Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed vegetation, or "slash", is then left to dry, usually right before the rainiest part of the year. Then, the biomass is burned, resulting in a nutrient-rich layer of ash which makes the soil fertile, as well as temporarily eliminating weed and pest species. After about three to five years, the plot's productivity decreases due to depletion of nutrients along with weed and pest invasion, causing the farmers to abandon the field and move to a new area. The time it takes for a swidden to recover depends on the location and can be as little as five years to more than twenty years, after which the plot can be slashed and burned again, repeating the cycle.[1][2] In Bangladesh and India, the practice is known as jhum or jhoom.[3][4][5]
Slash-and-burn is a type of shifting cultivation, an agricultural system in which farmers routinely move from one cultivable area to another. A rough estimate is that 250 million people worldwide use slash-and-burn.[6][bettersourceneeded] Slash-and-burn causes temporary deforestation. Ashes from the burnt trees help farmers by providing nutrients for the soil.[7] In low density of human population this approach is very sustainable but the technique is not scalable for large human populations.[8]
A similar term is assarting, which is the clearing of forests, usually (but not always) for the purpose of agriculture. Assarting does not include burning.[9]
History
Historically, slash-and-burn cultivation has been practiced throughout much of the world. Fire was already used by hunter-gatherers before the invention of agriculture, and still is in present times. Clearings created by the fire were made for many reasons, such as to provide new growth for game animals and to promote certain kinds of edible plants.
During the Neolithic Revolution, groups of hunter-gatherers domesticated various plants and animals, permitting them to settle down and practice agriculture, which provided more nutrition per hectare than hunting and gathering. Some groups could easily plant their crops in open fields along river valleys, but others had forests covering their land. Thus, since Neolithic times, slash-and-burn agriculture has been widely used to clear land to make it suitable for crops and livestock.[10]
Large groups wandering in the woodlands was once a common form of society in European prehistory. The extended family burned and cultivated their swidden plots, sowed one or more crops, and then proceeded on to the next plot.[11]
Technique
Slash-and-burn agriculture in Maaninka, Finland, in the 1920s
Slash-and-burn fields are typically used and owned by a family until the soil is exhausted. At this point the ownership rights are abandoned, the family clears a new field, and trees and shrubs are permitted to grow on the former field. After a few decades, another family or clan may then use the land and claim usufructuary rights. In such a system there is typically no market in farmland, so land is not bought or sold on the open market and land rights are traditional.[citation needed]
In slash-and-burn agriculture, forests are typically cut months before a dry season. The "slash" is permitted to dry and then burned in the following dry season. The resulting ash fertilizes the soil[12][13] and the burned field is then planted at the beginning of the next rainy season with crops such as rice, maize, cassava, or other staples. This work was once done using simple tools such as machetes, axes, hoes and shovels.
This system of agriculture provides millions of people with food and income. It has been ecologically sustainable for thousands of years. Because the leached soil in many tropical regions, such as the Amazon, are nutritionally extremely poor, slash-and-burn is one of the only types of agriculture which can be practiced in these areas. Slash-and-burn farmers typically plant a variety of crops, instead of a monoculture, and contribute to a higher biodiversity due to creating mosaic habitats. The general ecosystem is not harmed in traditional slash-and-burn, aside from a small temporary patch.
This technique is most unsuitable for the production of cash crops. A huge amount of land, or a low density of people, is required for slash-and-burn. When slash-and-burn is practiced in the same area too often, because the human population density has increased to an unsustainable level, the forest will eventually be destroyed.
