Organic farming

Organic farming is a form of agriculture that relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and synthetic pesticides, plant growth regulators, livestock feed additives, and genetically modified organisms.[citation needed]

Since 1990 the market for organic products has grown at a rapid pace, averaging 20-25 percent per year to reach $33 billion in 2005. This demand has driven a similar increase in organically managed farmland. Approximately 306,000 square kilometres (30.6 million hectares) worldwide are now farmed organically, representing approximately 2% of total world farmland.[3] In addition, as of 2005 organic wild products are farmed on approximately 62 million hectares (IFOAM 2007:10).

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, an international umbrella organization for organic organizations established in 1972. The overarching goal of organic farming is defined as follows:

"The role of organic agriculture, whether in farming, processing, distribution, or consumption, is to sustain and enhance the health of ecosystems and organisms from the smallest in the soil to human beings."



Geography

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 market (2003:6). However, as of 2007 organic farmland is distributed across the globe. Australasia has 39% of the total organic farmland with Australia's 11.8 million hectares, but 97 percent of this land is sprawling rangeland (2007:35), which results in total sales of approximately 5% of US sales (2003:7). Europe has 23 percent of total 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 a mere 3 percent.

Besides Australia, the countries with the most organic area 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 Australia (2007:42). Italy, Spain, Germany, Brazil, Uruguay, and the UK follow the United States by the amount of land managed organically (2007:26).



Growth
As of 2001, the estimated total market value of certified organic products was estimated to be $20 billion. By 2002 this was $23 billion and by 2005 $33 billion, with Organic Monitor projecting sales of $40 billion in 2006 (IFOAM 2007:11). The change from 2001 to 2005 represents a compound growth of 10.6 percent.

In recent years both Europe and North America have experienced strong growth in organic farmland. Each added half a million hectares from 2004 to 2007 -- for the US this is a 29 percent change (IFOAM 2007:11,27). However, this growth has occurred under different conditions. While the European Union has shifted agricultural subsidies to organic farmers in recognition of its environmental benefits, the United States has taken a free market approach[1]. As a result, as of 2001 3 percent of European farmland was organically managed compared to just .3 percent of United States farmland (Lotter 2003:7). By 2005 Europe's organic land was 3.9 percent while the United States' had risen to 0.6 percent (IFOAM 2007:14-15).

IFOAM's The World of Organic Agriculture: Statistics and Emerging Trends 2007 lists the countries which added the most hectares and had the highest percentage growth in 2007 (IFOAM 2007:27-28). Among these, China is listed third in adding the most hectares behind the United States and Argentina. China jumped from approximately 300,000 hectares of organic land in 2005 to approximately 3.5 million hectares in 2006 -- an increase of over a thousand percent.[2] This rise can be attributed to the certification of China's Organic Food Development Center in 2002 by IFOAM. The end of 2005 marks the end of the three-year transition period begun in 2002.




History
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 derived 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. The 1940s has been referred to as the 'pesticide era'. Sir Albert Howard is widely considered to be the father of organic farming.[4] Rudolf Steiner , a German philosopher, made important strides in the earliest organic theory with his biodynamic agriculture. More work was done by J.I. Rodale in the United States, Lady Eve Balfour in the United Kingdom, and many others across the world.

As a percentage of total agricultural output, organic farming has remained tiny since its beginning. As environmental awareness and concern increased, the originally supply-driven movement became demand-driven. Standardized certification brought premium prices, and in some cases government subsidies attracted many farmers into converting. In the developing world, many farmers farm according to traditional methods but are not certified. In other cases, farmers in the developing world have converted out of necessity. As a proportion of total global agricultural output, organic output remains small, but it has been growing rapidly in many countries, notably in Europe.



Methods

"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"
The term holistic is often used to describe organic farming [5], Enhancing soil health is the cornerstone of organic farming [6]. A variety of methods are employed, including crop rotation, green manure, cover cropping, application of compost, and mulching. Organic farmers also use certain processed fertilizers such as seed meal, and various mineral powders such as rock phosphate and greensand, a naturally occurring form of potash. These methods help to control erosion, promote biodiversity, and enhance the health of the soil.

