Presentation is loading. Please wait.

Presentation is loading. Please wait.

Agriculture and the Environment OCR A2 Options Environmental Biology.

Similar presentations


Presentation on theme: "Agriculture and the Environment OCR A2 Options Environmental Biology."— Presentation transcript:

1 Agriculture and the Environment OCR A2 Options Environmental Biology

2 Development of Farming in Britain 14, 000 y.a 14, 000 y.a domestication of dogs from semi-wild animals domestication of dogs from semi-wild animals 9,000 – 10,000 y.a 9,000 – 10,000 y.a domestication of cattle, sheep and goats domestication of cattle, sheep and goats gatherer-hunters gatherer-hunters 5,000 – 6,000 y.a 5,000 – 6,000 y.a Agriculture develops Agriculture develops lowland deforestation for crop growing lowland deforestation for crop growing

3 Deflected Successions Succession Succession the gradual replacement of one plant community by another over a period of time, through a series of seral stages ending with a climax community. the gradual replacement of one plant community by another over a period of time, through a series of seral stages ending with a climax community. Deflected succession Deflected succession the original path of succession is deflected by human activity (e.g. deforestation, burning) to form a plagioclimax. the original path of succession is deflected by human activity (e.g. deforestation, burning) to form a plagioclimax. A plagioclimax can be maintained by mowing, grazing or burning A plagioclimax can be maintained by mowing, grazing or burning

4 Grassland Management Grazing species – sheep, goats, cattle, horses and llamas Grazing species – sheep, goats, cattle, horses and llamas Each species has a preferred grazing behaviour. Each species has a preferred grazing behaviour. Nutrient poor grassland is often rich in plant species, high densities of cattle can produce nutrient rich but species- poor grassland. Nutrient poor grassland is often rich in plant species, high densities of cattle can produce nutrient rich but species- poor grassland.

5 Effects of overstocking The growth rate of the grass can not support the amount of animals grazing on the land The growth rate of the grass can not support the amount of animals grazing on the land Damaged vegetation Damaged vegetation Bare earth Bare earth Increase in soil erosion by wind and rain Increase in soil erosion by wind and rain Examples Examples Australia Australia St Helena in South Atlantic St Helena in South Atlantic

6 Moorland Management Heather moorland is a plagioclimax maintained by humans for game management, and also by grazing Heather moorland is a plagioclimax maintained by humans for game management, and also by grazing Uncontrolled peat fires are disastrous and the desert-like aftermath if likely to persist for decades. Uncontrolled peat fires are disastrous and the desert-like aftermath if likely to persist for decades.

7 Effects of muirburn on the land If the heather is burned infrequently If the heather is burned infrequently The heather becomes too old and woody, and regrowth from the stem base is poor. The heather becomes too old and woody, and regrowth from the stem base is poor. Poor regeneration, undesirable species spread e.g. bracken Poor regeneration, undesirable species spread e.g. bracken If heather is burned too frequently If heather is burned too frequently Decline in the carrying capacity of wildlife, grazing and game species. Decline in the carrying capacity of wildlife, grazing and game species. Deplete soil of minerals and nutrient essential for plant and animal growth. Deplete soil of minerals and nutrient essential for plant and animal growth. Spread of undesirables at the expense of the heather Spread of undesirables at the expense of the heather

8 Grassland – a plagioclimax maintained by grazing

9 Moorland – a plagioclimax maintained by muirburn

10 Pupil Activity Read the handout – upland land management Read the handout – upland land management Highlight the main points Highlight the main points

11 Pupil Activity Suggest what effects the following might have on the numbers of grouse, and why:- Suggest what effects the following might have on the numbers of grouse, and why:- More frequent burning of moors More frequent burning of moors Less frequent burning of moors Less frequent burning of moors This will be marked out of ten. This will be marked out of ten.

