Presentation on theme: "RURAL GEOGRAPHY Global Agricultural Systems. Agriculture Part of a complex system Operates at different levels of intensity in different parts of the."— Presentation transcript:
Agriculture Part of a complex system Operates at different levels of intensity in different parts of the world, and for different purposes Interaction of hydrosphere, atmosphere and biosphere, human and economic factors Has changed, and continues to change, as a result of developing technologies, especially the Green Revolution of the latter 20 th century Different types of agriculture have distinctive human landscape with its own pattern of settlement and communications; characteristic population density, structure and distribution.
GMTs Analysis of: Land use data and crop yield in map and diagrammatic form The results of farm surveys Annotation of field sketches and photographs of rural landscapes
Types of Agriculture Arable farming = crops –Most favourable areas in terms of relief, soil and climate. Pastoral farming = livestock –Response to difficult conditions in terms of height, slope and rainfall (both high and low) Mixed farming = crops + livestock
Types of Agriculture Subsistence farming = to feed local people without having a surplus –May lack capital and modern technology, but methods involve high degree of skill and ingenuity. 2.Commercial farming = to produce surplus for sale, either locally or distant –Capital intensive, dependent upon technology (mechanical, chemical + biological) and dependent on efficient transport links
Types of Agriculture Shifting cultivation (usually subsistence) –Low population density, therefore low demand for food; must be plenty of land available to allow people to move cultivated plots and settlements as necessary. Sedentary cultivation (usually small/ large scale commercial) –Permanent cultivated land and settlements
Types of Agriculture Intensive agriculture –High level of capital and artificial inputs (fertiliser, pesticides) resulting in high yields –e.g. battery poultry units/ dairy farming Extensive agriculture –Low level of capital and artificial inputs resulting in lower yield, but often involving large areas of farmed land. –e.g.large grain farm/ cattle ranching
Farm System 1INPUTS Physical Human/ cultural Economic/ political 2DECISIONS 3OUTPUTS Profit Stability Loss Lack of investment and stagnation
Question CORE HIGHER PAGE 255QUESTION 1 Diagram 8.5 is on page 233
Example of Extensive Subsistence Agriculture Found in areas with low population densities Humid tropics of South America, Africa and South East Asia Globally supports as many as 300 million people
Shifting Cultivation Characteristics (summarise in spider diagram) Settlement usually small and temporary Settlement lifespan is determined by the rate of decline in soil fertility and the productivity of the cultivated clearings around it Remote areas, and thinly populated areas of Amazon Basin Low population densities because of Isolation, poor communications and lack of economic development The inability of shifting cultivation to support a larger population; once the population reaches its threshold a small “break off” group will set up a new group
Shifting cultivation and low population densities
Shifting Cultivation Characteristics Core Higher, Page 242, Diagram 8.18 Draw and annotate field sketch of typical single house settlement Remember the title
Shifting Cultivation Extensive system – large land area available, low input of labour and low output Year long growing season helps cultivation –(Fig 8.21, Page 243) “gardens” of cultivated land around traditional single house Crops include manioc, bananas, yams (high carbohydrate) Sustainable form of agriculture, although it requires large amounts of land to make it possible. Is it sustainable globally when it involves the destruction of primary rainforest?? Best cultivated with less than 8 crops for 2yrs then left fallow (unused) for 10yrs during which time it will revert to secondary rainforest and the soils recover fertility. If no new land is available, or the population increases, the “garden” can be continuously cultivated but requires frequent applications of fertiliser.
Shifting Cultivation The Clearing Process Un-cleared rainforest floor has thick humus layer with rapid organic decomposition Slash and burn cultivation – vegetation slashed and cleared using machetes, then burned to finally clear area and also to enrich soil by input of phosphorus and potassium from burning the vegetation. However, the soils (latisols) are basically of low fertility and when rainforest is cleared the soils are left open to high rainfall Nutrients are leached down through the soils Soil fertility is reduced Productivity is reduced Garden is abandoned New clearing is made in a new part of the forest and the process begins again.
Abandoned clearingCurrent clearing (reverting to secondary rainforest) Virgin Rainforest
Pressure on Shifting Cultivation in The Amazon 1.Figure 8.25, page 245 Discuss sustainability Question 11, page 256, 2.Read page 245 Create a spider diagram detailing the main threats and pressures on traditional shifting cultivation practices
Pressure on Shifting Cultivation in The Amazon Population pressure in, for example, NE Brazil results in immigration by “colonists” on a large scale to take up holdings along new roads within the Amazon Basin. These colonists come from different environments and lack the knowledge of the native people in farming in a sustainable way so ever increasing amounts of land need to be cleared Extensive areas of rainforest cleared for large scale cattle ranching to provide beef for huge urban population of SE Brazil Extensive areas of rainforest cleared for mineral (iron ore, gold, copper, bauxite) and timber resource exploitation Extensive areas of rainforest cleared for large scale Hydro Electric schemes to provide power eg Tucuri Dam Project, Brazil Clear felling of large areas of rainforest for heavily fertilised, single crop agriculture rather than sustainable “gardens” of traditional shifting cultivation. As soil productivity decreases more and more land has to be cleared.
