Main learning outcomes: you should…• be able to describe the main features of this type of farming, including the crops grown, the level of technology used and the main activities throughout the year.• be able to describe and explain the settlement pattern and the population density.• be familiar with the changes occurring in areas of shifting cultivation and the impact of these changes on the people and the landscape.
INTRODUCTION One of the most primitive form of farming found on the earth, Shifting Agriculture still supports over 300 thousand people. This type of farming has probably existed for over 10,000 years and was once very widespread – even found in stone-age Europe.Largely replaced by sedentary or fixed farming, it is now in danger of disappearing altogether. It is now found mainly in equatorial rainforest areas.
Tropic of Amazon Centra Indonesia Cancer Basin l Africa and PNG.EquatorTropic ofCapricorn Global Distribution of Shifting Cultivation Global Distribution of Shifting Cultivation
Around the World…• Shifting cultivation is also known as:-• Slash and Burn;or• Ladang (Malaysia)• Roca (Brazil);• Masole (Congo)• Milpa (Mexico)• This presentation looks at examples from the Amazon Basin and Papua New Guinea
Types of Shifting Cultivation• Shifting Cultivation proper;• Permanent village, shifting cultivated areas;• Rotational bush fallowing.
Shifting Cultivation proper…• Shifting Cultivation in its purest form, clearings are made in the forest, used for two to five years to grow food, then abandoned and a new clearing created. This is repeated, with the village eventually returning to the original site after 25 years or more – or maybe never.• Such frequent moves are necessary because the soil quickly loses its fertility and crops will start to fail after only a few years.• Abandoned clearings will be reclaimed by the forest and gradually the soil fertility will recover.
…permanent village, shifting cultivation• This variation is probably more common, particularly in Africa.• In this system, the village remains in one place and the farmed clearing is changed every few years. The old clearing is left “fallow” or rested.• This system is found where the population is permanent, the total land available may be less and where population densities may be higher.
…rotational bush fallowing• As population pressure increases and the amount of available land decreases, the land around the village is used continuously.• This often leads to rapid exhaustion of the soil, particularly if animal manure or other fertilisers are not used.
…rotational bush fallowing Continuously cultivated area around village 1 6 2 Outer clearings farmed in rotation Village5 3 4
Population Density and SettlementPattern Because of the large The settlement required area of forest pattern with is dispersed or all of these moves, scattered. the overall population density is very low – often less than 1 person per sq.km.
The Climate• Most shifting cultivation is found in areas of Equatorial climate.• Here the sun is overhead, or almost overhead for the whole year, bringing consistently high daily temperatures.• The typical daily weather pattern is of increasing humidity and heavy afternoon thunderstorms, caused by convectional rain.
Climate Graph for Iquitos, Amazon Basin, Peru (3½ ºS) Climate Graph for Iquitos, Amazon Basin, Peru (3½ ºS) 350 30 300 25 250 20 This combination of Rainfall is abundant all Temperature is high allRainfall (mm) 200 Temp.ºC year, with most areasand moisture warmth year – above 25º C – and 15 receiving creates twelve monthsvery little from around varies 150 2000mm annually - growingmonth to month. of perfect about the same as the for plants – conditions 10 100 west of Scotland! Rainforest is the result 5 50 0 0 J F M A M J JL A S O N D Months
Main features…• This is subsistence farming – only providing enough for the group, with little or nothing left to sell.• It is extensive farming i.e. it covers a large area of land;• The technology level is very low – all work is done by hand, with only a few basic tools.• This type of farming is sustainable or eco-friendly – it does no lasting harm to the forest environment, as long as the clearings are given enough time to recover their fertility.
In the top diagram the fallow period is long enough to allow the soil torecover its nutrients: in the lower one the land is returned to farming too soon and it quickly loses its fertility.
A Here we see a communal Yanomami house (Maloca) in a rainforest clearing…
Such settlements usually house about 20 – 100 people.Many of thesegroups have had nocontact with themodern world.
A Boro tribe Maloca A Guarani tribe versionThe design varies between different tribal groups…
In Papua New Guinea a house is built in a few hours…The final roofcovering goeson…
Two members of the Mati tribe (cat people)…only recently “discovered” by the outside world.
