Transcript Agricultural Landscapes

Agricultural Landscapes I
HO Pui-sing
Contents
Introduction
Agricultural Systems
Impacts of Urbanization and Industrialization
on Agricultural Landscapes
Introduction
Importance of Agriculture
The Landscapes of Medium Human Impact
Film 1
Film 2
Importance of Agriculture
Agriculture refers to the raising of crops and
livestock by man to produce useful commodities.
It is a economic activity and the most basic of all.
Food supply, raw materials for industry
2/3 people are engaged in various forms of
agriculture all over the world.
It is a way of life.
Agricultural land occupies 33% of the earth’s land
surface. (11% cropland, 22% pasture)
Farms products are very important elements in
world trade. (many countries cannot produce
enough food for their own needs)
Influence of the Environment
Physical factors set outer limits to farming
(temperature, rainfall, landforms, soil
types,growing season….)
Physical factors determine the outer
boundaries for the production of particular
crops or animals and the areas of optimum
yields. (rice, wheat, sugar cane,
dairying, …….)
Impacts on the Environment
Farmer is constantly modifying the natural
environment.
Clear the forest, planting, plough land, sow crops, adding
fertilizers…..
New landscape
Use a unsuitable farming method in the environment
and causes serious consequences
Over-cropping and over-grazing cause soil erosion
Using chemical fertilizers and pesticides gain
enormous benefits and environment pollution
(Eutrophication)
Impacts on the Environment cont’d
Man is increasingly trying various methods of
overcoming the physical environment
Modified soil: terrace, wet lowlands drained,
coastlands reclaimed, adding chemicals
(fertilizers, pesticides, weedicides)
New varieties of plants and animals
Requirement: large input of capital and
labour (extremely high cost)
Developed countries can lessen to some
extent the influence of physical environment.
Agricultural systems
Human organized system
Ecological system
Economic system
Classification of World Agriculture
Physical components affecting
agriculture
Cultural components affecting
agriculture
Human organized system
Agriculture is a organized system is which
man applies his skills to the natural
environment for economic gain.
Inputs (organized natural and human inputs)
Natural elements
• Landforms, climate, soil, ….
Human elements
• Level of civilization, social organization, technological
and management skills, political organization
Human organized system - cont’d
Outputs
Crops and animal products
Arable farming
Plant crops: rice, wheat, rubber,…..
Livestock farming
Animal products: meat, wool, milk,…..
(Herding, grazing, ranching, pastoralism)
Mixed farming
Both plant and animal products
Eg. Australia’s wheat-sheep farming
Human organized system – cont’d
Man-land combinations vary considerably
from place to place and forms various
agricultural systems
Commercial agricultural system
Human inputs > natural inputs
For food, manufacturing and urban
Developed countries
Subsistence agricultural system
Natural inputs > human inputs
For local tribal or village communities
Developing countries
Human organized system – cont’d
Dynamics
Man can alter the human inputs and natural
inputs.
Human inputs:
• cultural inputs, fertilizers, pesticides
His activities will modify the natural
environment (natural inputs)
• Conscious:irrigation, greenhouse,….
• Unconscious: climate changes
Ecological system
Farm is a manipulated ecosystem
For yields (desired products)
Provide the most favourable conditions for
the plants and animals he wishes to produce.
Ecological system – cont’d
Ecological system – Energy Flow
Natural ecosystem
Only source of energy from the sun
Living plant tissues use up about 0.02% of the total
energy input
Energy transfer:
• Start from photosynthesis and passed along food chains,
released in the form of heat to environment
Agricultural ecosystem
Energy sources: sun + various energy inputs
Subsistence farming system: animate energy
Commercial farming system: fossil fuel energy
Ecological system - Energy Flow
Energy from human environment greatly
depend on the culture of societies
Developing countries
Simple hand tools (shifting cultivators)
Developed countries
Petrol oil for vehicles, tractors, combinedharvesters and chemicals
Ecological system – Energy Flow
Energy efficiency
Energy Yield Ratio=energy output / energy input
Source of Energy
High Energy
system
Example
Solar energy, Vast
Farms in USA,
inputs of fossil fuels Western Europe….