12 Food Production 2 main types of agricultural ecosystem 2 main types of agricultural ecosystem Industrialised Industrialised uses large amounts of fossil fuel energy, water, fertilisers and pesticides to increase net production. uses large amounts of fossil fuel energy, water, fertilisers and pesticides to increase net production. Traditional Traditional low input agricultural practices. low input agricultural practices. 1 st green revolution (1950s) 1 st green revolution (1950s) An increase in food production resulted from increased yields per unit of farmed land. An increase in food production resulted from increased yields per unit of farmed land. 2 nd green revolution (last 30 years) 2 nd green revolution (last 30 years) Use of fast growing, high yielding varieties of rice, corn and wheat. Use of fast growing, high yielding varieties of rice, corn and wheat. More food from less land, increase in per capita food production. More food from less land, increase in per capita food production.

13 Two green revolutions Study the map showing countries whose crop yields per unit area of land increased during the two green revolutions. Study the map showing countries whose crop yields per unit area of land increased during the two green revolutions. Summarise where the two industrial revolutions mainly took place. Summarise where the two industrial revolutions mainly took place.

14 Locations of major types of food production Study the map, summarise the locations of the world’s principal types of food production. Study the map, summarise the locations of the world’s principal types of food production. Make notes on each type of food production Make notes on each type of food production

15 Questions on food production use the handout to help answer these three questions Suggest a reason for the decline in per capita production of grain in the last decade Suggest a reason for the decline in per capita production of grain in the last decade Suggest two reasons why wheat is the world’s most important cereal crop. Suggest two reasons why wheat is the world’s most important cereal crop. Suggest why rice is less important as an export crop than wheat or maize. Suggest why rice is less important as an export crop than wheat or maize.

16 Total world grain production

17 World grain production per capita

18 Extensive farming Production of crops and livestock raised on land, which has little, or no fertiliser added. Production of crops and livestock raised on land, which has little, or no fertiliser added. Annual yields very low. Annual yields very low. Examples – upland sheep, grain production in semi-arid areas, conifer forestry, some meat and dairy farms. Examples – upland sheep, grain production in semi-arid areas, conifer forestry, some meat and dairy farms. Upland areas in U.K. now in danger of overstocking. Upland areas in U.K. now in danger of overstocking.

19 Intensive farming This is an open system; there is a net loss of nutrients as large yields are being exported from the farms, which then has to be replaced by fertilisers. This is an open system; there is a net loss of nutrients as large yields are being exported from the farms, which then has to be replaced by fertilisers. Animals are farmed at high densities, which increase the chance of catching diseases due to stress, and overcrowding, this leads to antibiotics being added to their food. Animals are farmed at high densities, which increase the chance of catching diseases due to stress, and overcrowding, this leads to antibiotics being added to their food.

20 Comparison intensive and extensive farming Yields are given in nitrogen per hectare Extensive farms Extensive farms 1-20Kg/hectare 1-20Kg/hectare Intensive farms Intensive farms 15 – 40kg/hectare for lowland animals 15 – 40kg/hectare for lowland animals > 150Kg for vegetable crops > 150Kg for vegetable crops

21 Pupil Activity With the use of a highlighter, read the handout on intensive farming – advantages and disadvantages. With the use of a highlighter, read the handout on intensive farming – advantages and disadvantages.

22 GMO Technology Read the article “Science Friction”, taken from the BBC Wildlife magazine. Read the article “Science Friction”, taken from the BBC Wildlife magazine. Answer the questions provided. Answer the questions provided. With the use of a highlighter – read through the additional photocopies on GMO technology. With the use of a highlighter – read through the additional photocopies on GMO technology.

23 General environmental effects of food production

24

25

26 “The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and ecosystems” “The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and ecosystems” Convention on Biological Diversity, Rio 5 th June 1992 Convention on Biological Diversity, Rio 5 th June 1992

27 General environmental effects of food production

28 Major changes in agricultural activity in the U.K. since the 1940’s Increasing levels of farm mechanisation, energy inputs and decline in the labour force Increasing levels of farm mechanisation, energy inputs and decline in the labour force Development of highly productive strains of crops and livestock Development of highly productive strains of crops and livestock Increasing use of fertilisers and pesticides. Increasing use of fertilisers and pesticides. Changes in farm sizes. Changes in farm sizes. Changes in farming practices and significance of different crops. Changes in farming practices and significance of different crops. Financial returns. Financial returns.

