A-Level地理-发达国家的农业Agriculture in MEDCs
2018-06-14 12:06 三立在线
摘要：Revision: Agriculture in MEDCs Agriculture in MEDCs is predominantly commercial as want to maximize profits. Farms are large, mechanised and technologically advanced to allow economies of scale. There is also very high diversity in MEDCs. There has been a lot of modernization in farming towards rationalization and increase in productivity (Organized Industrial Agriculture.) Therefore there are now: Larger farms specialization leads to monoculture
Revision: Agriculture in MEDCs
Agriculture in MEDCs is predominantly commercial as want to maximize profits。 Farms are large, mechanised and technologically advanced to allow economies of scale。 There is also very high diversity in MEDCs。
There has been a lot of modernization in farming towards rationalization and increase in productivity (Organized Industrial Agriculture。) Therefore there are now:
Larger farms – specialization leads to monoculture.
Greater mechanization – USA & Canada bread basket of the world。
Greater use of fertilizers, pesticides etc.
Increased productivity due to:
Reasons for the intensification of farming
Most changes to farming in the 20th century have led to increased intensification & output. Intensification leads to pressures on the land and a specialization in products. Farms have steadily increased in size to allow economies of scale. Technology has helped this with the drainage of land, mechanization, irrigation etc. Also new varieties of seeds (HYVs) have been developed that are suited to British conditions. Winter wheat is used to give higher yields and Friesian cows give higher milk yields. Chemical fertilizers & pesticides are now also extensively used.
Farming has become more of a business leading to the development of the agribusiness:
Organizations and companies e.g. Birdseye have bought up farms to supply them, especially in productive lowlands e.g. E Anglia. These companies control all stages of production. In California, 2 companies produce 2/3 of all fruit & vegetables. Machinery has taken over from people & so jobs have been lost. This is now having an increasing effect in LEDCs.
Consequences of the Intensification of farming
EU subsidies promote environmental damage:
Cultivation extended to previously unsuitable areas such as Chalk downlands previously used for sheep farming. Young cereal crops planted in rows with bare soil in between to stop competition causes soil erosion – rills & gullies form. Made worse by machinery compacting the soil.
Prairie-ization - Hedges ripped out to create large fields – more efficient。 This increases soil erosion as wind blows the topsoil off。 The biodiversity of the area is also reduced as hedges provide a "wildlife reservoir" and are ecologically valuable。 Similarly there is a loss of woodland and pond habitat, as land is needed。
Eutrophication – Use of fertilizer (e。g。 NPK) leads to nitrates leaking into rivers causing algae bloom, Blue Baby Syndrome & cancer。 The washing off of the fertilizers also loses the farmer money。 The use of biocides also damages the environment e。g。 DDT。 The indiscriminate spraying of pesticides causes environmental damage。 Pests may build up a resistance to pesticides (super-pests) so it is better to use biological pest control。
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