Pest control targets animal pests (including insects), fungi, weeds and disease. Organic pest control involves the cumulative effect of many techniques, including, allowing for an acceptable level of pest damage, encouraging or even introducing beneficial organisms, careful crop selection and crop rotation, and mechanical controls such as row covers and traps. These techniques generally provide benefits in addition to pest control—soil protection and improvement, fertilization, pollination, water conservation, season extension, etc.—and these benefits are both complementary and cumulative in overall effect on farm health . Effective organic pest control requires a thorough understanding of pest life cycles and interactions.

Weeds are controlled mechanically, thermically and through the use of covercrops and mulches.



Standards
Organic farming is distinguished by formal standards regulating production methods, and in some cases, final output. Standards may be voluntary or legislated. As early as the 1970s, private associations created standards, against which organic producers could voluntarily have themselves certified. In the 1980s, governments began to produce organic production guidelines. Beginning in the 1990s, a trend toward legislation of standards began, most notably the EU-Eco-regulation developed in the European Union. As of 2007 over 60 countries have regulations on organic farming (IFOAM 2007:11).

Organic Agriculture also is the only government enforced humane laws, such as limited to de-beaking on chickens, guarantee to pasture time to cows, and more humane ways to deal with bees.

In 1991, the European Commission formulated the first government system to regulate organic labeling. setting the rules for 12 countries.[3] Organic certification became mandatory and was also required for organic imports. The mandatory certification solidified consumer trust in organic products.

The international framework for organic farming is provided by IFOAM. For IFOAM members, organic agriculture is based upon the Principles of Organic Agriculture and the IFOAM Norms.[4] The IFOAM Norms consist of the IFOAM Basic Standards and IFOAM Accreditation Criteria.

The IFOAM Basic Standards are a set of "standards for standards." They are established through a democratic and international process and reflect the current state of the art for organic production and processing. They are best seen as a work in progress to lead the continued development of organic practices worldwide. They provide a framework for national and regional standard-setting and certification bodies to develop detailed certification standards that are responsive to local conditions.

Legislated standards are established at the national level, and vary from country to country. In recent years, many countries have legislated organic production, including the EU nations (1990s), Japan (2001), and the US (2002). Non-governmental national and international associations also have their own production standards. In countries where production is regulated, these agencies must be accredited by the government.

Since 1993 when EU Council Regulation 2092/91 became effective, organic food production has been strictly regulated in the UK.

In India, standards for organic agriculture were announced in May 2001, and the National Programme on Organic Production (NPOP) is administered under the Ministry of Commerce.

In 2002, the United States Department of Agriculture (USDA) established production standards, under the National Organic Program (NOP), which regulate the commercial use of the term organic.[5] Farmers and food processors must comply with the NOP in order to use the word.



Composting
Under USDA organic standards, manure must be composted and allowed to reach a sterilizing temperature. If raw animal manure is used, 120 days must pass before the crop is harvested.[6]



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. Mainstream 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 governments such as the European Union subsidize organic farming, in large part because these countries believe in the external benefits of reduced water use, reduced water contamination by pesticides and nutrients of organic farming, reduced soil erosion, reduced carbon emissions, increased biodiversity, and assorted other benefits.

Organic farming is labor and knowledge-intensive whereas conventional farming is capital-intensive, requiring more energy and manufactured inputs. Organic farmers in California have cited marketing as their greatest obstacle.[7]




Productivity and Profitability
A 2006 study suggests that converted organic farms have lower pre-harvest yields than their conventional counterparts in developed countries (92%) and that organic farms have higher pre-harvest yields than their low-intensity counterparts in developing countries (132%). The researcher attributes this to a relative lack of expensive fertilizers and pesticides in the developing world compared to the intensive, subsidy-driven farming of the developed world. Nonetheless, the researcher purposely avoids making the claim that organic methods routinely outperform green-revolution (conventional) methods.[8] This study incorporated a 1990 review of 205 crop comparisons which found that organic crops had 91% of conventional yields.[9] A major US survey published in 2001, analyzed results from 150 growing seasons for various crops and concluded that organic yields were 95-100% of conventional yields.[10]

