Saturday, 30 May 2009
Agricultural contaminants such as inorganic fertilizers, herbicides and insecticides from conventional agriculture are a major concern all over the world.
Eutrophication, the suffocation of aquatic plants and animals due to rapid growth of algae, referred to as "algae blooms", are literally killing lakes, rivers and other bodies of water. Persistent herbicides and insecticides can extend beyond target weeds and insects when introduced into aquatic environments. These chemicals have accumulated up the food chain whereby top predators often consume toxic dosages. Organic agriculture restores the environmental balance and has none of these or other such deleterious effects on the environment.
A wide range of organisms benefit from organic farming, but it is unclear whether organic methods confer greater benefits than integrated agri-environmental conventional programs.
Organic crops use little or no herbicides and pesticides and thus biodiversity fitness and population density benefit. Many weed species attract beneficial insects that improve soil qualities and forage on weed pests. Soil-bound organisms often benefit because of increased bacteria populations due to natural fertilizer spread and reduced intake of herbicides and pesticides. 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.
Agriculture relies on roughly one meter of topsoil, and that is being depleted ten times faster than it is being replaced.
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 manure applications in organic farming are better at building up the soil than no-till despite tillage.
Mitigate Climate Change
Organic agriculture can reduce greenhouse gas emissions by effectively locking more carbon into the soil rather than releasing it into the atmosphere. Application of compost, mulch, green manure etc introduced more organic matter in to the soil, locking up carbon and keeping it out of the atmosphere. Scientists also believe that emission of methane gas, a noxious greenhouse gas, from conventional animal husbandry, could be cut dramatically by feeding the cows with leguminous foliage.
Production of ammonium nitrate fertilizer, which is indispensable in conventional faring, produces NO2, another greenhouse gas. Organic farming, which excludes application of chemical fertilizers, too will remove the potential emission of NO2 into the atmosphere.
Food Quality & Safety
Organic food is widely believed by the lay public to be healthier than conventional food, although the research is inconclusive. Organic produce is likely to have less agrochemical residues, but these residues are generally below the acceptable daily intake and their health impact is questionable. Organic food also appears to have lower nitrate concentrations, but the health impact of nitrates is debated. However, studies show both organic and conventional food are expected to have similar concentrations of persistent organic pollutants and heavy metals.
Currently, we use around 10 calories of fossil energy to produce one calorie of food energy. Studies by the Department for Environment, Food and Rural Affairs shows that, on average, organically grown crops use 25% less energy than conventional agricultural.
The organic movement was born out of a commitment to provide local food for local people, and so it is logical that organic marketing encourages localisation through veg boxes, farm shops and stalls. Local distribution and consumption (such as organic box schemes), energy used dwindled to a fraction of that needed for an intensive, centralised food system.
Friday, 29 May 2009
Wendell Berry "The Gift of Good Land"
Organic farming is a production system which favors maximum use of organic material and discourage use of synthetically produced agro-inputs, for maintaining soil productivity and fertility and pest management under conditions of sustainable natural resources and healthy environment.
Plants rely primarily on soil for water and nutrients. It is therefore soil health is utmost important for organic farmers. But providing adequate nutrients is often a challenge.
Crop rotation, green manure, intercropping, cover cropping, mulching etc., help to provide nutrient to the soil, as well as increasing the soil’s organic matter. Certain processed fertilizers such as seed meals, compost, bloodmeal, animal excreta, naturally-occurred-fertilizer, eg. rock phosphate and limestone are used. Altogether these methods help to control erosion, promote biodiversity, and enhance the health of the soil.
Weed control is the botanical component of pest control, stopping weeds from reaching a mature stage of growth when they could be harmful to domesticated plants and livestock.
Typically, a combination of methods is used in organic farming. The most basic is manual weeding, with hand or aided with some simple tools. Flaming, a traditional technique is sometime used, but subjected to local legislation. Mechanically tilling and ploughing, are effective ways to control weeds, were however involve diesel-powered tractor, unfortunately which is not an environmental-friendly machine. Other techniques for controlling weeds include mulch, solarization, crop rotation, drip-irrigation ( limit weeds access to water ) natural pre-emergence herbicide ( e.g. corn gluten meal, garlic, clove oil, borax, pelargonic acid, table salt, vinegar, and various other homemade remedies).
