Shifting Agriculture 1

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- RURAL GEOGRAPHY SHIFTING CULTIVATION
Title
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 million 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
Cancer
Amazon
Basin
Centra
l Africa
Indonesia
and PNG.
Equator
Tropic of
Capricorn
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…
• In 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.
…Shifting village and cultivation
…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.
…permanent village: shifting cultivation
1
2
6
Village
3
5
4
…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
Outer clearings
farmed in rotation
2
6
Village
3
5
4
Population Density and Settlement Pattern
Because of the large area of
The settlement
pattern
forest
required with
all is
of
dispersed
or the
scattered.
these
moves,
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)
350
30
300
25
250
This combination
of
Rainfall is abundant
all
Temperature
is high all
warmth
year, with most
areas and moisture
year – above 25º C – and
receiving creates
around twelve months
varies very little from
2000mm annually
- growingmonth to month.
of perfect
about the same
as the for plants –
conditions
west of Scotland!
Rainforest is the result
200
150
100
15
10
5
50
0
0
J
F
M
A
M
J
JL
Months
A
S
O
N
D
Temp.ºC
Rainfall (mm)
20
The farming landscape and
the people…
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
to recover 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 these
groups have had no
contact with the
modern world.
A Boro tribe Maloca
A Guarani tribe version
The design varies between different tribal groups…
In Papua New
Guinea a house is
built in a few
hours…
The final roof
covering goes
on…
Inside, the houses are extremely basic.
Yanomami – one of the Amazon hunter gatherer
tribes who also practice shifting cultivation.
A Yanomami family in their Maloca.
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 to
school - part of a
government
development
programme for the
native Amerindian
tribes.
Main activities…
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 three
months 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,
theland
torrential
rains cause
rapid
leaching
Unless the
is left fallow
(rested)
to recover
of
the
already
poor
soils,
washing
vital
minerals
these nutrients, it will be permanently degraded.
out of the soil and reducing its fertility. This is why
the clearings are only used for a few years.
LEACHING by rain.
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