 |
| Agriculture |
| General |
Agribusiness · Agricultural science
Agronomy · Animal husbandry
Extensive farming
Factory farming · Free range
Industrial agriculture
Intensive farming
Organic farming · Permaculture
Sustainable agriculture
Urban agriculture |
| History |
History of agriculture
Arab Agricultural Revolution
British Agricultural Revolution
Green Revolution
Neolithic Revolution |
| Types |
Aquaculture · Dairy farming
Grazing · Hydroponics
Livestock · Pig farming
Orchards · Poultry farming
Sheep husbandry |
| Categories |
Agriculture
Agriculture by country
Agriculture companies
Biotechnology
Farming history
Livestock
Meat industry
Poultry farming |
 Agropedia portal |
| v · d · e |
Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm. Organic farming excludes or strictly limits the use of manufactured fertilizers, pesticides (which include herbicides, insecticides and fungicides), plant growth regulators such as hormones, livestock antibiotics, food additives, and genetically modified organisms.
[1]
Organic agricultural methods are internationally regulated and legally enforced by many nations, based in large part on the standards set by the International Federation of Organic Agriculture Movements (IFOAM), an international umbrella organization for organic farming organizations established in 1972. IFOAM defines the overarching goal of organic farming as:
"Organic agriculture is a production system that sustains the health of soils, ecosystems and people. It relies on ecological processes, biodiversity and cycles adapted to local conditions, rather than the use of inputs with adverse effects. Organic agriculture combines tradition, innovation and science to benefit the shared environment and promote fair relationships and a good quality of life for all involved.."
—International Federation of Organic Agriculture Movements[2]
Since 1990, the market for organic products has grown from nothing, reaching $55 billion in 2009 according to Organic Monitor (www.organicmonitor.com). This demand has driven a similar increase in organically managed farmland. Approximately 37,000,000 hectares (91,000,000 acres) worldwide are now farmed organically, representing approximately 0.9 percent of total world farmland (2009) (see Willer/Kilcher 2011).
Contents
- 1 History
- 2 Methods
- 2.1 Soil management
- 2.2 Weed management
- 2.3 Controlling other organisms
- 2.4 Genetic modification
- 3 Standards
- 4 Economics
- 4.1 Geographic producer distribution
- 4.2 Growth
- 4.3 Productivity and profitability
- 4.3.1 Profitability
- 4.3.2 Sustainability (African case)
- 4.4 Employment impact
- 5 Externalities
- 5.1 Pesticides
- 5.2 Food quality and safety
- 5.3 Clothing quality and safety
- 5.4 Soil conservation
- 5.5 Climate change
- 5.6 Nutrient leaching
- 5.7 Biodiversity
- 6 Sales and marketing
- 6.1 Distributors
- 6.2 Farmers' markets
- 7 Capacity building
- 8 Controversy
|
History
Main article: History of organic farming
The organic movement began in the 1930s and 1940s as a reaction to agriculture's growing reliance on synthetic fertilizers. Artificial fertilizers had been created during the 18th century, initially with superphosphates and then ammonia-based fertilizers mass-produced using the Haber-Bosch process developed during World War I. These early fertilizers were cheap, powerful, and easy to transport in bulk. Similar advances occurred in chemical pesticides in the 1940s, leading to the decade being referred to as the 'pesticide era'.
[3]
Sir Albert Howard is widely considered to be the father of organic farming.
[4] Further work was done by J.I. Rodale in the United States, Lady Eve Balfour in the United Kingdom, and many others across the world.
Organic farming has made up only a fraction of total agricultural output from its beginning until today. Increasing environmental awareness in the general population has transformed the originally supply-driven movement to a demand-driven one. Premium prices and some government subsidies attracted farmers. In the developing world, many producers farm according to traditional methods which are comparable to organic farming but are not certified. In other cases, farmers in the developing world have converted for economic reasons.
[5]
Methods
Main article: Organic farming methods
Organic cultivation of mixed vegetables in Capay, California. Note the hedgerow in the background.
