Slash and Burn Agriculture

9 Key excerpts on "Slash and Burn Agriculture"

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  A History of World Agriculture

  From the Neolithic Age to the Current Crisis

  • Marcel Mazoyer, Laurence Roudart(Authors)
  • 2006(Publication Date)
  • Monthly Review Press

    (Publisher)

  3Systems of Slash-and-Burn Agriculture in Forest Environments:

  Deforestation and the Formation of Post-Forest Agrarian Systems

  Humanity, disdainful of what was created without it, believes ... that it can develop [the planet] by destroying the slow accumulation of plant wealth that collaboration between the atmosphere and the earth had produced over thousands of centuries. Will the large ... tropical ... forest, this huge laboratory of climates, this humid and warm velvet belt of plants from which rhythmic spirals of atmospheric waves harmoniously soar, be transformed wisely, exploited with respect for humanity and nature, by taking into account its relationship with the soil and the atmosphere, or will humanity give in to the temptation to assault the earth, attack the tropical forest quickly and without thought? In the latter case, if one thinks about it, it is humanity itself which would be endangered, ... because the atmosphere would be unbalanced and instability would be introduced into climates around the whole world.

  —F. SHRADER , Atlas de géographie historique , 1896

  Slash-and-burn agriculture is practiced in diverse wooded environments: amid mature trees, in a copse, shrubby or bushy thickets, wooded savanna, etc. It is established on terrains previously cleared by grubbing, that is, cutting followed by burning but without removing the stumps. The parcels thus cleared are only cultivated for one, two, or three years, rarely more, after which they are abandoned to return to their wooded wild state for one or more decades, before being cleared and cultivated again. Systems of slash-and-burn agriculture, also called forest agrarian systems , are thus characterized by the practice of temporary cultivation alternating with long-term wooded idling, forming a rotation with a period varying from about ten to fifty years.

  The origin of these systems goes back to the Neolithic epoch. From that time on, they spread to most of the forests and other cultivable wooded environments of the planet, where they lasted for thousands of years. In each region of the world, this pioneer dynamic accompanied a strong demographic growth and was pursued as long as uncleared, accessible wooded terrain remained. When all these virgin reserves were used and the population density continued to increase, the frequency and intensity of clearings increased, thus beginning a dynamic of deforestation of lands cultivated by slash-and-burn techniques. Ultimately, this resulted in the impossibility of pursuing this mode of cultivation. Deforestation generally resulted in deterioration of fertility, development of a more or less serious erosion problem, depending on the biotope, and worsening of the climate, even up to the point of desertification.

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  Properties and Management of Soils in the Tropics

  • Pedro A. Sanchez(Author)
  • 2019(Publication Date)
  • Cambridge University Press

    (Publisher)

  They are socially and environmentally sustainable, albeit at low levels of agri- cultural productivity. Shifting cultivation is also practiced in African woodland savannas, located between the humid forest and semiarid regions. In these ustic environments the vegetation is removed during the dry season by cutting scattered trees, uprooting the grasses and burning. The lack of sufficient biomass to burn often leads to cutting of a large area, with the biomass being concentrated in a much smaller area, where it is burned (Fig 16.4; Stromgaard 1991, Goma 2003). Farmers cut or slash the trees (called chitemene), the grasses are buried in the topsoil before burning (called fundikila), concentrating a hectare of biomass in a circle of about 0.1 hectare. Finger millet, a crop with low nutrient require- ments is planted and the yields are low. I have seen this practiced in the Miombo woodlands in northern Zambia on Oxisols and Ultisols, areas similar to the Brazilian Cerrado. 16.1.2 Slash-and-Burn Agriculture Traditional shifting cultivation is no longer practiced in large areas and it is replaced by less sustainable systems with shorter and shorter fallow periods as populations increase. When human population pressures exceed Boserup’s critical density of 30 people/km 2 , a wide variety of farming systems replace shifting cultivation, collectively described as “slash- and-burn agriculture” (Sanchez et al. 2005). They are charac- terized by short fallow periods (usually less than 10 years, and more commonly 2–4 years), which are incapable of accumulating sufficient biomass and nutrients in the fallow biomass. Weeds and soil erosion, which were seldom prob- lems in traditional shifting cultivation, become a serious problem in Slash and Burn Agriculture (Lal et al. 1986).

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  Management of Environmental Impacts

  • Alandra Kahl(Author)
  • 2017(Publication Date)
  • Momentum Press

    (Publisher)

  , associated with fish poisoning, which has been positively correlated to increased surface water temperatures in tropical oceans caused by the meteorological phenomenon El Niño (Moore et al. 2008). Changes in precipitation patterns linked to climate change can also influence the expression of eutrophication. For instance, an increase in precipitation may lead to changes in stratification patterns as more freshwater in the form of runoff (and associated desalinization) is discharged into coastal oceans, and will also translate into higher nutrient fluxes (Rabalais et al. 2008).

