton County, South Carolina. www.nass.usda.gov:80/census/census97/profiles/sc/sc.htm. Accessed 1999.
Yarrow, G.K. 1990. Wildlife management: Farms and woodlands. Clemson University Cooperative Extensive Service, Clemson, SC.