Although they may look a bit primitive to us, these people are able to live in a very tough environment, where soft westerners like us wouldn’t last long.…some Mati boys go toschool - part of agovernment developmentprogramme for thenative Amerindiantribes.
Slash and Burn - first the forest is cleared – by hand…
Who needs matches? … making fire with two sticks …
..the cut down trees are allowed to dry for threemonths or so, then burned, in small, controlled fires.
Ground clearance is very hard work, so many stumps, branches and roots are left.
The burned wood adds ash (a natural fertiliser) to the soil.
However, the torrential rains cause rapid leachingUnless the land is left fallow (rested) to recover of the already poor soils, washing vital mineralsthese nutrients, it will be permanently degraded. out of the soil and reducing its fertility. This iswhy the clearings are only used for a few years. LEACHING by rain.
In this Chagra,a garden rather than a field, maize seeds are being plantedamongst Sweet Potato (Papua New Guinea).
The plants grow quickly in the warm, wet climate.
Taro, similar to Sweet potato, nearly ready for lifting.Taro, similar to Sweet potato, nearly ready for lifting.
Manioc – probably the single most important crop……its rootsprovidingcarbohydrate-rich Cassavaflour (Tapioca).
Simple fences to keep out wild and domestic animals…
Maize (corn) may be grown where the soils are richer.Papaya and otherfruits form animportant part ofthe diet.
Sugar cane may sweeten an otherwise bland diet.Banana providesimportant minerals suchas Potassium
Other crops may include… • Yams • Tobacco • Coca • Mangoes • BeansDomesticated animals such as pigs and chickens may alsobe kept.
Meat is usually hunted in the forest … monkey, tapir..The forest also supplies thepeople with fruit, berries,medicines, poisons anddrugs...and, of course, fishfrom the rivers addimportant protein.
After a few years, the crops start to fail andthe clearing is abandoned – to be reclaimed by the forest.
Changes 1• Shifting cultivation is in danger of disappearing;• This is due to destruction of large areas of the rainforest on which this system depends – the area available is rapidly shrinking;• This is caused by logging companies, cattle ranchers, gold, diamond and other mineral hunters & miners, HEP schemes, road building e.g. Trans Amazon highway and new settlers moving in to the forest;• Population growth is also putting additional strain on this way of life – particularly in west Africa.
Changes 2• Some Indian groups have been forced into reservations or retreated into more remote areas deep in the forest;• many tribes have suffered from Culture Shock;• There has been violence and intimidation against these tribes, with many thousands killed by new settlers;• Thousands have also died due to lack of immunity to “western” diseases such as measles;• There has been serious water pollution by gold mining, which uses toxic substances such as mercury. This has caused poisoning of rivers and people.
In Brazil, forexample, thebuilding of theTrans AmazonianHighway hasopened up thevirgin rainforest tosettlement andexploitation, oftenwith disastrousconsequences forthe shiftingcultivators.
Massive deforestation is removing the habitaton which shifting cultivation depends, as here in Brazil.
Huge fires now destroy enormous areas in a few hours.Shifting cultivation isabandoned and replaced bylarge, often foreign ownedschemes.
…such as the Jari Project in the 70s and 80s, with itsforestry plantations, cattle ranches, towns and railway lines.
Thousands of garimpeiros, or gold miners,devastate an areaof rainforest in adesperate search for gold.
Review of Main points• Shifting Cultivation is also known as slash and burn;• It is found mostly in the equatorial rainforest areas of the world e.g. Amazon, Congo, PNG.• It has several versions, including bush fallowing;• It is low technology;• It supports a very low population density;• Its settlement pattern is dispersed;• It is subsistence farming, with little surplus;• It is under threat due to a combination of outside influences. Detailed knowledge of these forces of change is essential.
Important Terms • Slash and burn • Ash for fertiliser • Subsistence farming • Maloca - house • Chagra - garden• Manioc, Sweet Potatoes, Banana • Leaching of soil • Fallow period • Eco-friendly / sustainable