Control Other Organisms
Organisms aside from weeds which cause problems include athropods (e.g. insects, mites) and nematodes. Fungi and bacteria can cause disease.
Insect pests are a common problem, and insecticides, both non-organic and organic, are controversial due to their environmental and health effects. One way to manage insects is to ignore them and focus on plant health, since plants can survive the loss of about a third of lead area before suffering severe growth consequences.
To avoid using insecticides, one can select naturally-resistant plants, put bags around the plants, remove dying material such as leaves, fruit, and diseased plants, covering plants with a solid barrier ("row cover"), hosing, encouraging and releasing beneficial organisms and beneficial insects, planting companion plants and polycultures, various traps, sticky cards and season extension. Biological pest control uses natural predators to control pests. Recommended beneficial insects include minute pirate bugs, big-eyed bugs, ladybugs, lacewings, parasitoid wasps, praying mantis and predatory mites.
Several of pesticides approved for organic use have been called green pesticides such as spinosad and neem. Generally, but not necessarily, organic pesticides are safer and more environmentally friendly than synthetic pesticides. The main three organic insecticides used are Bt (a bacterial toxin), pyrethrum and rotenone. Nicotine sulfate may also be used; although it breaks down quickly, it is extremely toxic, nearly as toxic as aldicarb. Less toxic but still effective organic insecticides include neem, spinosad, soaps, garlic, citrus oil, capsaicin (repellent), Bacillus popillae, Beauvaria bassiana, and boric acid. Pesticides should be rotated to minimize pest resistance.
The first disease control strategy involves keeping the area clean by removing diseased and dying plants and ensure that the plants are healthy by maintaining water and fertilization. Polycultures reduce the ability of disease to spread. Disease-resistant cultivars can be purchased. Organic fungicide include the bacteria Bacillus subtilis, Bacillus pumilus, and Trichoderma harzianum which are mainly effective for diseases affecting roots. Bordeaux mix, sulfur, lime sulfur, potassium and sodium bicarbonate can be used as an organic fungicide in various forms
Thursday, 28 May 2009
Requirements generally involve a set of production standards for growing, storage, processing, packaging and shipping that include:
- avoidance of most synthetic chemical inputs (e.g. fertilizer, pesticides, antibiotics, food additives, etc), genetically modified organisms, irradiation, and the use of sewage sludge;
- use of farmland that has been free from chemicals for a number of years (often, three or more);
- keeping detailed written production and sales records (audit trail);
- maintaining strict physical separation of organic products from non-certified products;
- undergoing periodic on-site inspections.
The first use of the term "organic farming" is by Lord Northbourne (aka Walter James, 4th Baron Northbourne). The term derives from his concept of "the farm as organism", which he expounded in his book, Look to the Land (1940), and in which he described a holistic, ecologically balanced approach to farming. Northbourne wrote of "chemical farming versus organic farming". http://www.orgprints.org/10138.
Sir Albert Howard's 1940 book, An Agricultural Testament, was influential in promoting organic techniques, and his 1947 book "The Soil and Health, A Study of Organic Agriculture" adopted Northbourne's terminology and was the first book to include "organic" agriculture or farming in its title.
In 1939, strongly influenced by Sir Howard's work, Lady Eve Balfour launched the Haughley Experiment on farmland in England. It was the first, side-by-side comparison of organic and conventional farming. Four years later, she published The Living Soil, based on the initial findings of the Haughley Experiment. It was widely read, and lead to the formation of a key international organic advocacy group, the Soil Association.
During the 1950s, sustainable agriculture was a research topic of interest. The science tended to concentrate on the new chemical approaches. In the U.S., J.I. Rodale began to popularize the term and methods of organic growing. In addition to agricultural research, Rodale's publications through the Rodale Press helped to promote organic gardening to the general public.
In 1962, Rachel Carson, a prominent scientist and naturalist, published Silent Spring, chronicling the effects of DDT and other pesticides on the environment. A bestseller in many countries, including the US, and widely read around the world, Silent Spring was instrumental in the US government's 1972 banning of DDT. The book and its author are often credited with launching the environmental movement.