  3.1SLASH AND BURN FARMING IMPACTS AND CONTROLS

  Slash and Burn Agriculture is a destructive form of agriculture that is most widely used in rainforest areas, such as the Amazon. In this method of farming, cover vegetation such as trees and forest undergrowth is clear cut, and the resulting vegetation is burned to provide fertilizer and dispose of the covering plants. The land is then planted with the crop that is desired. As this method strips the land of nutrients by removing native vegetation, the area is only suitable for crops for a short time, sometimes as little as two to three years. The soil also loses valuable nutrients through erosion during the rainy season, as the covering root structure has been removed and the soil can then wash away. Nutrients are drained from the topsoil during the rainy season due to the lack of canopy cover and are baked off during the dry season for the same reason.

  Farmers try to lengthen the growing period in an area by applying soil amendments such as fertilizers and pesticides once the soil is exhausted. As the fertile topsoil layer has been eroded or overplanted, these measures are short-lived. Applied fertilizers and pesticides leach off of the amended land during the rainy season and pollute local waterways. During dry seasons, dust containing pesticides are carried by the winds to affect pristine areas.

  In areas that are less populated, slash and burn farming can be sustainable, as the land has time to recover and regrow between periods of burning. This buffer must be at least 5 years, ideally 10. As areas of the rainforests become more populated due to migration of native tribes today, this interval is not usually reached and the land remains infertile after use. In areas of rich vegetation and diverse habitat, this loss is irreparable.

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  Global Climate Change and Response of Carbon Cycle in the Equatorial Pacific and Indian Oceans and Adjacent Landmasses

  • Hodaka Kawahata, Yoshio A. Awaya(Authors)
  • 2006(Publication Date)
  • Elsevier Science

    (Publisher)

  Schimel et al., 2001 ).

  On the other hand, a number of studies have focused on ecosystem recovery through secondary succession in fallow areas (Tergas and Popenoe, 1971 ; Toky and Ramakrishnan, 1983 ; Williams-Linera, 1983 ; Uhl and Jordan, 1984 ; Kleinman et al., 1996 ; Palm et al., 1996 ; Lawrence and Schlesinger, 2001 ) and have reported that soil fertility can take from 5 years to more than 10 years of fallow to recover under traditional slash-and-burn agriculture (Nakano, 1978 ; Reading et al., 1995 ). While crop yields do indeed decline rapidly in traditional slash-and-burn agricultural areas, net primary productivity (NPP) can increase dramatically after abandonment in fallow (Uhl, 1987 ).

  Slash-and-burn agriculture is on the decline in temperate regions (Kang and Iizumi, 1981 ; Kamada et al., 1987 ; Hidaka et al., 1993 ). However, a unique agroforestry system exists in coastal mountain regions of central Japan to grow red turnips (Brassica rapa L. var. glabra Kitam.) and generate a value-added commodity. Under this unique agroforestry system, Japanese cedar (Cryptomeria japonica D. Don.) plantation is harvested for timber, the undergrowth and trimmings are burned, and a crop of red turnips is grown. There are some studies of the relationships between nutrient dynamics and microbial activity under slash-and-burn agriculture in temperate regions (Su et al., 1996 , 1997 ). However, few studies from temperate regions have suggested that the short-term losses from carbon pools caused by burning and fire induce change in soil CO2 efflux (Wüthrich et al., 2002

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  The Practice of Silviculture

  Applied Forest Ecology

  • Mark S. Ashton, Matthew J. Kelty(Authors)
  • 2018(Publication Date)
  • Wiley

    (Publisher)

  et al., 2000).

  Box 31.1 Bari swidden agriculture.

  Swiddening is an agroforestry system that is strongly successional. All swiddens temporarily clear a patch of forest within which agricultural crops (manioc, upland rice, vegetables) are cultivated for a number of years before the weeds become too competitive and/or the soil becomes depleted of nutrients. Cultivation is then stopped and the patch returns back to forest (Fig. 1 ). The forest that comes back can often contain trees of economic use, and some of these may have been planted. This new forest can be thinned and products are harvested before the cycle repeats itself. For that reason, swidden is also called shifting cultivation. This practice of switching between agriculture and forest on one patch of land has been its downfall in modern day land‐use planning (Padoch et al., 2007), where lands have been either demarcated for forestry or agriculture but not both (Agrawal and Sivaramakrishnan, 2001; Peluso and Vandergeest, 2001; van Noordwijk et al., 2008). This kind of planning was made particularly in forested biomes without serious consideration of what could or should be done if soils are not fertile enough to promote permanent and sedentary agriculture (Dove, 1983; Padoch et al., 2007).