"An organic farm, properly speaking, is not one that uses certain methods and substances and avoids others; it is a farm whose structure is formed in imitation of the structure of a natural system that has the integrity, the independence and the benign dependence of an organism"
—Wendell Berry, "The Gift of Good Land"
Soil management
Plants need nitrogen, phosphorus, and potassium, as well as micronutrients and symbiotic relationships with fungi and other organisms to flourish, but getting enough nitrogen, and particularly synchronization so that plants get enough nitrogen at the right time (when plants need it most), is likely the greatest challenge for organic farmers.
[6] Crop rotation and green manure ("cover crops") help to provide nitrogen through legumes (more precisely, the
Fabaceae family) which fix nitrogen from the atmosphere through symbiosis with rhizobial bacteria. Intercropping, which is sometimes used for insect and disease control, can also increase soil nutrients, but the competition between the legume and the crop can be problematic and wider spacing between crop rows is required. Crop residues can be ploughed back into the soil, and different plants leave different amounts of nitrogen, potentially aiding synchronization.
[6] Organic farmers also use animal manure, certain processed fertilizers such as seed meal and various mineral powders such as rock phosphate and greensand, a naturally occurring form of potash which provides potassium. Together these methods help to control erosion. In some cases pH may need to be amended. Natural pH amendments include lime and sulfur, but in the U.S. some compounds such as iron sulfate, aluminum sulfate, magnesium sulfate, and soluble boron products are allowed in organic farming.
[7]:43
Mixed farms with both livestock and crops can operate as ley farms, whereby the land gathers fertility through growing nitrogen-fixing forage grasses such as white clover or alfalfa and grows cash crops or cereals when fertility is established. Farms without livestock ("stockless") may find it more difficult to maintain fertility, and may rely more on external inputs such as imported manure as well as grain legumes and green manures, although grain legumes may fix limited nitrogen because they are harvested. Horticultural farms growing fruits and vegetables which operate in protected conditions are often even more reliant upon external inputs.
[6]
Biological research on soil and soil organisms has proven beneficial to organic farming. Varieties of bacteria and fungi break down chemicals, plant matter and animal waste into productive soil nutrients. In turn, they produce benefits of healthier yields and more productive soil for future crops.
[8] Fields with less or no manure display significantly lower yields, due to decreased soil microbe community, providing a healthier, more arable soil system.
[9]
Weed management
Organic weed management promotes weed suppression, rather than weed elimination, by enhancing crop competition and phytotoxic effects on weeds.
[10] Organic farmers integrate cultural, biological, mechanical, physical and chemical tactics to manage weeds without synthetic herbicides.
Organic standards require rotation of annual crops,
[11] meaning that a single crop cannot be grown in the same location without a different, intervening crop. Organic crop rotations frequently include weed-suppressive cover crops and crops with dissimilar life cycles to discourage weeds associated with a particular crop.
[10] Organic farmers strive to increase soil organic matter content, which can support microorganisms that destroy common weed seeds.
[12]
Other cultural practices used to enhance crop competitiveness and reduce weed pressure include selection of competitive crop varieties, high-density planting, tight row spacing, and late planting into warm soil to encourage rapid crop germination.
[10]
Mechanical and physical weed control practices used on organic farms can be broadly grouped as:
[13]
- Tillage - Turning the soil between crops to incorporate crop residues and soil amendments; remove existing weed growth and prepare a seedbed for planting;
- Cultivation - Disturbing the soil after seeding;
- Mowing and cutting - Removing top growth of weeds;
- Flame weeding and thermal weeding - Using heat to kill weeds; and
- Mulching - Blocking weed emergence with organic materials, plastic films, or landscape fabric.
Some naturally-sourced chemicals are allowed for herbicidal use. These include certain formulations of acetic acid (concentrated vinegar), corn gluten meal, and essential oils. A few selective bioherbicides based on fungal pathogens have also been developed. At this time, however, organic herbicides and bioherbicides play a minor role in the organic weed control toolbox.