29 Pupil Activity Diagram – consequences of modernisation of agriculture on ecology and wildlife interests of farmland. Diagram – consequences of modernisation of agriculture on ecology and wildlife interests of farmland. Stick the diagram into your book Stick the diagram into your book Write out a paragraph discussing the diagram, including any comments that you can draw form the diagram. Write out a paragraph discussing the diagram, including any comments that you can draw form the diagram.

30 Pollution from farm wastes Arable Farming Arable Farming Nitrogen from fertilisers can build up in the soil. Soil bacteria then convert this to nitrates. The nitrates then get into stream and river systems through surface run off. Nitrogen from fertilisers can build up in the soil. Soil bacteria then convert this to nitrates. The nitrates then get into stream and river systems through surface run off. Livestock Farming Livestock Farming Stackable manure Stackable manure Slurry Slurry kept in large tanks or lagoons kept in large tanks or lagoons can be spread on fields as fertilisers, but often has the wrong N:P:K ratio. can be spread on fields as fertilisers, but often has the wrong N:P:K ratio. If animals are kept enclosed, then the problem of manure disposal increases. If animals are kept enclosed, then the problem of manure disposal increases.

31 Pollution from Farm Wastes Specialisation of farming Specialisation of farming Livestock farms, which have excess slurry, are often nowhere near arable farms. Livestock farms, which have excess slurry, are often nowhere near arable farms. This leads to accidental or deliberate leakage of slurry, which finds its way into watercourses. This contributes to eutrophication. This leads to accidental or deliberate leakage of slurry, which finds its way into watercourses. This contributes to eutrophication. Other problems from farm waste include growth hormones and antibiotics which the animals are fed with. Other problems from farm waste include growth hormones and antibiotics which the animals are fed with.

32 Land reclamation for agriculture Fertile land is highly valued, and there is a strong drive to get more land under intensive farming. Fertile land is highly valued, and there is a strong drive to get more land under intensive farming. This can lead to problems when the land is either a National Park or low-lying wetlands. This can lead to problems when the land is either a National Park or low-lying wetlands. Land reclamation for agriculture destroys important marine defences and freshwater marsh habitats. Land reclamation for agriculture destroys important marine defences and freshwater marsh habitats. Land reclaimed from the sea, needs constant maintenance of sea defences, which is expensive. Land reclaimed from the sea, needs constant maintenance of sea defences, which is expensive.

33 Hedgerow Destruction Hedgerow Hedgerow narrow belt of vegetation dominated by shrubs and occasional trees. narrow belt of vegetation dominated by shrubs and occasional trees. Traditionally hedgerows served two functions Traditionally hedgerows served two functions A barrier to the movement of livestock. A barrier to the movement of livestock. Marking property boundaries. Marking property boundaries.

34 Hedgerows have a high landscape and conservation value They are a traditional feature of the landscape and add diversity to it. They are a traditional feature of the landscape and add diversity to it. Provide foraging, roosting and nesting sites for birds. Provide foraging, roosting and nesting sites for birds. Rich in plant and animal species. Rich in plant and animal species. Act as a source of beneficial insects. Act as a source of beneficial insects. Act as wildlife corridors through an increasingly hostile agricultural landscape. Act as wildlife corridors through an increasingly hostile agricultural landscape.

35 Hedgerow losses Hedgerow losses Estimated that between 1945 and 1970 there was an annual loss of about 8,000km year -1 in the U.K. Estimated that between 1945 and 1970 there was an annual loss of about 8,000km year -1 in the U.K. In the 1990’s it is estimated that the U.K. was still losing 5,000 – 6,000 Km year -1. In the 1990’s it is estimated that the U.K. was still losing 5,000 – 6,000 Km year -1.