Lotter (2003:10) reports that repeated studies have found that organic farms withstand severe weather conditions better than conventional farms, sometimes yielding 70-90% more than conventional farms during droughts. A 22-year farm trial study by Cornell University published in 2005 concluded that organic farming produces the same corn and soybean yields as conventional methods over the long-term averages, but consumed less energy and used zero pesticides. The results were attributed to lower yields in general but higher yields during drought years.[11] A study of 1,804 organic farms in Central American hit by Hurricane Mitch in 1998 found that the organic farms sustained the damage much better, retaining 20 to 40% more topsoil and smaller economic losses at highly significant levels than their neighbors.[12]

On the other hand, a prominent 21-year Swiss study found an average of 20% lower organic yields over conventional, along with 50% lower expenditure on fertilizer and energy, and 97% less pesticides.[13] A long-term study by U.S Department of Agriculture Agricultural Research Service (ARS) scientists concluded that, 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. [14]

While organic farms have lower yields, organic methods require no synthetic fertilizer and pesticides. The decreased cost on those inputs, along with the premiums which consumers pay for organic produce, create higher profits for organic farmers. Organic farms have been consistently found to be as or more profitable than conventional farms with premiums included, but without premiums profitability is mixed (Lotter 2003:11). Welsh (1999) reports that organic farmers are more profitable in the drier states of the United States, likely due to their superior drought performance.[15]



Macroeconomic Impact
Organic methods often require more labor,[16] providing rural jobs but increasing costs to urban consumers.


Externalities
Agriculture in general imposes external costs upon society through pesticides, nutrient runoff, excessive water usage, and assorted other problems. As organic methods minimize some of these factors, organic farming is believed to impose fewer external costs upon society.


Pesticides
Due to the increased concern for the risk to human health, as well as the recent and ongoing development of pesticide resistance, need to reduce use of pesticides is well recognised but implementation for reduction and elimination of pesticide is technologically very difficult. [7] Most organic farm products use reduced pesticide claim but very few manage to eliminate the use of pesticide entirely.

While organic farming can, with extra cost, easily substitute chemical fertilizer with organic one, finding an alternative method for eliminating weeds as well as insects which feast on crops is difficult. Pest resistant GM crops are an alternative to pesticide use, but one which is unacceptable to the organic farming movement. [8]

One natural method to control pests is to introduce a natural predator in place of the pesticide, though this approach has various control issues. Another method is crop rotation, which restricts expansion of the insect population. For weed elimination, the traditional method is to remove weeds by hand, which is still practiced in developing countries by small scale farmers. However, this has proven too costly in developed countries where labor is more expensive. One recent innovation in rice farming is to introduce ducks and fish to wet paddy fields, which eat both weeds and insects.[9]



Health Risks
Organic farms use few pesticides, although they are allowed to use some natural ones. The main three are Bt, pyrethrum and rotenone. However, surveys have found that 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). Nevertheless, rotenone has been linked to Parkinson's in rats and can be considered toxic to humans (Lotter 2003:26).

On the other hand, conventional farming uses large quantities of pesticides through techniques such as crop dusting. Studies have shown that people who work with pesticides have an increased risk of developing Parkinson's disease.[17][18] The pesticides examined in these two long-term studies, paraquat and dieldrin, are not allowed on organic farms. The herbicide paraquat and fungicide maneb together, but not alone, have been shown to cause brain damage in mice.[19]

Around 31,000 tonnes of pesticides are used in the UK every year, and 40% of fruit, vegetables, and bread sampled in the UK were found to have pesticide residues in 2004.[20]



Children's health
Some parents are concerned about the potential neurological health risks posed to children by trace pesticide residues in food. A 2001 study demonstrated that children fed organic diets experienced significantly lower organophosphorus pesticide exposure than children fed conventional diets.[21] A similar study in 2006 measured the levels of organophosphorus pesticide exposure in 23 preschool children before and after replacing their diet with organic food: levels of organophosphorus pesticide exposure dropped dramatically and immediately when the children switched to an organic diet.[22] Although the researchers did not collect health outcome data in this study, they concluded "it is intuitive to assume that children whose diets consist of organic food items would have a lower probability of neurologic health risks."