[13]
Weeds can be controlled by grazing. For example, geese have been used successfully to weed a range of organic crops including cotton, strawberries, tobacco, and corn,
[14] reviving the practice of keeping cotton patch geese, common in the southern U.S. before the 1950s. Similarly, some rice farmers introduce ducks and fish to wet paddy fields to eat both weeds and insects.
[15]
Controlling other organisms
See also: Biological pest control
Organisms aside from weeds that cause problems on organic farms include arthropods (e.g. insects, mites), nematodes, fungi and bacteria. Organic farmers use a wide range of Integrated Pest Management practices to prevent pests and diseases. These include, but are not limited to, crop rotation and nutrient management; sanitation to remove pest habitat; provision of habitat for beneficial organisms; selection of pest-resistant crops and animals; crop protection using physical barriers, such as row covers; and crop diversification through companion planting or establishment of polycultures.
Organic farmers often depend on biological pest control, the use of beneficial organisms to reduce pest populations. Examples of beneficial insects include minute pirate bugs, big-eyed bugs, and to a lesser extent ladybugs (which tend to fly away), all of which eat a wide range of pests. Lacewings are also effective, but tend to fly away. Praying mantis tend to move more slowly and eat less heavily. Parasitoid wasps tend to be effective for their selected prey, but like all small insects can be less effective outdoors because the wind controls their movement. Predatory mites are effective for controlling other mites.
[7]:66-90
When these practices are insufficient to prevent or control pests an organic farmer may apply a pesticide. With some exceptions, naturally-occurring pesticides are allowed for use on organic farms, and synthetic substances are prohibited. Pesticides with different modes of action should be rotated to minimize development of pesticide resistance.
Naturally-derived insecticides allowed for use on organic farms use include
Bacillus thuringiensis (a bacterial toxin), pyrethrum (a chrysanthemum extract), spinosad (a bacterial metabolite), neem (a tree extract) and rotenone (a legume root extract). These are sometimes called green pesticides because they are generally, but not necessarily, safer and more environmentally friendly than synthetic pesticides.
[7]:92[unreliable source?] Rotenone and pyrethrum are particularly controversial because they work by attacking the nervous system, like most conventional insecticides. Fewer than 10% of organic farmers use these pesticides regularly; one survey found that only 5.3% of vegetable growers in California use rotenone while 1.7% use pyrethrum (Lotter 2003:26).
Naturally-derived fungicides allowed for use on organic farms include the bacteria
Bacillus subtilis and
Bacillus pumilus; and the fungus
Trichoderma harzianum. These are mainly effective for diseases affecting roots. Agricultural Research Service scientists have found that caprylic acid, a naturally-occurring fatty acid in milk and coconuts, as well as other natural plant extracts have antimicrobial characteristics that can help.
[16] Compost tea contains a mix of beneficial microbes, which may attack or out-compete certain plant pathogens,
[17] but variability among formulations and preparation methods may contribute to inconsistent results or even dangerous growth of toxic microbes in compost teas.
[18]
Some naturally-derived pesticides are not allowed for use on organic farms. These include nicotine sulfate, arsenic, and strychnine.
[19]
Synthetic pesticides allowed for use on organic farms include insecticidal soaps and horticultural oils for insect management; and Bordeaux mixture, copper hydroxide and sodium bicarbonate for managing fungi.
[19]
Genetic modification
Main article: Genetically modified organism
A key characteristic of organic farming is the rejection of genetically engineered plants and animals. On October 19, 1998, participants at IFOAM's 12th Scientific Conference issued the Mar del Plata Declaration, where more than 600 delegates from over 60 countries voted unanimously to exclude the use of genetically modified organisms in food production and agriculture.
Although opposition to the use of any transgenic technologies in organic farming is strong, agricultural researchers Luis Herrera-Estrella and Ariel Alvarez-Morales continue to advocate integration of transgenic technologies into organic farming as the optimal means to sustainable agriculture, particularly in the developing world.
