Shifting cultivation

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Shifting cultivation, also known as swidden agriculture or slash-and-burn, currently supports between 300-500 million people worldwide. This cultivation is a way of life that is being considered outdated with the growing concern for nature conservation and protection of forests. Shifting cultivators are being looked upon as a major cause of tropical deforestation and world attention is focused on ‘slash-and-burn’ practices in the tropical region. Organizations such as World Bank, FAO and others have recommended agro-forestry, and other modes of permanent agriculture, as alternatives to shifting cultivation.

Upland farmers in many countries of SE Asian countries and in parts of Bhutan, NE India, Myanmar, and Chittagong Hill Tracts (CHT) are completely dependent for their sustenance and livelihood on shifting cultivation. Here too the Governments advocate switching to more settled agriculture practices.


[edit] What is Shifting Cultivation?

Under the system of shifting cultivation the cultivated areas are shifted with regularity and left fallow for long periods to allow soil fertility to recover. Cultivation is carried out in a minor portion of the land and the remaining left for various stages of re-growth. Cultivation is also done for short time periods and the fields left to recover, or fallowed, for a much longer period. Fields in established and stable shifting cultivation systems are cultivated and fallowed cyclically.

Shifting cultivation has over the years been dismissed as wasting natural resources and leaving those involved in a vicious poverty cycle.

[edit] Cultivation Stages

Broadly, shifting cultivation involves three stages:

  • Field Clearing -- A small patch of [rainforest] is selected for cultivation. The tribe involved slashes the natural vegetation to allow nutrients to be released as ash. This dissolves and is washed by rain and enters the soil where it works as natural fertilizers.
  • Growing of Crops -- A variety of food crops like rice, maize, cassava are grown on the land. The crops grow very quickly; some are ready to harvest after four to six months. After 2 or 3 years, due to deterioration in soil fertility, the yield of successive crops declines and weeds grow extensively.
  • Abandoning the Site -- In this stage the cultivators abandon the site and move the cultivation to a new one, where the process of clearing another patch of the rainforest is taken up. The tribe normally does not return to the former clearings for at least 50 years.

During this long period of abandonment there is regeneration in the rainforest which helps replenish the nutrient quality of both soils and vegetation following the restoration of the land’s fertility. As a result of this regeneration the soil is protected from erosion and the spread of weeds and pests is controlled.

Disposal Methods

Following the cultivation, some farmers use the “slash-and-burn” method as one element of their farming cycle while others employ land clearing without any burning. Some cultivators are purely migratory and do not use any cyclical method on a given plot.

[edit] Cultivated and Fallowed Periods

In shifting cultivation the cultivated period and fallowed period are critical to determine if the system suffers a net loss of nutrients over a period of time. Repeated net loss of nutrients with each cycle eventually results in degradation of resources, leading probably to irreversible exhaustion, unless special efforts are made to arrest it.

Prolonged cultivation leads to:

  • greater soil organic matter generation
  • cation-exchange -capacity reduction
  • nitrogen and phosphorus reduction

In a stable shifting cultivation system, the fallow is long enough for the natural vegetation to recover to the state that it was in before it was cleared, and for the soil to recover to the condition it was in before cropping began.

[edit] Who are Shifting Cultivators?

Social groups, usually tribes, have control over the land which is common property. Land is distributed to the designated families who carry out the cultivation themselves. Men usually clear the land and women carry out planting, cultivation and ‘marketing’.

In Africa, shifting cultivation is practiced by farmers throughout the humid zone. Unlike Sub-Saharan Africa, where everyone belongs to a tribe, in Asia and Latin America the long fallow shifting cultivators have traditionally been ethnic minorities with their own language, religion, values and, in some instances, crops.

[edit] Consequences of Nomadic Habits

The cultivators face the following consequences because of their nomadic habits:

  • Soil and forest resources are wasted by bush fires, erosion and other factors.
  • Cultivators are not induced to intensify their agriculture, nor motivated to carry out long-term improvements of their land.
  • Because he is required to move away from time to time, a cultivator is not able to accumulate any permanent material wealth.
  • As soil degradation and famine keep dispersing and re-dispersing the cultivators, the population density of the area does not grow
  • Without population growth urbanization does not take place and the cultivators are faced with no prospect of growth.

[edit] Criticism and Support

Shifting agriculture has frequently been attacked as unproductive, wasteful, primitive and exploitative. Shifting cultivators are blamed for widespread environmental degradation, destruction of much of the world’s tropical forests, atmospheric pollution and global climatic change. Moreover, the slash-and-burn agriculture is seen as a waste of land and timber, and a major reason for forest destruction.

But other schools of thought believe that shifting cultivation has been practiced all over the forested parts of the world at some stage of history. It has been applied in very different geographical, social and cultural settings, and this agricultural practice has not always led to an environmental impasse. In fact, many researchers today agree that shifting cultivation can be a sustainable farming system when well applied in favorable conditions.

[edit] Ecological Problems of Shifting Cultivation

With the demand for cultivation of land increasing, the cycle of cultivation followed by leaving land fallow has reduced from earlier 25–30 years to 2–3 years. Because of the prolonged periods earlier the land could get adequate time to return to natural condition. But with this reduced cycle of 2–3 years, the resilience of ecosystem has broken down resulting in increased deterioration of land.

[edit] Did You Know?

  • An estimated population exceeding 250 million people derive subsistence from the practice of shifting cultivation
  • Shifting cultivation survived from the Neolithic into the middle of the 20th century amidst the sweeping changes that occurred in Europe over that period.
  • The earliest written accounts of forest destruction in Southern Europe begin around 1000 BC in the histories of Homer, Thucydides and Plato and in Strabo’s Geography.
  • Unlike the conventional farmer who sits on a tractor, the swidden farmer is down on the ground examining every inch of the field, matching crop to soil and drainage.

[edit] Additional Information

  • Agro-forestry

[edit] References

  • Shifting Cultivation and Commercial Logging
  • Rain Forest
  • Ecological problems due to shifting cultivation
  • Shifting Cultivation
  • Sustainability in danger?
  • Shifting cultivation - FAO
  • Integral swidden