Regionally
South Asia
Tribal groups in the northeastern Indian states of Tripura, Arunachal Pradesh, Meghalaya, Mizoram and Nagaland and the Bangladeshi districts of Rangamati, Khagrachari, Bandarban and Sylhet refer to slash-and-burn agriculture as podu, jhum or jhoom cultivation. The system involves clearing land, by fire or clear-felling, for economically important crops such as upland rice, vegetables or fruits. After a few cycles, the land's fertility declines and a new area is chosen. Jhum cultivation is most often practiced on the slopes of thickly-forested hills. Cultivators cut the treetops to allow sunlight to reach the land, burning the trees and grasses for fresh soil. Although it is believed that this helps fertilize the land, it can leave it vulnerable to erosion. Holes are made for the seeds of crops[14] such as sticky rice, maize, eggplant and cucumber. After considering jhum's effects, the government of Mizoram has introduced a policy to end the method in the state.[15]
Americas
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Telkkämäki Nature Reserve in Kaavi, Finland, is an open-air museum where slash-and-burn agriculture is demonstrated. Farm visitors can see how people farmed when slash-and-burn was the norm in the Northern Savonian region of eastern Finland beginning in the 15th century. Areas of the reserve are burnt each year.[19]
Svedjebruk is a Swedish and Norwegian term for slash-and-burn agriculture derived from the Old Norse word sviða, which means "to burn". This practice originated in Russia in the region of Novgorod and was widespread in Finland and Eastern Sweden during the Medieval period. It spread to western Sweden in the 16th century when Finnish settlers were encouraged to migrate there by King Gustav Vasa to help clear the dense forests. Later, when the Finns were persecuted by the local Swedes, svedjebruk farming was spread by refugees to eastern Norway, more specifically in the eastern part of Solør, in the area bordering Sweden known as Finnskogen ("the Finnish woods").
The practice also spread to New Sweden in North America. Reinforced by the use of fire in agriculture and hunting by American Indians, it became an important part of pioneering in America.[16]
Svedjebruk involved stripping a ring of bark completely around the trunk of coniferous trees like pine or spruce or felling them, allowing them to dry, setting fire to the dried forest and growing crops on the fertile ash-covered soil. The resulting ash was highly fertile, but only for a short period. The clearing was initially planted to rye as soon as the ash had fully settled and sufficiently cooled. When the rain came, it packed the ash around the rye. The rye germinated and grew prolifically, with anywhere from 25 to 100 stalks (or straws), each with multiple grains.
Only two tools were required, the axe and the sickle. The axe cut the trees to start the cycle. When the rye had ripened, it was harvested with a sickle, which could reach among the rocks and stumps where a scythe would have been ineffective.[20]
In the second and third year the field would be sown with turnips or cabbages. It then might be grazed for several years before being allowed to return to woodland.
Svedjebruk required felling new forest and burning a new area every year. It was necessary to allow the former fields to regrow with forest for 10–30 years before repeating the cycle. As a result, the dwellings were often many kilometers from the fields. Furthermore, since the process was man-power intensive, extended families tended to work together and live in compact communities.
The svedjebruk farming approach required a large area. When forest was plentiful, the Finns were very prosperous. As population grew and restrictions were placed on the forest which could be burned, it became increasingly difficult. By 1710, during the conflict with Sweden, because of their suspect loyalties Norwegian authorities considered expelling them from the border area, but did not do so because it was judged they were too poor to survive if evicted.
Research
This type of agriculture is discouraged by many developmental or environmentalist organisations, with the main alternatives being promoted as switching to more intensive, permanent farming methods, or promoting a shift from farming to working in different, higher-paying industries altogether. Other organisations promote helping farmers achieve higher productivity by introducing new techniques.[citation needed]
Not allowing the slashed vegetation to burn completely and ploughing the resultant charcoal into the soil (slash-and-char) has been proposed as a way to boost yields.[21]
Promoters of a project from the early 2000s claimed that slash-and-burn cultivation could be reduced if farmers grew black pepper crops, turmeric, beans, corn, cacao, rambutan, and citrus between Inga trees, which they termed 'Inga alley cropping'.[22][23]
A method of improving the yields in a type of traditional assarting cultivation used to grow common beans in Central America called 'slash-and-cover' has been proposed by additionally planting leguminous shrubs to act as a fallow crop after the soil is exhausted and one is ready to clear a new patch of forest.[24]
Pyne, Stephen J. (1997). Vestal Fire: An Environmental History, Told Through Fire, of Europe and Europe's Encounter with the World. Seattle and London: University of Washington Press. ISBN0-295-97596-2.