[20] Similarly, some organic farmers question the rationale behind the ban on the use of genetically engineered seed because they see it a biological technology consistent with organic principles.
[21]
Although GMOs are excluded from organic farming, there is concern that the pollen from genetically modified crops is increasingly penetrating organic and heirloom seed stocks, making it difficult, if not impossible, to keep these genomes from entering the organic food supply. International trade restrictions limit the availability GMOs to certain countries.
[citation needed]
The dangers that genetic modification could pose to the environment and/or individual health are hotly contested.
[22]
Standards
Main article: Organic certification
Standards regulate production methods and in some cases final output for organic agriculture. Standards may be voluntary or legislated. As early as the 1970s private associations certified organic producers. In the 1980s, governments began to produce organic production guidelines. In the 1990s, a trend toward legislated standards began, most notably with the 1991 EU-Eco-regulation developed for European Union,
[23] which set standards for 12 countries, and a 1993 UK program. The EU's program was followed by a Japanese program in 2001, and in 2002 the U.S. created the National Organic Program (NOP).
[24] As of 2007 over 60 countries regulate organic farming (IFOAM 2007:11). In 2005 IFOAM created the Principles of Organic Agriculture, an international guideline for certification criteria.
[25] Typically the agencies accredit certification groups rather than individual farms.
Organic production materials used in and foods are tested independently by the Organic Materials Review Institute.
[26]
Composting
Under USDA organic standards, manure must be subjected to proper thermophilic composting and allowed to reach a sterilizing temperature. If raw animal manure is used, 120 days must pass before the crop is harvested if the final product comes into direct contact with the soil. For products which do not come into direct contact with soil, 90 days must pass prior to harvest.
[27]
Economics
The economics of organic farming, a subfield of agricultural economics, encompasses the entire process and effects of organic farming in terms of human society, including social costs, opportunity costs, unintended consequences, information asymmetries, and economies of scale. Although the scope of economics is broad, agricultural economics tends to focus on maximizing yields and efficiency at the farm level. Economics takes an anthropocentric approach to the value of the natural world: biodiversity, for example, is considered beneficial only to the extent that it is valued by people and increases profits. Some entities such as the European Union subsidize organic farming, in large part because these countries want to account for the externalities of reduced water use, reduced water contamination, reduced soil erosion, reduced carbon emissions, increased biodiversity, and assorted other benefits that result from organic farming.
[citation needed]
Traditional organic farming is labor and knowledge-intensive whereas conventional farming is capital-intensive, requiring more energy and manufactured inputs.
[28]
Organic farmers in California have cited marketing as their greatest obstacle.
[29]
Geographic producer distribution
The markets for organic products are strongest in North America and Europe, which as of 2001 are estimated to have $6 and $8 billion respectively of the $20 billion global market (Lotter 2003:6). As of 2007 Australasia has 39% of the total organic farmland, including Australia's 1,180,000 hectares (2,900,000 acres) but 97 percent of this land is sprawling rangeland (2007:35). US sales are 20x as much. (2003:7). Europe farms 23 percent of global organic farmland (6.9 million hectares), followed by Latin America with 19 percent (5.8 million hectares). Asia has 9.5 percent while North America has 7.2 percent. Africa has 3 percent.
[30]
Besides Australia, the countries with the most organic farmland are Argentina (3.1 million hectares), China (2.3 million hectares), and the United States (1.6 million hectares). Much of Argentina's organic farmland is pasture, like that of Australia (2007:42). Italy, Spain, Germany, Brazil (the world's largest agricultural exporter), Uruguay, and the UK follow the United States in the amount of organic land (2007:26).
Growth
Organic farmland by world region (2000-2008)
As of 2001, the estimated market value of certified organic products was estimated to be $20 billion. By 2002 this was $23 billion and by 2007 more than $46 billion.
[31]
In recent years both Europe (2007: 7.8 million hectares, European Union: 7.2 million hectares) and North America (2007: 2.2 million hectares) have experienced strong growth in organic farmland. In the EU it grew by 21% in the period 2005 to 2008.