Medium Energy Energy input from
Wet rice
system
the sun, wind & use cultivation in Asia
of animals
Low Energy
System
Solar energy mostly Shifting cultivation
in SE Asia,
Pastoral nomads
Energy Yield
Ratio
0.38:1
Low
4:1
Medium
16:1
High
Ecological system – Nutrient Cycle
Natural
Nutrients circulate within the ecosystem.
Nutrients are replaced again and again within
different parts of the ecosystem.
Agricultural system
Nutrients may be removed entirely by prolonged
cropping without compensating fertilizer input.
Nutrients may be heavily subsidized by input of
chemical fertilizers.
Nutrients can be unavailable or accumulate to
toxic level.
Ecological system - Stability
Natural
Solar energy drive energy flow and nutrients cycle.
Complex ecological linkages with a great variety of plants
and animal species.(biodiversity)
It is self-maintained and stable.
Agricultural system
Energy flow and nutrients cycle are drive by solar energy
and human energy inputs
Fewer crops and animals or even monoculture
It is maintained by much human effort so it is unstable
comparatively.
Economic system
Inputs as capital and human effort
Investment (inputs)
• Form of money
• Form of labour
Outputs as financial gain
Farmers need to make decision about how
much they are going to invest and in what
aspects they are going to invest.
Economic system – decision making
Key questions?
What to produce?
How much to produce?
How to produce?
How much to invest?
What to hire or lease?
How much to hire or lease?
Where and how to buy?
Where and how to sell?
Economic system – decision making
Differences in land use, cropping, use of biological
inputs, total outputs and farming methods…etc. are the
result of decision by farmers.
Agricultural patterns are the sum of total millions of
individual decisions taken by farmers.
Decision making is a process which is influenced by
Behavioural elements
Chance elements
Perception level of the decision makers
• Personal background (social, cultural, educational..)
• Information and ability
• Past experience
Perception of the environment will affect the decision
they make. But the final goal is profit satisfaction.
Economic system – decision making
Decisions result in action which may result in
land use patterns, wealth or poverty.
Wealth
economic surplus
innovation
Poverty stagnation
Economic system – decision making
Papua New Guinea
Subsistence economy
Farmers
Minimum investment
(human and cultural
inputs)
For tribal or village
consumption
Localize
Response to natural
conditions
Australia
Commercial economy
Entrepreneurs
Heavy investment (human
and cultural inputs)
For sale (foodstuff,
industry, urban)
Globalize
Response to markets
Economic system – decision making
We have general assumption that all farmers aim at
maximizing their outputs.
In fact, they very often do not
Reasons:
They haven’t knowledge to make the best use of land
They haven’t enough information and ability to use info.
They cannot afford fertilizers or machinery
Social customs may work against improvement
Personal characteristics
• Farmers are satisfiers
• Farmers may be conservative and consider a low degree of risk
• Farmers don’t want the extra work and they want to have more
leisure time.
• Others
Classification of World Agriculture
Arable farming: Growing crops
Pastoral farming: Rearing animals
Mixed farming: Growing crops and rearing animals
Commercial farming: For sale and exchange
Subsistence farming: For farmer’s own family
Cash-cropping: Growing cash-crops
Large-scale farming: Undertake on large farms
Small-scale farming: undertake on small farms
Intensive and Extensive farming:
Refer to the amount of combined labour and capital inputs
per unit of area farmland
Classification of World Agriculture
Intensive Farming
High volume of inputs per
hectare (both natural and
human)
High man-land ratio
High density of rural
population
Small farmland or land is
very expensive
Farmland close to market
Large output per hectare
Eg. SE Asia, China, Japan
Netherlands, New Zealand
Extensive Farming
Low volume of inputs per
hectare (both natural
and human)
Low man-land ratio
Low density of rural
population
Farmland is plentiful or
land is cheap
Remote to markets
Small output per hectare
Eg. N. American and
Australia
Physical components affecting agriculture
Physical environment affects the location and
intensity of farming system
It may limit the range of farming systems that
can be carried out at a given site.
Physical components
Climate:
• Precipitation, snow, temperature, frost, wind, light and
cloud cover
Relief:
Soil
Climate - precipitation
Annual total rainfall: It determines types of crops
>2000mm (rice, rubber..)
