Agriculture, Organic

Organic farming is a production system that sustains agricultural productivity while avoiding or largely excluding synthetic fertilizers and pesticides. Whenever possible, external resources, such as commercially purchased chemicals and fuels, are replaced by resources found on or near the farm. These internal resources include solar or wind energy, biological pest controls, and biologically fixed nitrogen and other nutrients released from organic matter or from soil reserves. Thus organic farmers rely heavily on the use of crop rotations, crop residues, animal manures, compost, legumes, green manures, off-farm organic wastes, mechanical cultivation, mineral-bearing rocks, and aspects of biological pest control to maintain soil productivity and tilth, to supply plant nutrients, and to control insect pests, weeds, and diseases. In essence, organic farming aims to promote soil health as the key to sustaining productivity, and most organic practices are designed to improve the ability of the soil to support plant and microorganism life.

In contrast, conventional farming is characterized by monoculture systems that are heavily dependent on the use of synthetic fertilizers and pesticides. Although such systems are productive and able to furnish low-cost food, they also often bring a variety of environmental effects such as pesticide pollution, soil erosion, water depletion, and biodiversity reduction. Increasingly, scientists, farmers, and the public in general have questioned the sustainability of modern agrochemically based agriculture. A large number of organic farmers do use modern machinery, recommended crop varieties, certified seed, sound livestock management, recommended soil and water conservation practices, and innovative methods of organic waste recycling and residue management. Clearly, though, there are sharp contrasts between organic and conventional agriculture.

Most management systems used by organic farmers feature legume-based rotations, the application of compost, and several diversified cropping systems, including crop-livestock mixtures. Through the adoption of such practices, organic farmers aim at:

building up soil organic matter and soil biota
minimizing pest, disease, and weed damage
conserving soil, water, and biodiversity resources
long-term agricultural productivity
optimal nutritional value and quality of produce
creating an aesthetically pleasing environment.

Features of Organic Farming

Organic farming is widespread throughout the world and is growing rapidly. In Germany alone there are about eight thousand organic farms occupying about 2 percent of the total arable land. In Italy organic farms number around eighteen thousand, and in Austria about twenty thousand organic farms account for 10 percent of total agricultural output. In 1980 the U.S. Department of Agriculture (USDA) estimated that there were at least eleven thousand organic farms in the United States and at least twenty-four thousand farms that use some organic techniques. In California, organic foods are one of the fastest-growing segments of the agricultural economy, with retail sales growing at 20 percent to 25 percent per year. Cuba was the only country undergoing a massive conversion to organic farming, promoted by the drop of fertilizer, pesticide, and petroleum imports after the collapse of trade relations with the Soviet bloc in 1990.

Given new market opportunities, farmers grow all kinds of crops, including field, horticultural, and specialty crops, as well as fruits and animals such as cattle, pigs, poultry, and sheep.

Although research on organic farming systems was very limited until the early 1980s, pioneering studies of R. C. Oelhaf (1978), the USDA (1980), W. Lockeretz and others (1981), D. Pimentel and others (1983), and the National Research Council (1984) on organic farming in the United States provide the most comprehensive assessments of organic agricultural systems. These studies concluded the following:

As farmers convert to organic farming, initially crop yields are lower than those achieved in conventional farms. In the corn belt, corn yields were about 10 percent less and soybean yields were about 5 percent less on organic farms than on paired conventional farms. Under highly favorable growing conditions, conventional yields were considerably greater than those on the organic farms. Under drier conditions, however, the organic farmers did as well or better than their conventional neighbors. Beyond the third or fourth year after conversion and after crop rotations became established, organic farm yields began to increase, so that their yields approached those obtained by conventional methods.

Conventional farms consumed considerably more energy than organic farms largely because they used more petrochemicals. Also, organic farms were considerably more energy-efficient than conventional farms. Between 1974 and 1978 the energy consumed to produce a dollar's worth of crop on organic farms was only about 40 percent as great as on conventional farms.

Studies conducted in the Midwest between 1974 and 1977 found that the average net returns of organic and conventional farms were within 4 percent of each other. Organic farms had a lower gross income by 6 percent to 13 percent, but their operating costs were less by a similar amount.

The USDA formulated Midwest farm budgets in order to compare crop rotations on organic farms with continuous conventional crop practices. The analysis assumed that yields on organic farms were 10 percent lower. In addition, rotations tie up part of the cropland with forage legumes, such as alfalfa; on conventional farms this land would be producing either corn or soybeans. Since corn and soybeans command a higher price, potential income is reduced in proportion to the amount of land tied up in forage legumes. In essence, organic farmers are turning part of their potential income into renewal of the soil (by adding organic matter) in order to assure sustainability of future crop production. The conventional system maximizes present income and is not as concerned about viewing soil as a long-term investment. In conclusion, although initially yields are likely to be lower in organic farms, variable costs are likely to be much lower. With little or no expenditure on agrochemicals, and the availability of premium prices for certain crops, the net result may be similar or higher gross margins for organic farmers.