[32] However, this growth has occurred under different conditions. While the European Union has shifted agricultural subsidies to organic farmers due to perceived environmental benefits, the United States has not,
[33] continuing to subsidize some but not all traditional commercial crops, such as corn and sugar. As a result of this policy difference, as of 2008 4.1% percent of European Union farmland was organically managed compared to the 0.6 percent in the U.S.
[31]
IFOAM's most recent edition of
The World of Organic Agriculture: Statistics and Emerging Trends 2009 lists the countries which had the most hectares in 2007. The country with the most organic land is Australia with more than 12 million hectares, followed by Argentina, Brazil and the US. In total 32.2 million hectares were under organic management in 2007. For 1999 11 million hectares of organically managed land are reported.
[31]
As organic farming becomes a major commercial force in agriculture, it is likely to gain increasing impact on national agricultural policies and confront some of the scaling challenges faced by conventional agriculture.
[34]
Productivity and profitability
Various studies find that versus conventional agriculture, organic crops yielded 91%,
[35] or 95-100%,
[36] along with 50% lower expenditure on fertilizer and energy, and 97% less pesticides,
[37] or 100% for corn and soybean, consuming less energy and zero pesticides.
[clarification needed] The results were attributed to lower yields in average and good years but higher yields during drought years.
[38]
A 2007 study
[39] compiling research from 293 different comparisons into a single study to assess the overall efficiency of the two agricultural systems has concluded that
...organic methods could produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without increasing the agricultural land base. (from the abstract)
Converted organic farms have lower pre-harvest yields than their conventional counterparts in developed countries (92%) but higher than their low-intensity counterparts in developing countries (132%). This is due to relatively lower adoption of fertilizers and pesticides in the developing world compared to the intensive farming of the developed world.
[40]
Organic farms withstand severe weather conditions better than conventional farms, sometimes yielding 70-90% more than conventional farms during droughts.
[41] Organic farms are more profitable in the drier states of the United States, likely due to their superior drought performance.
[42] Organic farms survive hurricane damage much better, retaining 20 to 40% more topsoil and smaller economic losses at highly significant levels than their neighbors.
[43]
Contrary to widespread belief, organic farming can build up soil organic matter better than conventional no-till farming, which suggests long-term yield benefits from organic farming.
[44] An 18-year study of organic methods on nutrient-depleted soil, concluded that conventional methods were superior for soil fertility and yield in a cold-temperate climate, arguing that much of the benefits from organic farming are derived from imported materials which could not be regarded as "self-sustaining".
[45]
Profitability
The decreased cost of synthetic fertilizer and pesticide inputs, along with the higher prices that consumers pay for organic produce, contribute to increased profits. Organic farms have been consistently found to be as or more profitable than conventional farms. Without the price premium, profitability is mixed.
[46] Organic production was more profitable in Wisconsin, given price premiums.
[47]
Sustainability (African case)
In 2008 the UN Environmental Programme (UNEP) and UN Conference on Trade and Development (UNCTAD) stated that "organic agriculture can be more conducive to food security in Africa than most conventional production systems, and that it is more likely to be sustainable in the long-term"
[48] and that "yields had more than doubled where organic, or near-organic practices had been used" and that soil fertility and drought resistance improved.
[49]
Employment impact
Organic methods often require more labor than traditional farming, therefore it provides rural jobs,
[50]
Externalities
Main article: Motivations for organic agriculture
Agriculture imposes negative externalities (uncompensated costs) upon society through land and other resource use, biodiversity loss, erosion, pesticides, nutrient runoff, water usage, subsidy payments and assorted other problems. Positive externalities include self-reliance, entrepreneurship, respect for nature, and air quality. Organic methods reduce some of these costs.
[51] In 2000 uncompensated costs for 1996 reached 2,343 million British pounds or 208 pounds per hectare.