400~800mm (wheat)
Seasonal distribution: It determines types of crops
Rice (heavy rain for quick growth, but dry season for
harvesting)
Excess water
soil erosion
Heavy rain or flood
wash away young seedlings
Waterlogged soil
damages plant roots
Deficient rain or drought seasons need irrigation
and other forms of water supply
Climate - temperature
It determines various type of crops from equatorial (eg. Rice
and rubber) to cool temperate regions (eg. Sugar beet)
Germination and ripening of seeds require at least 5.7oC
Different crops need different accumulated temperature
(Wheat needs a threshold temperature 5oC for 1300 days)
Each type of crop has its own hot and cold limit
Frost is especially damaging for vegetables and fruit
Frost free days (growing days between last spring frost and the first
winter frost
Different crops need different frost free days
•
•
•
•
Spring wheat: 90 days
Corn: 150 days
Cotton: 200 days
Rubber: hot climate for all year
Climate – snow and light
Snow:
Light snow cover can protects the soil from erosion by
wind and rain.
It has insulating effects for some crops (winter wheat)
Spring thaw gives moisture to soil
Light:
Different crops need different amount of light for
photosynthesis
Sunlight is particularly significant for fruit ripening
Low humidity enable drying of fruit
Some tropical crops (coffee) require high temperature but
cannot grow under direct strong sunlight. Then cover
crops (banana) are planted to give shade.
Climate - Wind
Wind erosion is severe in semi-arid and arid
regions
Typhoons bring serious damages to crops
Constant strong winds make the crops difficult to
get hold of soil.
Local winds bring sudden change in temperature
and humidity.
Light wind helps pollination and seed dispersion
Light wind helps to lower relative humidity and
increase transpiration
Relief
Temperate regions: lowland is suitable for crops
growing for too short growing season in Mts.
Tropical regions: the best farming areas are in
upland for too hot and wet in lowland.
Aspect:
Affect temperature and water availability
Slope:
Too steep cannot cultivated
Tree crops and tea can be grown on hillside
Paddy, wheat and sugar should be grown in lowland.
Relief directly and indirectly affects other factors
(soil and climate)
Soil
Different soils support different crops
Rice: clay with much water
Tea: acid soil and well-drained
Sugar: very fertile soil
Sweet potato and yam: poor soil is OK.
Application of fertilizer (natural manure or
artificial) would change the soil water,
texture, chemical composition and fertility
Cultural components affecting agriculture
Socio-economic environment may
determines the possible farming system and
the input intensity.
Cultural components
Transport
Capital
Market
Labour
Technology
Social Factors
Transport
Transport networks link up farm and market
Farm products
market (cities)
Cities (machines, artificial fertilizers)
farm
Transport cost includes delivery cost, freight rate, insurance
and customs charges
Rural poverty of developing countries is partly the result of
insufficient linkage with the cities
Means of transport
Land, sea and air
Transport has greatly been improved in
Speed and facilities (packing and refrigeration)
The importance of transport is increasing with technology
improvement
Capital
Buy seeds, animals, farming machines,
fertilizers and other farming materials…..
Govt. loan (low interest rate) and grants may
help the productivity of farms
Lack of saving of farmer in developing
countries is one of the important drawback
for improvement
Capital in developed countries not only allows
farm improvement, but also saves them in
times of bad harvest.
Market
Places for selling farm products
Some advanced nations have carried out cooperative groups for processing and
marketing of their products. (eg. Sunkist)
Promoting sales,
standardize price and quality of products
Linkup with supermarket, large scale freezing
and canning factories
Labour
Different types of crops need different
amount of farm workers
Wheat: less workers
Tea: more workers
Some general farm work can be replaced by
machines
Harvesting period needs more labour
Farm workers are tight in thinly populated
rural area.
Technology
Modify the physical environment by
Irrigation on dry fields
To drain swamps
To build terraces on steep slopes
To produce artificial rain
New strains of plants (Bio-technology, Genetic
engineering)
Eg. Miracle rice, drought-resistant plants, cloning
Adding artificial fertilizers
Spraying insecticides
Mechanization
Technology is increasing the importance in
Social factor
Social attitudes of people, traditions, level of education…are
all determinants on farm production.