Runoff
Pesticide runoff is one of the most significant effects of pesticide use. The USDA Natural Resources Conservation Service tracks the environmental risk posed by pesticide water contamination from farms, and its conclusion has been that "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".[23]



Genetically modified organisms
A key characteristic of organic farming is rejection of genetically engineered products, including plants and animals. On October 19, 1998, participants at IFOAM's 12th Scientific Conference of IFOAM) 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. From this point, it became widely recognized that GMOs are categorically excluded from organic farming.

Despite this vehement opposition to use of any transgenic technologies in organic farming, agricultural researchers such as Luis Herrera-Estrella & 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.[24] 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 [25]

Although GMOs are excluded from use in organic farming, there is concern that the pollen from genetically modified crops is increasingly contaminating organic and heirloom genetics making it difficult, if not impossible, to keep these genetics from entering the organic food supply. International trade restrictions limit the availability GMOs to certain countries.

The actual dangers that genetic modification could pose to the environment or, supposedly, individual health, are hotly contended. See GM food controversy.



Food quality
Healthy soils equals healthy food equals healthy people is a basic tenet of many organic farming systems.

There is extensive scientific research being carried out in Switzerland at over 200 farms to determine differences in the quality of organic food products compared to conventional in addition to other tests. The FiBL scientific research institute states that "organic products stand out as having higher levels of secondary plant compounds and vitamin C. In the case of milk and meat, the fatty acid profile is often better from a nutritional point of view. As far as carbohydrates and minerals, organic products are no different from conventional products. However, in regard to undesirables such as nitrate and pesticide residues, organic products have a clear advantage.[26] A recent study found that organically grown produce has double the flavonoids, an important antioxidant.[27]. A 2007 study found that organically grown kiwi fruits had more antioxidants than conventional kiwi.[28]

A study which isolated clear health benefits from eating organic foods was published in 2007.[29]




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.[30] No-till farming, which some claim depends upon pesticides, is regarded as one way to minimize erosion. However, a recent study by the USDA's Agricultural Research Service has found that organic farming is even better at building up the soil than no-till.[31]


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".[32] Researchers at the United States National Academy of Sciences found that that 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".[33]

Scientists believe that the large dead zone in the Gulf of Mexico is caused in large part by agricultural pollution: a combination of fertilizer runoff and livestock manure runoff. A study by the United States Geological Survey (USGS) found that over half of the nitrogen released into the Gulf comes from agriculture. The economic cost of this for fishermen may be large, as they must travel far from the coast to find fish.[34]

At the 2000 IFOAM Conference, researchers presented a study of nitrogen leaching into the Danube River. They found that nitrogen runoff was substantially lower among organic farms and suggested that the external cost could be internalized by charging 1 euro per kg of nitrogen released.[35]

A 2005 study published in Nature found a strong link between agricultural runoff and algae blooms in California.[36]



Sales and Marketing
Organic farmers report that marketing and distribution are difficult obstacles. Most of organic sales are concentrated in developed nations. These products are what economists call credence goods in that they rely on uncertain certification. As food prices rise, organic products may experience falling demand. A 2008 survey by WSL Strategic Retail found that interest in organic products had dropped since 2006, and that 42% of Americans polled don't trust organic produce. and The Hartman Group reports that 69% of Americans claim to occasionally organic products, down from 73% in 2005. The Hartman Group says that people may be substituting local produce for organic produce.[37]




Distributors
In the United States, 75% of organic farms are smaller than 2.5 hectares and in California 2% of the farms account for over half of the sales (Lotter 2003:4). Groups of small farms join together in cooperatives such as Organic Valley, Inc. to market their goods more effectively.