[52] In 2005 in the USA concluded that cropland costs the economy approximately 5 to 16 billion dollars ($30 to $96 per hectare), while livestock production costs 714 million dollars.
[53] Both studies recommended reducing externalities. The 2000 review included reported pesticide poisonings but did not include speculative chronic health effects of pesticides, and the 2004 review relied on a 1992 estimate of the total impact of pesticides.
It has been proposed that organic agriculture can reduce the level of some negative externalities from (conventional) agriculture. Whether the benefits are private or public depends upon the division of property rights.
[54]
Pesticides
A sign outside of an organic apple orchard in Pateros, Washington reminding orchardists not to spray pesticides on these trees.
Most organic farms largely avoid pesticides as opposed to conventional farms.
[55] Some pesticides damage the environment or with direct exposure, human health. The five main pesticides used in organic farming are Bt (a bacterial toxin), pyrethrum, rotenone,
[56] copper and sulphur.
[57] Fewer than 10% of organic vegetable farmers acknowledge using these pesticides regularly
[citation needed]; 5.3% of vegetable growers will admit rotenone use; while 1.7% admit pyrethrum use(Lotter 2003:26). Reduction and elimination of chemical pesticide use is technically challenging.
[58] Organic pesticides often complement other pest control strategies.
Ecological concerns primarily focus around pesticide use, as 16% of the world's pesticides are used in the production of cotton .
[59]
Runoff is one of the most damaging effects of pesticide use. The USDA Natural Resources Conservation Service tracks the environmental effects of water contamination and concluded, "the Nation's pesticide policies during the last twenty six years have succeeded in reducing overall environmental risk, in spite of slight increases in area planted and weight of pesticides applied. Nevertheless, there are still areas of the country where there is no evidence of progress, and areas where risk levels for protection of drinking water, fish, algae and crustaceans remain high".
[60]
[61]
Food quality and safety
Main article: Organic food
Many studies have examined the relative quality and safety benefits of organic and conventional agricultural techniques. The results are diverse. Some find no significant differences. Others disagree. An example of the "no differences" school stated:
No evidence of a difference in content of nutrients and other substances between organically and conventionally produced crops and livestock products was detected for the majority of nutrients assessed in this review suggesting that organically and conventionally produced crops and livestock products are broadly comparable in their nutrient content... There is no good evidence that increased dietary intake, of the nutrients identified in this review to be present in larger amounts in organically than in conventionally produced crops and livestock products, would be of benefit to individuals consuming a normal varied diet, and it is therefore unlikely that these differences in nutrient content are relevant to consumer health.[62]
However, they also found that statistically significant differences between the composition of organic and conventional food were present for a few substances.
[citation needed]
"Organic products stand out as having higher levels of secondary plant compounds and vitamin C".
[63] The fatty acid profile of organic milk and meat is often nutritionally superior.
[citation needed] Organic carbohydrates and minerals are not different from conventional products.
[citation needed] Organic foods have more nutritional value.
[64] Organic produce has double the flavonoids, an important antioxidant.
[65] Organic kiwifruit had more antioxidants.
[66]
A review of potential health effects analysed eleven articles, concluding, "because of the limited and highly variable data available, and concerns over the reliability of some reported findings, there is currently no evidence of a health benefit from consuming orga nic compared to conventionally produced foodstuffs. It should be noted that this conclusion relates to the evidence base currently available on the nutrient content of foodstuffs, which contains limitations in the design and in the comparability of studies."
[67]
Individual studies have considered a variety of possible impacts, including pesticide residues.
[68] Pesticide residues present a second channel for health effects.
[69][70] Comments include, "Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives; yet, "the significance of this difference is questionable"
[68] and "It is intuitive to assume that children whose diets consist of organic food items would have a lower probability of neurologic health risks", and pesticide exposure brought an increased risk for ADHD in one study.
Nitrate concentrations may be less, but the health impact of nitrates is debated.
[citation needed] Lack of data has limited research on the health effects of natural plant pesticides and bacterial pathogens.