Some are encouraging but other are negative
Land tenure (land ownership)
Tenant farming
• A cash tenant farmer:
– Long lease will encourage further investment and cultivate more carefully
– Short lease will make him maximize profits by over-grazing and over-cropping,
which lead to soil erosion
• A share cropper: safeguard against fluctuating yield
Freehold ownership:
• Advantage: incentives to manage their farms efficiently
• Disadvantage: fragmentation of fields through inheritance law
State ownership (communist countries)
• Advantage: consolation of fields, mass team work
• Disadvantage: lack of private ownership
discourage incentive
Impacts of Urbanization and Industrialization on
Agricultural Landscapes
Impacts on agriculture production pattern
Agricultural land use patterns
Economic influences on agricultural location
Von Thunen Model
Sinclair Theory
Impacts on agriculture production pattern
Impacts of Urban Expansion
Loss of Farmland
The anticipation of urban expansion
Intensity of agricultural activities
Farm Size and land ownership
Case Study: Hong Kong
Impacts of Urban Expansion
Urbanization and industrialization
necessitate the expansion of urban
areas and an inevitable infringement
into the surrounding farmlands
Loss of Farmland
Especially good farmland in areas close
to the urbanized areas
Urbanization
Increase urban population
More houses, shops, factories, schools and
other public works….
UK’s Green Belt Policy for checking the
rapid expansion of urban sprawl.
Anticipation of urban expansion
Farmers within a few km of the city edge may have
a opportunity to sell their farmland at very high
prices
This will influence the intensity of farmland
Farmers are unlikely to start long-term improvements
Fewer investment and become more extensive
Insufficient labour force for intensive cropping
Part-time farmers rarely farm intensively and part-time
farming is very common.
Plant orchards or other perennial crops
Land is left idle for the building road, which cut off a
field from the main part of the farm.
Intensity of agricultural activities
More intensive agricultural activities may be found in the
large urban periphery.
Reasons
Large market for fresh and quality products of suburban orchards
and nurseries
Urban area provides fertilizers, machines and casual labourers,
which help to cut down costs of agricultural inputs.
Urban dwellers contribute to investment in agriculture.
Specialized and intensive farming systems can be found in
peri-urban regions
Products: high value products (fresh vegetables, fruits,
flowers, nursery plants, milk, fish, pigs and poultry……
Farm size and land ownership
In general, near the peri-urban
Farm size become smaller
Land is expensive
Few farmers can increase their holding
Part of the farm may be sold
Farming may be intensive (horticulture, pigs, poultry or
dairying)
Farming may be extensive even abandon
Relatively high proportion of tenants
Must be use case studies for specific examinations
Case Study – Hong Kong (1970s)
Urban population growth of Hong Kong
start from 1950 and the increase of
urban areas and satellite towns.
Tsuen Wan, Kwun Tong, Shatin, Tuen
Mun, Tai Po,……..
The impact of urbanization on farming
is very strong
Agricultural Zones in YL (1970s)
Changes on Farming (1970s)
Decrease of farmland and Increase of abandoned land along the hillside
Urbanization and industrialization (Construction of roads, new towns,….)
Swamps and fields were converted into residential areas
Young farmers were attracted to urban area for better jobs and high wages
(rural-urban migration)
Labour shortage in the remote areas especially
Increase of market gardening around the city core (Yuen Long) and
along roads. Pigs and poultry farming replace paddy and tree crops. On
the other hand, fish ponds were also increased – Intensive farming
Higher standard of living of urban people
Large demand for high quality of fresh crops.
Vegetables and flowers are more yields per year and more profitable.
More investment, mechanization and specialization
Improve transport system for export products to urban
Change on Farming (1980s to 90s)
Increase abandoned land around city core
and along highways.
Intensive farmlands became to extensive
farmlands, left fallow or even abandoned
Many farmlands near the city core and along
highways were converted to other land use
(cars repair, warehouses, residential….) or
ready for sale.
Farmland became more intensive further
away from the city core and the highways.
Change on Farming (21 Century --)
Basically, there are no real agriculture in Hong Kong.
Not only farmlands near the city core and along highways
were erased, but also farmlands in remote area were
abandoned, waiting for sale or even converted to
residential area.
Food stuffs import from outsides regions.
Prefect internal and external transportation networks.
Government Policies make against agricultural development
(Code of Practice - Livestock Waste Management - 1987, Avian
flu Event - 1997, SAR Event - 2002….)
There are few fish ponds, horticultural gardens and very
few farms (organic farmlands, leisure farmlands) exist in
H.K. now.
The End