36 Advantages of Hedgerow removal to the farmer Hedgerows act as a refuge for weeds, diseases and crop pests. Hedgerows act as a refuge for weeds, diseases and crop pests. Reduce the loss of crop yields adjacent to the hedge Reduce the loss of crop yields adjacent to the hedge Bigger field sizes – decreases the amount of land needed for turning machinery. Bigger field sizes – decreases the amount of land needed for turning machinery.

37 Disadvantages of Hedgerow removal to the farmer Increases soil erosion Increases soil erosion Reduce crop yields through the loss of beneficial insect species Reduce crop yields through the loss of beneficial insect species Predators for pest control Predators for pest control Pollinators Pollinators

38 Pupil Activity On one side of A4 paper On one side of A4 paper Compare and contrast intensive and extensive farming (15 marks) Compare and contrast intensive and extensive farming (15 marks) Using a highlighter – read through the three articles on farming from the BBC Wildlife magazine. Using a highlighter – read through the three articles on farming from the BBC Wildlife magazine.

39 History of Organic Farming Organic farming can be split into two categories: Organic farming can be split into two categories: Natural form of farming. E.g. traditional small scale or subsistence farmers. Natural form of farming. E.g. traditional small scale or subsistence farmers. A recent development seeing a move from intensive farming to organic farming where the aim is to produce food crops by building up soil fertility using the minimum of non-renewable resources and minimum damage to environment. A recent development seeing a move from intensive farming to organic farming where the aim is to produce food crops by building up soil fertility using the minimum of non-renewable resources and minimum damage to environment. UK Register of organic food standards UK Register of organic food standards This is a monitoring association, which checks farmers fulfil criteria governed by EU regulations. This is a monitoring association, which checks farmers fulfil criteria governed by EU regulations.

40 Reading Handout – the advantages and disadvantages of organic farming Handout – the advantages and disadvantages of organic farming Pages of environmental biology – looks at the advantages and disadvantages to the environment and to the consumer. Pages of environmental biology – looks at the advantages and disadvantages to the environment and to the consumer.

41 Traditional Farming Methods Crop rotation Intercropping

42 Crop Rotation A different crop is grown in the field each year. Once every few years a crop of legumes is used to increase the nitrogen content of the soil. A different crop is grown in the field each year. Once every few years a crop of legumes is used to increase the nitrogen content of the soil. Nitrogen fixation is the reduction of atmospheric N 2 to the ammonium ion, NH­ 4 +. Nitrogen fixation is the reduction of atmospheric N 2 to the ammonium ion, NH­ 4 +. Rhizobium are nitrogen-fixing bacteria. Rhizobium live in root nodules of legumes e.g. peas, beans, clovers and peanuts Rhizobium are nitrogen-fixing bacteria. Rhizobium live in root nodules of legumes e.g. peas, beans, clovers and peanuts

43 Crop Rotation The enzyme responsible for nitrogen fixation is nitrogenase, farmers are looking at breeding (through genetic engineering) the ability of N 2 fixation in crops e.g. rice and wheat The enzyme responsible for nitrogen fixation is nitrogenase, farmers are looking at breeding (through genetic engineering) the ability of N 2 fixation in crops e.g. rice and wheat Crop rotation is used as a form of biological pest control, as it reduces the survival of weeds, pests and diseases specific to particular crops. Crop rotation is used as a form of biological pest control, as it reduces the survival of weeds, pests and diseases specific to particular crops.

44 Intercropping Small farms increase yields by growing more than one crop in the same field at the same time. Small farms increase yields by growing more than one crop in the same field at the same time. Crops can be grown in rows or all mixed together. Crops can be grown in rows or all mixed together. Common in tropical areas where the growing season lasts all year round. Common in tropical areas where the growing season lasts all year round. The main principle of intercropping is to increase overall yield of land available by growing different and complementary plants together. The main principle of intercropping is to increase overall yield of land available by growing different and complementary plants together. E.g. short and tall, annuals and perennials, legumes and high nitrogen requirers E.g. short and tall, annuals and perennials, legumes and high nitrogen requirers

45 Advantages of Intercropping Decrease in soil erosion, due to harvesting of crops at different times. Decrease in soil erosion, due to harvesting of crops at different times. biological pest control, this can reduce pest damage by up to 80%, as predators for pests of one crop hide in another. biological pest control, this can reduce pest damage by up to 80%, as predators for pests of one crop hide in another.