Over the past twenty years, however, most of these cooperative distributors have merged or been bought out. Rural sociologist Philip H. Howard has researched the structure and transformation of the organic industry in the United States. He claims that in 1982 there were 28 consumer cooperative distributors but as of 2007 there are only 3, and he has created a graphic displaying the consolidation.[38] His research shows that most of these small cooperatives have been absorbed into large multinational corporations such as General Mills, Heinz, ConAgra, Kellog, and assorted other brands. This consolidation has raised concerns among consumers and journalists of potential fraud and degradation in standards. Most of these large corporations sell their organic products through subsidiaries, allowing them to keep their names off the labels.[39]



Farmers' Markets
Price premiums are important for the profitability of small organic farmers, and so many sell directly to consumers in farmers' markets. In the United States the number of farmers' markets has grown from 1,755 in 1994 to 4,385 in 2006.[40]




Organic livestock farming
Organic farming practices may also be applied to livestock farms. Conventional livestock farms inject their animals with hormones and antibiotics,[citation needed] and keep many animals confined in small spaces,[citation needed] which may lead to the spread of disease such as Mad Cow Disease or the Avian Flu. These closely confined animals create huge amounts of waste, which can, in some cases, overflow and seep into the surrounding environment. Organic livestock farms, on the other hand, allow animals to roam freely in wide fields,[citation needed] and their grazing is rotated between fields to prevent soil erosion.[citation needed]

While organic livestock farming often requires more space and is used on a smaller scale than conventional livestock farming, many organic farmers save on feed and veterinary bills because their animals can graze naturally and do not suffer from antibiotic resistance. Research indicates that antibiotic-rich products from conventional livestock farms may be a major cause of antibiotic resistance in humans,[citation needed] an issue that has gradually become a major public health issue.[citation needed] The living standards for animals on organic farms drastically decrease the need for antibiotic use on livestock.[41][42]




Capacity building
Organic agriculture can contribute to meaningful socio-economic and ecologically sustainable development, especially in poorer countries [43]. On one hand, this is due to the application of organic principles, which means efficient management of local resources (e.g. local seed varieties, manure, etc.) and therefore cost-effectiveness. On the other hand, the market for organic products – at local and international level – has tremendous growth prospects and offers creative producers and exporters in the South excellent opportunities to improve their income and living conditions.

Organic Agriculture is a very knowledge intensive production system [44]. Therefore capacity building efforts play a central role in this regard. There are many efforts all around the world regarding the development of training material and the organization of training courses related to Organic Agriculture. Big parts of existing knowledge is still scattered and not easy accessible. Especially in Developing Countries this situation remains an important constraint for the growth of the organic sector.

For that reason, the International Federation of Organic Agriculture Movements created an Internet Training Platform [10] whose objective is to become the global reference point for Organic Agriculture training through free access to high quality training materials and training programs on Organic Agriculture. In November 2007, the Training Platform hosted more than 170 free manuals and 75 training opportunities.




Organic farming and associated biodiversity
Organic farming vs. conventional practices
In ancient farming practices, farmers did not possess the technology or manpower to have a significant impact on the destruction of biodiversity even as mass-production agriculture was rising. Nowadays, common farming methods generally rely on pesticides to maintain high yields. With such, most agricultural landscapes favor mono-culture crops with very little flora or fauna co-existence (van Elsen 2000). Modern organic farm practices such as the removal of pesticides and the inclusion of animal manure, crop rotation, and multi-cultural crops provides the chance for biodiversity to thrive.[45]


Benefits to biodiversity
Nearly all non-crop, naturally-occurring species observed in comparative farm land practice studies show a preference in organic farming both by population and richness.[46][47] Spanning all associated species, there is an average of 30% more on organic farms versus conventional farming methods.[48] Birds, butterflies, soil microbes, beetles, earthworms, spiders, vegetation, and mammals are particularly effected. Organic crops use little or no herbicides and pesticides and thus biodiversity fitness and population density benefit.[49] Many weed species attract beneficial insects that improve soil qualities and forage on weed pests.[50] Soil-bound organisms often benefit because of increased bacteria populations due to natural fertilizer spread such as manure, while experiencing reduced intake of herbicides and pesticides commonly associated with conventional farming methods.[51] Increased biodiversity, especially from soil microbes such as mycorhizzae, 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.[52]



