Presentation on theme: "Agricultural Landscapes I HO Pui-sing. Contents Introduction Agricultural Systems Impacts of Urbanization and Industrialization on Agricultural Landscapes."— Presentation transcript:
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, combined- harvesters and chemicals
Ecological system – Energy Flow Energy efficiency Energy Yield Ratio=energy output / energy input Source of EnergyExampleEnergy Yield Ratio High Energy system Solar energy, Vast inputs of fossil fuels Farms in USA, Western Europe …. 0.38:1 Low Medium Energy system Energy input from the sun, wind & use of animals Wet rice cultivation in Asia 4:1 Medium Low Energy System Solar energy mostlyShifting cultivation in SE Asia, Pastoral nomads 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 5.7 o C Different crops need different accumulated temperature (Wheat needs a threshold temperature 5 o C 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 co- operative 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 farming.
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 , Avian flu Event , SAR Event ….) There are few fish ponds, horticultural gardens and very few farms (organic farmlands, leisure farmlands) exist in H.K. now.