↑ Md Shahidul Islam (2012). "Jhum". In Sirajul Islam and Ahmed A. Jamal (ed.). Banglapedia: National Encyclopedia of Bangladesh (Seconded.). Asiatic Society of Bangladesh.
↑ Choudhury, Sanjoy (March–April 2010). "Jhum". Geography and You. Vol.10, no.59. Archived from the original on 4 March 2019.
↑ Biederman, L. A. (31 December 2012). "Biochar and its effects on plant productivity and nutrient cycling: a meta-analysis". GCB Bioenergy. 5 (2): 202–214. doi:10.1111/gcbb.12037. S2CID86216355.
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing, rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth).
The following outline is provided as an overview of and topical guide to agriculture:
Shifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned while post-disturbance fallow vegetation is allowed to freely grow while the cultivator moves on to another plot. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, when the field is overrun by weeds. The period of time during which the field is cultivated is usually shorter than the period over which the land is allowed to regenerate by lying fallow.
Subsistence agriculture occurs when farmers grow crops on smallholdings to meet the needs of themselves and their families. Subsistence agriculturalists target farm output for survival and for mostly local requirements. Planting decisions occur principally with an eye toward what the family will need during the coming year, and only secondarily toward market prices. Tony Waters, a professor of sociology, defines "subsistence peasants" as "people who grow what they eat, build their own houses, and live without regularly making purchases in the marketplace".
Agriculture in Mesoamerica dates to the Archaic period of Mesoamerican chronology. At the beginning of the Archaic period, the Early Hunters of the late Pleistocene era led nomadic lifestyles, relying on hunting and gathering for sustenance. However, the nomadic lifestyle that dominated the late Pleistocene and the early Archaic slowly transitioned into a more sedentary lifestyle as the hunter gatherer micro-bands in the region began to cultivate wild plants. The cultivation of these plants provided security to the Mesoamericans, allowing them to increase surplus of "starvation foods" near seasonal camps; this surplus could be utilized when hunting was bad, during times of drought, and when resources were low. The cultivation of plants could have been started purposefully, or by accident. The former could have been done by bringing a wild plant closer to a camp site, or to a frequented area, so it was easier access and collect. The latter could have happened as certain plant seeds were eaten and not fully digested, causing these plants to grow wherever human habitation would take them.
Dryland farming and dry farming encompass specific agricultural techniques for the non-irrigated cultivation of crops. Dryland farming is associated with drylands, areas characterized by a cool wet season followed by a warm dry season. They are also associated with arid conditions, areas prone to drought and those having scarce water resources.
Agroforestry is a land use management system that integrates trees with crops or pasture. It combines agricultural and forestry technologies. As a polyculture system, an agroforestry system can produce timber and wood products, fruits, nuts, other edible plant products, edible mushrooms, medicinal plants, ornamental plants, animals and animal products, and other products from both domesticated and wild species.
Worldwide more human beings gain their livelihood from agriculture than any other endeavor; the majority are self-employed subsistence farmers living in the tropics. While growing food for local consumption is the core of tropical agriculture, cash crops are also included in the definition.
Agriculture employs the majority of Madagascar's population. Mainly involving smallholders, agriculture has seen different levels of state organisation, shifting from state control to a liberalized sector.
The southeast Asian country of Laos, with a landmass of 23.68 million hectares, has at least 5 million hectares of land suitable for cultivation. Seventeen percent of this land area is actually cultivated, less than 4 percent of the total area.
Agriculture in Myanmar is the main industry in the country, accounting for 60 percent of the GDP and employing some 65 percent of the labour force. Burma was once Asia's largest exporter of rice, and rice remains the country's most crucial agricultural commodity.