46 Pupil Activity Discuss the use of intercropping and crop rotation with legumes as a method of cultivating crops in developing countries. Discuss the use of intercropping and crop rotation with legumes as a method of cultivating crops in developing countries.

47 Biological Pest Control Use of natural predators, parasites or disease organisms to control pests on field crops and in glasshouses Pests that can be controlled include insects, fungi, nematodes and weeds. Pests that can be controlled include insects, fungi, nematodes and weeds.

48 Two types of Biological Pest Control Open farmland – basic biological control, where natural wildlife predators are encouraged. Open farmland – basic biological control, where natural wildlife predators are encouraged. hoverfly larvae and ladybirds eat greenfly. hoverfly larvae and ladybirds eat greenfly. Enclosed cultivation in greenhouses and glass house systems. One predator is actively released into an enclosed area. Enclosed cultivation in greenhouses and glass house systems. One predator is actively released into an enclosed area. parasitic wasp, Encarsia, controls white fly infestation of plants. parasitic wasp, Encarsia, controls white fly infestation of plants.

49 Advantages of Biological Pest Control Avoids the use of chemical sprays Avoids the use of chemical sprays Pesticides may be so damaging to natural predators what it allows pest species to increase. Pesticides may be so damaging to natural predators what it allows pest species to increase. e.g. cabbage white butterfly e.g. cabbage white butterfly

50 Disadvantages of Biological Pest Control Time lag to allow natural predator populations to build up Time lag to allow natural predator populations to build up Predator population may be affected by pesticide use in neighbouring areas Predator population may be affected by pesticide use in neighbouring areas In enclosed sites, control species may have to be bought and released. In enclosed sites, control species may have to be bought and released. Introduce predator which may escape or lead to its own problems Introduce predator which may escape or lead to its own problems e.g. Polynesia and the introduction of the giant African land snail (pg 23 – Env. Biology) e.g. Polynesia and the introduction of the giant African land snail (pg 23 – Env. Biology)

51 Biological Control Snail genus Partula in Polynesia, African Land Snail Achatina introduced in 1960s as human food source – escaped from captivity and ate native vegetation and crops, introduced small predator snail Euglandina to kill giant snails. Snail genus Partula in Polynesia, African Land Snail Achatina introduced in 1960s as human food source – escaped from captivity and ate native vegetation and crops, introduced small predator snail Euglandina to kill giant snails. But it ate natives instead – wiped out 40 species, now only Partula left live in captivity as Achatina keeps on munching! But it ate natives instead – wiped out 40 species, now only Partula left live in captivity as Achatina keeps on munching!

52 Pupil Activity Question 3 – Specimen Exam Paper Question 3 – Specimen Exam Paper Peach potato aphid Peach potato aphid

53 Integrated Pest Management In IPM, each crop and its pests are evaluated as part of an ecological system. A control programme is developed that includes a sequence of crop management, and biological and chemical controls. In IPM, each crop and its pests are evaluated as part of an ecological system. A control programme is developed that includes a sequence of crop management, and biological and chemical controls. The aim of IPM is not pest eradication but a reduction in crop damage to an economically tolerable level. Well managed IPM systems are recognised as being economically and ecologically sound. The aim of IPM is not pest eradication but a reduction in crop damage to an economically tolerable level. Well managed IPM systems are recognised as being economically and ecologically sound.

54 Crop Monitoring 1. Cultivation controls 2. Biological controls 3. Targeted pesticide use

55 Revision Activity The land Debate The land Debate Handout – scene setting, character cards. Handout – scene setting, character cards.


Download ppt "Agriculture and the Environment OCR A2 Options Environmental Biology."

Similar presentations


Ads by Google