In the 1970s, worldwide movements concerned with environmental pollution caused by persistent agrichemical increased attention on organic farming. One goal of the organic movement was to promote consumption of locally grown food, which was promoted through slogans such as "Know Your Farmer, Know Your Food".
In 1972, the International Federation of Organic Agriculture Movements (IFOAM), was founded in Versailles, France. IFOAM was dedicated to the diffusion of information on the principles and practices of organic agriculture across national and linguistic boundaries.
In the 1980s, around the world, various farming and consumer groups began seriously pressuring for government regulation of organic production to ensure standards of production.
This led to various legislation and certification standards being enacted through the 1990s and to date. Currently, most aspects of organic food production are government-regulated in the US and the European Union.
In the 2000s, the worldwide market for organic products (including food, beauty, health, bodycare, and household products, and fabrics) has grown rapidly. More countries are establishing formal, government-regulated certification of organic food: in 2002 in the US, in 2005 in China http://eprints.utas.edu.au/895/ and projected for 2006 in Canada, among others. Monitoring and challenging certification rules and decisions have become a regular, high profile aspect of activists in the organic movement.
“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.”
Directorate General for Agriculture and Rural Development of the European Commission
“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.”
"Organic agriculture is an ecological production management system that promotes and enhances biodiversity, biological cycles and soil biological activity.
It is based on minimal use of off-farm inputs and on management practices that restore, maintain and enhance ecological harmony. "
National Organic Standard Board
“Organic farming is the process of producing food naturally.
This method avoids the use of synthetic chemical fertilizers and genetically modified organisms to influence the growth of crops.
The main idea behind organic farming is 'zero impact' on the environment.
The motto of the organic farmer is to protect the earth’s resources and produce safe, healthy food.”
“Vegetable and livestock production using natural sources of nutrients and natural methods of crop and weed control, instead of using synthetic or inorganic agrochemicals. Also called low input farming.”
“Organic farming is a sustainable agricultural with good land-stewardship.
The objective is to produce safe, healthy & affordable food for local community, with minimal-impact on the environment. It should be practiced based on good agricultural practices, and limiting the use o f synthetic agrochemicals, and excluding use of GMOs”
Wednesday, 27 May 2009
Friday, 22 May 2009
Common names include Black Wattle,
Acacia mangium grows best in warm climates with 1500 to 3000 mm of mean annual rainfall. These soils are acid with medium-to-low fertility and can be poorly drained. Soils with high pH are not tolerated.
Acacia mangium is a fast-growing, medium-sized, evergreen tree with phyllodes that serve as leaves. Trees reach 30 m in height and 60 cm in diameter in their native range. The bark is reddish brown and lightly furrowed
Branchlets, phyllodes and petioles glabrous or slightly scurfy. Phyllodes 5-10 cm broad, 2-4 times as long as broad, dark green, chartaceous when dry. The phyllodes have (3-)4 longitudinal main nerves which join on the dorsal margin at the base of the phyllode, secondary nerves fine and inconspicuous.
The dark brown, crinkled, and coiled ripe pods partially open, and the small (2.5 by 4 mm), black seeds hang by orange, fleshy funicles. The seeds are dispersed when small birds consume the oily funicle or they eventually fall to the ground under the mother trees. Individual trees in an A. mangium plantation produced 1 kg of seed per year
Acacia mangium is planted primarily for site rehabilitation. Its quick growth and dense shade make it an effective tool in reforesting Imperata grass swards and reducing fire risk. Its ability to grow well on infertile soils, especially those low in phosphorus, make it a favorite for rehabilitation of mine spoils and eroded sites. The tree also produces a usable wood. It is hard and has an air-dry specific gravity of 0.69. The sapwood is cream colored; the heartwood is yellow-brown. The wood is suitable for particleboard, plywood, veneer, pulp, fenceposts, firewood, and charcoal. The leaves can be used as livestock fodder
Francis, John K. , 2003, "Acacia mangium Willd" , Tropical Tree Seed Manual. Reforestation, Nurseries & Genetics Resources.