[68] Consumption of organic milk was associated with a decrease in risk for eczema, although no comparable benefit was found for organic fruits, vegetables, or meat.
[71]
The higher cost of organic food (ranging from 45 to 200%) could inhibit consumption of the recommended 5 servings per day of vegetables and fruits, which improve health and reduce cancer regardless of their source.
[68]
Clothing quality and safety
Main article: Organic clothing
Recently, organic clothing has become widely available. Although many consumers of organic clothing merely dislike synthetic chemicals, a significant portion of the organic clothing market comes from those suffering from Multiple Chemical Sensitivity, a chronic medical condition characterized by symptoms that the affected person says are adverse effects from exposure to low levels of chemicals.
[citation needed]
Soil conservation
Main article: Soil conservation
In
Dirt: The Erosion of Civilizations, geomorphologist David Montgomery outlines a coming crisis from soil erosion. Agriculture relies on roughly one meter of topsoil, and that is being depleted ten times faster than it is being replaced.
[72] No-till farming, which some claim depends upon pesticides, is one way to minimize erosion. However, a recent study by the USDA's Agricultural Research Service has found that manure applications in tilled organic farming are better at building up the soil than no-till.
[73][74][75]
Climate change
Organic agriculture emphasizes closed nutrient cycles, biodiversity, and effective soil management providing the capacity to mitigate and even reverse the effects of climate change.
[76] Organic agriculture decreases fossil fuel emissions and sequesters carbon in the soil. The elimination of synthetic nitrogen in organic systems decreases fossil fuel consumption by 33 percent and carbon sequestration takes
CO2 out of the atmosphere by putting it in the soil in the form of organic matter which is often lost in conventionally managed soils. Carbon sequestration occurs at especially high levels in organic no-till managed soil.
[74]
Agriculture has been undervalued and underestimated as a means to combat global climate change. Soil carbon data show that regenerative organic agricultural practices are among the most effective strategies for mitigating
CO2emissions.
[74]
Nutrient leaching
Excess nutrients in lakes, rivers, and groundwater can cause algal blooms, eutrophication, and subsequent dead zones. In addition, nitrates are harmful to aquatic organisms by themselves. The main contributor to this pollution is nitrate fertilizers whose use is expected to "double or almost triple by 2050".
[77] Organically fertilizing fields "significantly [reduces] harmful nitrate leaching" over conventionally fertilized fields: "annual nitrate leaching was 4.4-5.6 times higher in conventional plots than organic plots".
[78]
The large dead zone in the Gulf of Mexico is caused in large part by agricultural runoff: a combination of fertilizer and livestock manure. Over half of the nitrogen released into the Gulf comes from agriculture. This increases costs for fishermen, as they must travel far from the coast to find fish.
[79]
Nitrogen leaching into the Danube River was substantially lower among organic farms. The resulting externalities could be neutralized by charging 1 euro per kg of released nitrogen.
[80]
Agricultural runoff and algae blooms are strongly linked in California.
[81]
Biodiversity
Main article: Organic farming and biodiversity
A wide range of organisms benefit from organic farming, but it is unclear whether organic methods confer greater benefits than conventional integrated agri-environmental programs.
[82] Nearly all non-crop, naturally occurring species observed in comparative farm land practice studies show a preference for organic farming both by abundance and diversity.
[82][83] An average of 30% more species inhabit organic farms.
[84] Birds, butterflies, soil microbes, beetles, earthworms,
[85] spiders, vegetation, and mammals are particularly affected. Lack of herbicides and pesticides improve biodiversity fitness and population density.
[83] Many weed species attract beneficial insects that improve soil qualities and forage on weed pests.
[86] Soil-bound organisms often benefit because of increased bacteria populations due to natural fertilizer such as manure, while experiencing reduced intake of herbicides and pesticides.
[82] Increased biodiversity, especially from beneficial soil microbes and mycorrhizae have been proposed as an explanation for the high yields experienced by some organic plots, especially in light of the differences seen in a 21-year comparison of organic and control fields.