Chitemene, from the ciBemba word meaning “place where branches have been cut for a garden”, is a system of slash and burn agriculture practiced throughout northern Zambia. It involves coppicing or pollarding of standing trees in a primary or secondary growth Miombo woodland, stacking of the cut biomass, and eventual burning of the cut biomass in order to create a thicker layer of ash than would be possible with in situ burning. Crops such as maize, finger millet, sorghum, or cassava are then planted in the burned area.
Thysanolaena is a monotypic genus of the grass family, in the tribe Thysanolaeneae. Its only recognized species is Thysanolaena latifolia, native to Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Sri Lanka, Taiwan, Thailand, and Vietnam. It is also naturalized in Mauritius, Seychelles, Gambia, Tanzania, Hawaii, California, the West Indies and Brazil. Tiger grass, Nepalese broom grass, broom grass, broom stick are common names for this plant, in Nepali amliso and jharu in Assamese. The flowers of this plant are used as cleaning tool or broom, which is known askuchcho in Nepali and jhadu in Hindi.
Deforestation in Madagascar is an ongoing environmental issue. Deforestation creates agricultural or pastoral land but can also result in desertification, water resource degradation, biodiversity erosion and habitat loss, and soil loss.
Indigenous horticulture is practised in various ways across all inhabited continents. Indigenous refers to the native peoples of a given area and horticulture is the practice of small-scale intercropping.
Farming systems in India are strategically utilized, according to the locations where they are most suitable. The farming systems that significantly contribute to the agriculture of India are subsistence farming, organic farming, industrial farming. Regions throughout India differ in types of farming they use; some are based on horticulture, ley farming, agroforestry, and many more. Due to India's geographical location, certain parts experience different climates, thus affecting each region's agricultural productivity differently. India is very dependent on its monsoon cycle for large crop yields. India's agriculture has an extensive background which goes back to at least 9 thousand years. In India, in the alluvial plains of the Indus River in Pakistan, the old cities of Mohenjo-Daro and Harappa experienced an apparent establishment of an organized farming urban culture. That society, known as the Harappan or Indus civilization, flourished until shortly after 4000 BP; it was much more comprehensive than those of Egypt or Babylonia and appeared earlier than analogous societies in northern China. Currently, the country holds the second position in agricultural production in the world. In 2007, agriculture and other industries made up more than 16% of India's GDP. Despite the steady decline in agriculture's contribution to the country's GDP, agriculture is the biggest industry in the country and plays a key role in the socio-economic growth of the country. India is the second-largest producer of wheat, rice, cotton, sugarcane, silk, groundnuts, and dozens more. It is also the second biggest harvester of vegetables and fruit, representing 8.6% and 10.9% of overall production, respectively. The major fruits produced by India are mangoes, papayas, sapota, and bananas. India also has the biggest number of livestock in the world, holding 281 million. In 2008, the country housed the second largest number of cattle in the world with 175 million.
The environmental impact of cocoa production includes deforestation, soil contamination, and herbicide resistance. The majority of cocoa farms are now located in Ivory Coast and Ghana.
The Telkkämäki Nature Reserve is an open-air museum and a heritage farm in the municipality of Kaavi, in the Northern Savonia region of Finland. It covers one square kilometer.
This glossary of agriculture is a list of definitions of terms and concepts used in agriculture, its sub-disciplines, and related fields, including horticulture, animal husbandry, agribusiness, and agricultural policy. For other glossaries relevant to agricultural science, see Glossary of biology, Glossary of ecology, Glossary of environmental science, and Glossary of botanical terms.
Jhum cultivation is the traditional shifting cultivation farming technique that is practised in certain parts of Northeast India and also by the indigenous communities in Chittagong Hill Tracts of Bangladesh. It is a traditional agricultural technique that involves clearing land of trees and other vegetation, burning it, and then cultivating it for a set number of years. Shifting cultivation and slash and burn cultivation are other terms for jhum cultivation.
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