Many organic farms are highly mechanized and use only slightly more labor than conventional farms. When based on the value of the crop produced, however, 11 percent more labor was required on the organic farms because the crop output was lower. The labor requirements of organic farmers in this study were similar to those of conventional farmers for corn and small grains, but higher for soybeans because more hand weeding was necessary. A number of other studies indicated that organic farms generally require more labor than conventional farms, but such needs can be kept to a minimum if hand weeding or handpicking of insects is not used. The labor required to farm organically is a major limitation to the expansion of some organic farms and an important deterrent for conventional farmers who might consider shifting to organic methods.

DISTINGUISHING CHARA CTERISTICS OF CONVENTIONAL AND ORGANIC FARMING
Characteristics	Conventional	Organic
Petroleum dependency	High	Medium
Labor requirements	Low, hired	Medium, family or hired
Management intensity	High	Low-medium
Intensity of tillage	High	Medium
Plant diversity	Low	Medium
Crop varieties	Hybrids	Hybrid or open pollinated
Source of seeds	All purchased	Purchased, some saved
Integration of crops and livestock	None	Little (use of manure)
Insect pests	Very unpredictable	Unpredictable
Insect management	Chemical	Integrated pest management, biopesticides, some biocontrol
Weed management	Chemical, tillage	Cultural control
Disease management	Chemical, vertical resistance	Antagonists, horizontal resistance, multiline cultivars
Plant nutrition	Chemical, fertilizers applied in pulses, open systems	Microbial biofertilizers, organic fertilizers, semi-open systems
Water management	Large-scale irrigation	Sprinkler and drip irrigation

In many ways, organic farming conserves natural resources and protects the environment more than conventional farming. Research shows that soil erosion rates are lower in organic farms, and that levels of biodiversity are higher in organic farming systems than in conventional ones. In addition, organic farming techniques tend to conserve nitrogen in the soil/plant system, often resulting in a buildup of soil organic nitrogen. Organically managed soils have more soil microorganisms and enhanced levels of potentially available soil nitrogen.

Conversion to Organic Farming

In order for farmers to become certified organic producers, they must complete a certification procedure. The United States and most European countries have created regulations that apply to the production and sale of organically grown produce. All organic produce must carry a quality mark authorized by the government and provided to farmers by legal organizations that conduct strong verification systems with on-site annual inspections. Farmers willing to convert to organic farming must adhere to specific production standards and can be certified as organic only after three years of strictly following such standards.

From a management perspective, the process of conversion from a high-input conventional management to a low-input (or low-external input) management is a transitional process with four marked phases:

Progressive chemical withdrawal
Rationalization of agrochemical use through integrated pest management (IPM) and integrated nutrient management
Input substitution, using alternative, low-energy inputs
Redesign of diversified farming systems with an optimal crop/animal assemblage so that the system can support its own soil fertility, natural pest regulation, and crop productivity.

During the four phases, management is guided in order to ensure the following processes:

Increasing biodiversity both in the soil and aboveground

Increasing biomass production and soil organic matter content

Decreasing levels of pesticide residues and losses of nutrients and water

Establishment of functional relationships between the various farm components

Optimal planning of crop sequences and combinations and efficient use of locally available resources.

It is important to note that the conversion process can take anywhere from one to five years depending on the level of artificialization or degradation of the original high-input system. In addition, not all input substitution approaches are ecologically sound, as it is well established that some practices widely encouraged by some organic farming enthusiasts (such as flame-weeding and applications of broad spectrum insecticides) can have serious side effects and environmental impacts.

For scientists involved in transition research, an important outcome of these studies is the realization that the process of converting a conventional crop production system that relies heavily on synthetic, petroleum-based inputs to a legally certifiable, low-external input, organic system is not merely a process of withdrawing external inputs, with no compensatory replacement or alternative management. Considerable ecological knowledge is required to direct the array of natural flows necessary to sustain yields in a low-input system.

Miguel Altieri

Bibliography

Altieri, Miguel A. Agroecology: The Science of Sustainable Agriculture. Boulder, CO: Westview Press, 1995.

Gliessman, Stephen R. Agroecology: Ecological Processes in Sustainable Agriculture. Chelsea, MI: Ann Arbor Press, 1998.

Lampkin, N. Organic Farming. Ipswich, UK: Farming Press Books, 1990.

Lockeretz, W., G. Shearer, and D. H. Kohl. "Organic Farming in the Corn Belt." Science 211 (1981): 540-47.

National Research Council. Alternative Agriculture. Washington, DC: National Academy Press, 1984.

Oelhaf, R. C. Organic Agriculture. New Jersey: Allanheld, Osmon and Co. Pub., 1978.

Pimentel, D., G. Berardi, and S. Fost. "Energy Efficiency of Farming Systems: Organic and Conventional Agriculture." Agriculture, Ecosystems and Environment 9 (1983): 359-72.

Pretty, J. N. Regenerating Agriculture: Policies and Practice for Sustainability and Self-reliance. London: Earthscan, 1995.

Report and Recommendations on Organic Farming. Washington, DC: U.S. Department of Agriculture, 1980.

Youngberg, G. "Organic Farming: A Look at Opportunities and Obstacles." Soil and Water Conservation 35 (1980): 254-63.