[9]
Biodiversity from organic farming provides capital to humans. Species found in organic farms enhance sustainability by reducing human input (e.g. fertilizers, pesticides).
[87] Farmers that produce with organic methods reduce risk of poor yields by promoting biodiversity.
[citation needed] Common game birds such as the ring-necked pheasant and the northern bobwhite often reside in agriculture landscapes, and benefit recreational hunters.
[citation needed]
Sales and marketing
Most sales are concentrated in developed nations. These products are what economists call credence goods in that they rely on uncertain certification. Interest in organic products dropped between 2006 and 2008, and 42% of Americans polled don't trust organic produce.
[88] 69% of Americans claim to occasionally buy organic products, down from 73% in 2005. One theory was that consumers were substituting "local" produce for "organic" produce.
[89]
Distributors
In the United States, 75% of organic farms are smaller than 2.5 hectares. In California 2% of the farms account for over half of sales.(Lotter 2003:4) Small farms join together in cooperatives such as Organic Valley, Inc. to market their goods more effectively.
Over twenty-five, most cooperative distributors merged or were acquired by large multinationals such as General Mills, Heinz, ConAgra, Kellogg, and others. In 1982 there were 28 consumer cooperative distributors, but as of 2007 only 3 remained.
[90] This consolidation has raised concerns among consumers and journalists of potential fraud and degradation in standards. Most sell their organic products through subsidiaries, under other labels.
[91]
Farmers' markets
Price premiums are important for the profitability of small organic farmers. Farmers selling directly to consumers at farmers' markets have continued to achieve these higher returns. In the United States the number of farmers' markets tripled from 1,755 in 1994 to 5,274 in 2009.
[92]
Capacity building
Organic agriculture can contribute to ecologically sustainable, socio-economic development, especially in poorer countries.
[93] The application of organic principles enables employment of local resources (e.g. local seed varieties, manure, etc.) and therefore cost-effectiveness. Local and international markets for organic products show tremendous growth prospects and offer creative producers and exporters excellent opportunities to improve their income and living conditions.
[citation needed]
Organic agriculture is knowledge intensive. Globally, capacity building efforts are underway, including localized training material, to limited effect. As of 2007, the International Federation of Organic Agriculture Movements hosted more than 170 free manuals and 75 training opportunities online.
[citation needed]
Controversy
Norman Borlaug, father of the "Green Revolution", Nobel Peace Prize laureate, Prof A. Trewavas and other critics contested the notion that organic agricultural systems are more friendly to the environment and more sustainable than conventional farming systems. Borlaug asserts that organic farming practices can at most feed 4 billion people, after expanding cropland dramatically and destroying ecosystems in the process.
[94][95][96] The Danish Environmental Protection Agency estimated that phasing out all pesticides would result in an overall yield reduction of about 25%. Environmental and health effects were assumed but hard to assess.
[97]
In contrast, the UN Environmental Programme concluded that organic methods greatly increase yields in Africa.
[48] A review of over two hundred crop comparisons argued that organic farming could produce enough food to sustain the current human population and that the difference in yields between organic and non-organic methods were small, with non-organic methods yielding slightly more in developed areas and organic methods yielding slightly more in developing areas.
[40]
That analysis has been criticised by Alex Avery of the Hudson Institute, who contends that the review claimed many non-organic studies to be organic, misreported organic yields, made false comparisons between yields of organic and non-organic studies which were not comparable, counted high organic yields several times by citing different papers which referenced the same data, and gave equal weight to studies from sources which were not impartial.
[98] The Center for Disease Control repudiated a claim by Avery's father, Dennis Avery (also at Hudson) that the risk of E. coli infection was eight times higher when eating organic food. (Avery had cited CDC as a source.) Avery had included problems stemming from non-organic unpasteurized juice in his calculations.
[99][100][101]
Urs Niggli, director of the FiBL Institute contends that there is
[102] a global campaign against organic farming that mostly derives from Avery's book
The truth about organic farming.
[99]
