Organic farming methods combine scientific knowledge of ecology and some modern
technology with
traditional farming practices based on naturally occurring biological processes. Organic farming methods are studied in the field of
agroecology. While conventional agriculture uses synthetic pesticides and water-soluble synthetically purified fertilizers, organic farmers are restricted by regulations to using natural pesticides and fertilizers. An example of a natural pesticide is
pyrethrin, which is found naturally in the
Chrysanthemum flower. The principal methods of organic farming include
crop rotation,
green manures and
compost,
biological pest control, and mechanical
cultivation. These measures use the natural environment to enhance agricultural productivity:
legumes are planted to fix
nitrogen into the soil,
natural insect predators are encouraged, crops are rotated to confuse pests and renew soil, and natural materials such as
potassium bicarbonate and
mulches are used to control disease and
weeds.
Genetically modified seeds and animals are excluded. While organic is fundamentally different from conventional because of the use of carbon-based fertilizers compared with highly soluble synthetic based fertilizers and
biological pest control instead of synthetic pesticides, organic farming and large-scale conventional farming are not entirely mutually exclusive. Many of the methods developed for organic agriculture have been borrowed by more conventional agriculture. For example,
Integrated Pest Management is a multifaceted strategy that uses various organic methods of pest control whenever possible, but in conventional farming could include synthetic
pesticides only as a last resort. Examples of beneficial insects that are used in organic farming include ladybugs and lacewings, both of which feed on aphids. The use of IPM lowers the possibility of pest developing resistance to pesticides that are applied to crops.
Crop diversity Organic farming encourages
crop diversity by promoting
polyculture (multiple crops in the same space). Planting a variety of
vegetable crops supports a wider range of beneficial insects, soil microorganisms, and other factors that add up to overall farm health.
Crop diversity helps the environment to thrive and protects species from going extinct. The science of
Agroecology has revealed the benefits of polyculture, which is often employed in organic farming. Agroecology is a scientific discipline that uses ecological theory to study, design, manage, and evaluate
agricultural systems that are productive and resource-conserving, and that are also culturally sensitive, socially just, and economically viable. Incorporating crop diversity into organic farming practices can have several benefits. For instance, it can help to increase
soil fertility by promoting the growth of beneficial soil
microorganisms. It can also help to reduce pest and disease pressure by creating a more diverse and resilient
agroecosystem. Furthermore, crop diversity can help to improve the nutritional quality of food by providing a wider range of essential
nutrients.
Soil management Organic farming relies more heavily on the natural breakdown of organic matter than the average conventional farm, using techniques like
green manure and
composting, to replace nutrients taken from the soil by previous crops. This biological process, driven by
microorganisms such as
mycorrhiza and
earthworms, releases nutrients available to plants throughout the growing season. Farmers use a variety of methods to improve soil fertility, including crop rotation, cover cropping, reduced tillage, and application of compost. By reducing fuel-intensive tillage, less soil organic matter is lost to the atmosphere. This has an added benefit of
carbon sequestration, which reduces greenhouse gases and helps reverse climate change. Reducing tillage may also improve soil structure and reduce the potential for soil erosion.
Plants need a large number of nutrients in various quantities to flourish. Supplying enough
nitrogen and particularly synchronization, so that plants get enough nitrogen at the time when they need it most, is a challenge for organic farmers.
Crop rotation and green manure ("
cover crops") help to provide nitrogen through
legumes (more precisely, the family
Fabaceae), 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. Organic farmers integrate cultural, biological, mechanical, physical and chemical tactics to manage weeds without synthetic
herbicides. Organic standards require
rotation of annual crops, 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 person. 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. •
Tillage - Turning the soil between crops to incorporate crop residues and soil amendments; remove existing weed growth and prepare a seedbed for planting; turning soil after seeding to kill weeds, including
cultivation of row crops. • Mowing and cutting - Removing top growth of weeds. • Flame weeding and thermal weeding - Using heat to kill weeds. •
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. 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.
Controlling other organisms is used for pest management in organic rice cultivation in Chhattisgarh, India. Organisms aside from weeds that cause problems on farms include
arthropods (e.g., insects,
mites),
nematodes,
fungi and
bacteria. Practices include, but are not limited to: Examples of predatory 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. These pesticides are not always more safe or environmentally friendly than synthetic pesticides and can cause harm. The main criterion for organic pesticides is that they are naturally derived, and some naturally derived substances have been controversial. Controversial natural pesticides include rotenone,
copper,
nicotine sulfate, and pyrethrums Rotenone and pyrethrum are particularly controversial because they work by attacking the nervous system, like most conventional insecticides. Rotenone is extremely toxic to fish and can induce symptoms resembling Parkinson's disease in mammals. Although pyrethrum (natural pyrethrins) is more effective against insects when used with piperonyl butoxide (which retards degradation of the pyrethrins), organic standards generally do not permit use of the latter substance. 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.
Compost tea contains a mix of beneficial microbes, which may attack or out-compete certain plant pathogens, but variability among formulations and preparation methods may contribute to inconsistent results or even dangerous growth of toxic microbes in compost teas. Some naturally derived pesticides are not allowed for use on organic farms. These include nicotine sulfate,
arsenic, and
strychnine. 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. Similar concerns apply to copper hydroxide. Repeated application of copper sulfate or copper hydroxide as a fungicide may eventually result in copper accumulation to toxic levels in soil, and admonitions to avoid excessive accumulations of copper in soil appear in various organic standards and elsewhere. Environmental concerns for several kinds of biota arise at average rates of use of such substances for some crops. In the European Union, where replacement of copper-based fungicides in organic agriculture is a policy priority, research is seeking alternatives for organic production.
Livestock Raising livestock and poultry, for meat, dairy and eggs, is another traditional farming activity that complements growing. Organic farms attempt to provide animals with natural living conditions and feed. Organic certification verifies that livestock are raised according to the USDA organic regulations throughout their lives. These regulations include the requirement that all animal feed must be certified organic. Organic livestock may be, and must be, treated with medicine when they are sick, but drugs cannot be used to promote growth, their feed must be organic, and they must be pastured. Also, horses and cattle were once a basic farm feature that provided labour, for hauling and plowing, fertility, through recycling of manure, and fuel, in the form of food for farmers and other animals. While today, small growing operations often do not include livestock, domesticated animals are a desirable part of the organic farming equation, especially for true sustainability, the ability of a farm to function as a self-renewing unit.
Genetic modification A key characteristic of organic farming is the exclusion of genetically engineered plants and animals. On 19 October 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 organic 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. Organic farmer Raoul Adamchak and geneticist
Pamela Ronald write that many agricultural applications of
biotechnology are consistent with organic principles and have significantly advanced sustainable agriculture. 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. Differing regulations among countries limits the availability of GMOs to certain countries, as described in the article on
regulation of the release of genetic modified organisms.
Tools Organic farmers use a number of traditional
farm tools to do farming, and may make use of
agricultural machinery in similar ways to conventional farming. In the developing world, on small organic farms, tools are normally constrained to hand tools and
diesel powered water pumps. == Standards ==