  The Bari swidden system is an example of a complex temporal and spatial agroforestry system. The Bari are an indigenous South American people found in the Maracaibo region that includes the northeast borderlands between Colombia and Venezuela. Bari swidden agroforestry systems delineate crops by an annual or temporal zonation, rather than mixing crops together at one time. This is unusual, as most swidden systems rely upon sequential intercropping of mixtures of crops (Beckerman, 1987, 2013). In Bari swiddens, patches are usually small, less than 2.4 acres (1 ha), and typically the newly made field is planted with squash, sweet potato, and many varieties of manioc in separate areas (Beckerman, 2013). After the main crop of manioc has been harvested on several annual rotations (about 3 years), bananas and plantains are cultivated and harvested over the next 3–6‐year period. Afterwards, certain trees are interplanted such that by the 10th year, some of these trees are providing fruit. Once the weed growth has become impenetrable and difficult to cut back, the patch is abandoned to fallow. The fallow period after the final fruit tree crops have been harvested can last about 15 years before the land is cleared and the cultivation cycle resumes. Compared to other swidden systems, the Bari system is relatively simple and does not consist of a large diversity of crops (Beckerman, 2013). In other sections of this book, the Milpa swidden system of the Maya in the Yucatan, Mexico (Chapter 9 ) and the Yanomami of the Venezuelan and Brazilian Amazon (Chapter 1

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  Rice, Agriculture, and the Food Supply in Premodern Japan

  • Charlotte von Verschuer, Wendy Cobcroft, Charlotte Verschuer(Authors)
  • 2016(Publication Date)
  • Routledge

    (Publisher)

  Japanese archaeology has shown the existence of the practice of forest management by fire as well as the presence of edible plants in the Neolithic, from the 3rd millennium BC. Moreover, the land documents of the late medieval period (1200 – 1600) mention cases of swidden fields; and fire techniques are also attested, as we have seen, by the agricultural treatises of the Edo period (1603 – 1867). We can therefore speak of a continuity of fire agriculture over the millennia. The evidence that we have presented on the human management of edible plants in prehistoric times, far from consisting of isolated or marginal examples, only confirms a practice common to the subsequent historical periods. For the historical periods, we have discussed in this chapter several practices involving fire. The study of the administrative and poetic texts, lexicography and toponymy has enabled us to identify several techniques relating to a forest agriculture for the medieval period. Swidden farming (or assartage) involved cleaning by fire a patch of forest on a mountain side and cultivating it for a period limited to three or four years. Agri-sylviculture on a plot that had first undergone selective burning combined the cultivation of useful trees with cereal intercropping. The two systems of forest farming just mentioned were temporary and shifting. There was a third technique that cannot be regarded, strictly speaking, as a cultivation method: each year the Japanese of the early medieval period would set a running fire in wilderness areas intended for the harvesting of edible plants in order to promote their regrowth. As for land clearing aimed at permanent crops, it was done in the same way as for cleared plots intended for swidden fields

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  Available until 23 Dec |Learn more

  Fire

  A Brief History

  • Stephen J. Pyne(Author)
  • 2011(Publication Date)
  • University of Washington Press

    (Publisher)

  What we call “agriculture” thus became a practice of selective substitution, first of species, then of landscapes. The firestick farming of aborigines selects plants from among those that already exist at a place. Ax-and-plow farming goes further and creates suitable habitats for plants that come from elsewhere. Ultimately, it may fashion whole ecosystems: the “farm” brings its own plants and animals, fixes their relationships, lays down pathways of energy and nutrients. Such a system can even be exported in defiance of climate. The European agricultural mix, for example, collected together cereals, pulses, and herbivores from the winter-rains eastern Mediterranean, then thrust them into the summer-rains regime of temperate Europe. Something had to jolt and jostle the land for it to accept so startling a change. That something, of course, was fire.

  Nature supplied the model. Swidden farming mimics First Fire's storm-slashed and lightning-kindled woods. It is a small step, one many aboriginal peoples took, to assist the regrowth rising in the ash or to carry other plants to the cleaned site. The next step is to create those slashed and burned plots themselves. So, likewise, pastoralism echoes the movement of wildlife as they follow seasons and the patch-burns of green, scorched, and dormant forage. Replace the wild herds with domesticated livestock; then cycle them through similar landscapes; then create those landscapes by cutting, grazing, and burning.