Detriments to biodiversity through organic farming
Organic farming practices still require active participation from the farmer to effectively boost biodiversity. Making a switch to organic farming methods does not automatically or guarantee improved biodiversity. Pro-conservation ethics are required to create arable farm land that generates biodiversity. Conservationist ideals are commonly overlooked because they require additional physical and economical efforts from the producer.[53] Common weed-removal processes like undercutting and controlled burning provides little opportunity for species survival, and often leads to comparable populations and richness to conventionally-managed landscapes when performed in excess. Another common process is the addition of biotopes in the form of hedgerows and ponds to further improve species richness. Farmers commonly make the mistake of over-using these resources for more intense crop production because organic yields are typically lower. Another error comes from the over-stratification of biotopes. A series of small clusters does not provide adequate land area for high biodiversity potential.[54]



Impact of increased biodiversity
The level of biodiversity that can be yielded from organic farming provides a natural capital to humans. Species found in most organic farms provides a means of agricultural sustainability by reducing amount of human input (e.g. fertilizers, pesticides) [55] . Farmers that produce with organic methods reduce risk of poor yields by promoting biodiversity. Common game birds such as the ring-necked pheasant and the northern bobwhite often reside in agriculture landscapes, and are a natural capital yielded from high demands of recreational hunting. Because bird species richness and population are typically higher on organic farm systems, promoting biodiversity can be seen as logical and economical.



Farmers’ Benefits from Increased Biodiversity
Biological research on soil and soil organisms has proven beneficial to the system of organic farming. Varieties of bacteria and fungi break down chemicals, plant matter and animal waste into productive soil nutrients. In turn, the producer benefits by healthier yields and more arable soil for future crops.[56] Furthermore, a 21-year study was conducted testing the effects of organic soil matter and its relationship to soil quality and yield. Controls included actively managed soil with varying levels of manure, compared to a plot with no manure input. After the study commenced, there was significantly lower yields on the on the control plot when compared to the fields with manure. The concluded reason was an increased soil microbe community in the manure fields, providing a healthier, more arable soil system.[57]




Controversy
There are contentions that organic farming is unsustainable. One study from the Danish Environmental Protection Agency found that, area-for-area, organic farms of potatoes, sugar beet and seed grass produce as little as half the output of conventional farming.[58] Findings like these, and the dependence of organic food on manure from low-yield cattle, has prompted criticism from many scientists that organic farming is environmentally unsound and incapable of feeding the world population.[59] Among these critics are Norman Borlaug, father of the "green revolution," and winner of the Nobel Peace Prize, who asserts that organic farming practices can at most feed 4 billion people, after expanding cropland dramatically and destroying ecosystems in the process. [60] Yet, organic agriculture can reduce the level of negative externalities from (conventional) agriculture. Whether this is seen as private or public benefits depends upon the initial specification of property rights.[61]

One study published in Renewable Agriculture and Food Systems argues that organic farming could produce enough food per capita to sustain the current human population; the difference in yields between organic and non-organic methods were small, with non-organic methods resulting in slightly higher yields in developed areas and organic methods resulting in slightly higher yields in developing areas.[8]

In 1998, Dennis Avery of the Hudson Institute claimed the risk of E. coli infection was eight times higher when eating organic food rather than non-organic food, using the Center for Disease Control (CDC) as a source. When the CDC was contacted, it stated that there was no evidence for the claim.[62][63] The New York Times commented on Avery's attacks: "The attack on organic food by a well-financed research organization suggests that, though organic food accounts for only 1 percent of food sales in the United States, the conventional food industry is worried."[64]

In the UK, some of the debate has been summarized in an exchange between Prof A. Trewavas and Lord P. Melchett, and published by a major supermarket, concerned about examining the issues. Amongst many others, Trewavas[65] contests the notion that organic agricultural systems are more friendly to the environment and more sustainable than high-yielding farming systems.