RICE CULTIVATION IN KEDAH STATE, MALAYSIA Example of Intensive Peasant Agriculture Very high population densities (low death rate, high life expectancy) Humid tropics of South East Asia Traditionally subsistence agriculture but recent changes have led to increasing yields and have changed system to commercial agriculture Small holdings as land is at a premium, only one-two hectares often in scattered plots often some distance away from kampoongs (villages either along embankments or on islands within padis) (Figure 8.28, page 248)
RICE CULTIVATION IN KEDAH STATE, MALAYSIA REQUIREMENTS FOR CULTIVATION All year round growing season – equatorial climate with monsoon influence provides a wet season in which rice grows and a dry season in which it ripens and can be harvested. High temperatures and small temperature range (difference between highest and lowest temperature) (Figure 8.30, Page 250) Flooded padi fields or sawahs to grow rice Dry months of January and February allow padi fields to dry out and rice to ripen Irrigation from Muda Irrigation Project allows padi fields to be flooded during dry season and allows two rice crops per year to be grown under more intensive modern cultivation.
CLIMATE OF TRADITIONAL RICE CULTIVATION Traditional one crop per year cultivation – New rice breeds allow two crops per year nowdadays
Transplanting rice plants by hand into flooded padi fields Bunds – small raised earth walls – between padis
Transplanting rice plants by hand into flooded padi fields
Commercial Rice Cultivation Recent changes in cultivation have increased yield and rice cultivation is now and example of Intensive Peasant Commercial Agriculture. Using the information on Page 249 + 250 of Core Higher 1.Summarise these changes in a spider diagram or as bullet points 2.Summarise the effects of these changes on (i) the farming in Kedah and (ii) the lives of the rice farmers
The Green Revolution Began in 1960 as a result of Research carried out at the International Rice Research Institute (I.R.R.I.) in the Philippines. Involved the development and use of short-stem (do not get damaged or flattened), high yielding cereals (rice, maize, wheat) with short growing seasons which enables two crops to be grown per year. Early success with IR8 rice, which has since been further improved. Increased and improved mechanisation Increased and improved irrigation and drainage Increased use of agro-chemicals = Increased yields
The Green Revolution Core Higher Page 254 Figure 8.38 What were the main (i) aims and (ii) results of the recent rice breeding program at the I.R.R.I 2 In a table, summarise the main advantages (successes) and disadvantages (failures) of the Green Revolution, in terms of productivity, equability and sustainability.
The Green Revolution The future Green Revolution must be (i)Sustainable (ii)Accessible to all needy people in the Developing World, and (iii)Environmentally friendly Sustainability can be achieved by a variety of agricultural technologies Using Figure 8.39 on Page 255 detail some of these technologies
GRAIN FARMING ON NORTH AMERICAN PRAIRIES Example of Extensive Commercial Farming Extends from northern Mexico through midwestern USA and into Canada (Manitoba, Saskatchewan and Alberta) As you move northwards the growing season gets shorter (300 in the south to less than 100 days in Canadian Prairies) Rainfall decreases westwards Farm size increases westwards, because the climate becomes more difficult so more land has to be farmed in order to maintain yields. Crops from south to north are : cotton; winter wheat; maize; spring wheat in the north
Grain Farming on North American Prairies Very geometric settlement/ landscape pattern Major immigration 120yrs ago and settlers were given a 64 hectare plot. At this time agriculture was intensive, however now farms have been amalgamated into larger units and Plains agriculture is now extensive.
Grain Farming on North American Prairies Marginal climate for farming because of short growing season and low variable annual rainfall. Droughts are common Very cold winters, temps of -15 to -20ºC not uncommon. Irrigation is necessary By early 20 th Century many farms had failed
Grain Farming on North American Prairies Early 20 th Century Farm sizes had increased – extensive agriculture Improved agricultural technologies Steel plough, disc harrow, reaper, binder Pumps and windmills made irrigation easier as water was pumped from aquifers (underground water reserves within permeable rocks) New strains of fast growing spring wheat were imported from Steppes of Russia (Russian wheat growing plains)