Organic farming-companion plants

Companion planting is the planting of different crops in proximity (in gardening and agriculture), on the theory that they assist each other in nutrient uptake, pest control, pollination, and other factors necessary to increasing crop productivity. Companion planting is a form of poly culture.

Companion planting is used by farmers and gardeners in both industrialized and developing countries for many reasons. Many of the modern principles of companion planting were present many centuries ago in cottage gardens in England and home gardens in Asia.

For farmers using an integrated pest management system, increased yield and/or reduction of pesticides is the goal. For gardeners, the combinations of plants also make for a more varied, attractive vegetable garden, as well as allowing more productive use of space

In China, the mosquito fern has been used for at least one thousand years, as a companion plant for rice crops. It hosts a special cyanobacteria that fixes nitrogen from the atmosphere, and also blocks out light from getting to any competing plants, aside from the rice, which is planted when tall enough to stick out of the water above the azolla layer.

Companion planting was practiced in various forms by Native Americans prior to the arrival of Europeans. One common system was the planting of corn and pole beans together. The cornstalk would serve as a trellis for the beans to climb while the beans would fix nitrogen for the corn. The inclusion of squash with these two plants completes the Three Sisters technique, pioneered by Native American peoples.

Companion planting was widely touted in the 1970s as part of the organic gardening movement. It was encouraged for pragmatic reasons, such as natural trellising, but mainly with the idea that different species of plant may thrive more when close together. It is also a technique frequently used in permaculture, together with mulching, poly culture, and changing of crops.

Organic farming-crop rotation

Effects of crop rotation & monoculture: On the left field, the "Norfolk" crop rotation sequence (potatoes, oats, peas, rye) is being applied; on the right field, rye has been grown for 45 years in a row. (Source: Swojec Experimental Farm, Wroclaw University of Environmental and Life Sciences.)

Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons for various benefits such as to avoid the build-up of pathogens and pests that often occurs when one species is continuously cropped. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops. It is one component of poly culture. Crop rotation can also improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants.

Crop rotation avoids a decrease in soil fertility, as growing the same crop in the same place for many years in a row disproportionately depletes the soil of certain nutrients. With rotation, a crop that leaches the soil of one kind of nutrient is followed during the next growing season by a dissimilar crop that returns that nutrient to the soil or draws a different ratio of nutrients, for example, rice followed by cotton.

Organic farming

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.
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

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).