  In fire-flushed and disturbance-rich places—which most agricultural hearths were—this transition can occur piece by piece, with the domestic replacing the wild as one might replace the tiles in a mosaic. People only had to tweak fire regimes to better suit their purposes; the border between aboriginal foraging and agricultural harvesting is murky because their fire practices are almost genetically related. That frontier appears most stark and the encounter most shocking when agriculture crashes into new lands, particularly places in which fire is scarce. When sun-craving cereals and grass-munching sheep and cattle try to enter sun-starved or tranquil woods, they require a more violent wrenching. Firestick farming need only massage the environment; ax-and-plow farming requires the ability to force fire whether the landscape naturally accepts it or not. Domestication requires more than simply loosing the hearth fire into the bush, which is no better than daubing the scrub with a firestick unless fuels are there to accept it. That—the labor of creating combustibles—is, from a fire-historical perspective, what moves the practice into true agriculture.

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  Swidden Agriculture in Indonesia

  The Subsistence Strategies of the Kalimantan Kant

  • Michael R. Dove(Author)
  • 2012(Publication Date)
  • De Gruyter Mouton

    (Publisher)

  Chapter Four Burning The burning of the swidden serves several different purposes. The most important of these is conversion to ash of the slashed and felled vegetation, as well as the layer of humus on the forest floor. It is this ash that largely will sustain the crops later planted in the swidden. A second purpose of burning the swidden is to eliminate obstructions to later work therein. If not burned or if not burned well, the slashed brush and felled timber will hamper the workers who later plant, weed and harvest the swidden. Indeed, the Kantu' cite this as one of the main reasons for not planting any part of a swidden that does not burn well. Unburned brush and timber also pose a threat to the rice plants if the swidden ever is flooded. The third and final purpose of the burn is to kill or retard the growth of any vegetation still living in the swidden, which would otherwise compete with the swidden crops for scarce sunlight, moisture and nutrients. For example, a good burn will kill trees that were deemed too difficult to fell. A good burn also will kill (or at least retard the growth of) the sprouting trunks of felled trees, which otherwise must be slashed during the weeding phase. Finally, a good burn will kill many of the germinating seeds whose growth has been stimulated by removal of the forest canopy. Following a poor burn, the Kantu' say, the growth of pioneering weeds - which must be weeded out before the rice harvest in many cases - is much more rapid. This can be seen within a single swid-den: thirteen days after swidden #55 was burned, seed-lings ten to thirty centimeters in height were present in unburned portions of the swidden, but no seedlings at all were present in the portions that burned well. The several purposes served by the burn are of singular importance in the swidden cycle. Indeed, the Kantu' say that the success or failure of the rice crop is determined chiefly by the success or failure of the burn.

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  Agroecosystem Sustainability

  Developing Practical Strategies

  • Stephen R. Gliessman(Author)
  • 2000(Publication Date)
  • CRC Press

    (Publisher)

  The slash mulch system in the New World was described by early Spanish explorers. Our best documentation of slash mulch systems historically comes from the neotropics, where some of the systems are still in place. Historically the slash mulch system produced beans, maize, sorghum, rice, sugar cane, bananas, and root crops. Slash mulch systems have been described by anthropologists in Africa and IMPROVING AGROECOSYSTEM SUSTAINABILITY USING ORGANIC MULCH 69 Asia, where maize, beans, sweet potatoes, sesame, sorghum, rice, bananas, and taro were grown (for review of the literature see Thurston, 1997). Unlike many traditional systems, the slash mulch system is still in wide use in Latin America; today it is particularly relevant to Costa Rican bean production (where the system is called frijol tapado ). Bean acreage in the slash mulch system has not changed much over the last 20 years and still accounts for 30 to 40% of Costa Rican bean production, 60% of which is sold off the farm (Rosemeyer, 1995). Another system, the unmulched espequeado , has been promoted in Costa Rica as a high input, modern system. In the espequeado system, the land is cleared, beans are planted with a digging stick, and fertilizers and pesticides are applied (Rosemeyer and Gliessman, 1992). The slash mulch system is traditionally managed as follows. After about two years of fallow and the selection of an appropriate area based on vegetation, paths are cut in the undergrowth with a machete and seed is broadcast. Then the vegetation between the paths is chopped down and cut up on the ground to form a mulch layer 5 to 20 cm thick. Although this vegetation is often described as containing weeds, it is actually the secondary growth of herbaceous plants and trees. The materials are not weeds in the sense of that weeds represent undesired vegetation. The vegetation is desired for its mulching properties and is not from the common European species found in intensively cropped systems in the New World.

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