1. GEOG 101
Fall 2013
Jeff Lewis
Agriculture

2. Learning Outcomes: At the end of this lecture, you should be able to:
State the importance of soils for agriculture and in supporting plant growth
Outline the historical development of agriculture and the transition to industrialized agriculture
Identify the causes of soil erosion and soil degradation, and explain the basic principles of soil conservation
Explain the challenge of feeding a growing human population
Evaluate sustainable agriculture
Describe the science behind genetically modified food
and evaluate controversies over genetically modified food

3. Why Should You Care About Food Resources
Three major reasons
Food required for healthy & productive life
1 billion people do not get enough food
Food production large environmental impact
- 38% of world’s ice free land in agriculture
- 70% of freshwater used for agriculture
- 60% of water pollution
- 25% of human greenhouse gases

4. Most of Canada's wasted food dumped from homes
$27B worth of food wasted across the country every year, research group says

5. 7 ways to reduce household food waste
1. Take stock before you shop
2. Plan your meals
3. Be smart about expiration dates
4. Don't assume you need to buy in bulk
5. Learn the art of pre-portioning
6. Use more of your fruits and veggies
7. Think twice before tossing overripe fruits and veggies

6. Soil a complex plant-supporting system consisting of:
disintegrated rock
organic matter
water
gases
nutrients
microorganisms
Soil cannot be considered a renewable resource as it takes 500 to 1000 years to produce 2.5 cm of topsoil

8. Percent of land use for growing crops

9. Food Choices
There are fewer than two dozen species of major food sources. They all share three characteristics:
1. High yield
High production per unit area of land. Essential to subsistence farmers dependant on small parcels of land
2. High food value
Staple foods have high total calories and essential nutrients: carbohydrates, proteins, fats and vitamins
Most subsistence farmers plant a grain or tuber crop for caloric intake and then vegetables and fruit for additional nutrients
3. Storage ability
Most foods are harvested at a certain time of year and must last until the next harvest

10. Food Choices Top five global crops: Potato Cassava (Manioc) Wheat Rice
Corn (Maize)

11. Food Choices Efficiency 90% of human food comes from plants
Developing World
are more efficient than developed world because they rely on the lowest trophic level in the energy pyramid

12. Food Choices Efficiency 90% of human food comes from plants
Developed World
most agriculture aimed at livestock and the crops that feed them
vast amounts of food energy is used in producing animal protein

13. Consumption of animal products is growing
FIGURE 8.15

14. Our food choices are also energy choices
90% of energy is lost every time energy moves from one trophic level to the next
The lower on the food chain from which we take our food sources, the more people the Earth can support
FIGURE 8.17

15. Environmental ramifications of eating meat
Land and water are needed to raise food for livestock
Producing eggs and chicken meat requires the least space and water; beef requires the most
FIGURE 8.18
When we choose what to eat, we also choose how we use resources

16. The Evolution of Agriculture
Agriculture led to:
stable food source
urban centres
specialization
-stable food source led to development of town and specialization -

17. Systems of Agricultural Production
Subsistence Agriculture: basic needs are met with a small surplus for trade or store
most widespread agricultural system in the world
Three Subsistence Agricultural Methods:
Intensive Subsistence Farming: supports dense populations as it produces relatively high yields per unit of land
Shifting cultivation: supports small populations, requires large areas
Nomadic herding: supports very small populations, based on seasonal migration

18. Systems of Agricultural Production
Industrial Revolution
Mechanization enabled farmers to specialize and mass produce
led to commercial agricultural systems that dominated regions

19. Systems of Agricultural Production
Wheat
Dairy
General
Range
Cotton

20. Systems of Agricultural Production
Industrial Agriculture: emphasize specialized production of crops and livestock to sell
can produce enough food to feed many other people
Production efficiency is achieved in two ways:
improved inputs such as seeds, irrigation, fertilizers and pesticides promote higher yield
Specialized machinery speeds up production and requires fewer people, uses fossil fuels

21. Fertilizers boost yields but can be overapplied
Fertilizer = substances that contain essential nutrients
Inorganic fertilizers = mined or synthetically manufactured mineral supplements
Organic fertilizers = the remains or wastes of organisms
manure, crop residues, fresh vegetation
Compost = produced when decomposers break down organic matter

22. Fertilizers boost yields but can be overapplied

23. Soil degradation: We lose 5-7 million hectares of productive cropland annually
FIGURE 7.6

24. Soil degradation has many causes
Soil degradation results from deforestation, agriculture and overgrazing
Over the past 50 years, soil degradation has reduced global grain production by 13%
FIGURE 7.7

25. Agriculture and the Environment
Increased demand for food has led to an expansion of cropland and techniques that produce higher yields
This has led to worldwide environmental degradation
The main causes of degradation are:
Soil Erosion
Desertification
Overgrazing
Salinization and Waterlogging
Groundwater Depletion and Contamination
Surface Water Impacts
Simplification and Substitution

26. Agriculture and the Environment
Key is increased soil conservation
Systems to reduce soil erosion:
Intercropping
Terracing
Contour planting and strip cropping
Crop rotation
Reduce tillage
Remove land from agriculture

27. We are producing more food per person
FIGURE 8.1
Food security = the guarantee of an adequate, reliable, and available food supply to all people at all times

28. We face both too little and too much food
Undernourishment = people receive less than 90% of their daily caloric needs
Mainly in developing countries
Malnutrition = a shortage of nutrients the body needs
The diet lacks adequate vitamins and minerals
Overnutrition = receiving too many calories each day
In Canada, 48% of adults exceed their healthy weight and ~25% are obese
Between 1981 and 2009, measured obesity doubled
Obesity in Canada: A joint report from the Public Health Agency of Canada and the Canadian Institute for Health Information (2011)
Obesity in Canada is a joint report from the Canadian Population Health Initiative of the Canadian Institute for Health Information and the Public Health Agency of Canada. The joint report examines the prevalence of obesity among adults, children, youth and Aboriginal Peoples; presents new analyses of the determinants of obesity using innovative measures; and reports on the impact of obesity in Canada. In addition, Canadian and international lessons learned in obesity prevention and reduction are highlighted.

29. New Horizons in World Agriculture
The Green Revolution: the use of new technology, crop varieties and farming practices introduced to developing countries
the Green Revolution led to a tripling of grain yields between 1950 and 1990
From 1900 to 2000, humans expanded the world’s total cultivated area by 33% and energy inputs increased by 80 times:
Synthetic fertilizers
Chemical pesticides
Irrigation
Heavy equipment

30. New Horizons in World Agriculture
Shortcomings of the Green Revolution
limited participation by small, subsistence farmers
increased mechanization and farm size
increased commercialization
loss of genetic diversity (monocultures)
reduction in soil fertility and increased erosion potential
soil damage and water resource depletion from increased irrigation
many regions initially bypassed by the Green Revolution

31. Pests and pollinators Pest = any organism that damages valuable crops
Weed = any plant that competes with crops
FIGURE 8.4
Armyworms easily defoliate monocultures

32. Many thousands of chemical pesticides have been developed
Pesticides = poisons that target pest organisms
Insecticides = target insects
Herbicides = target plants
Fungicides = target fungi
91% of pesticide sales are for agricultural purposes
85% of pesticides sold in Canada are herbidices

33. Pests evolve resistance to pesticides
Resistance is passed through their genes to insect offspring
Pesticides stop being effective
Evolutionary arms race: chemists increase chemical toxicity to compete with resistant pests

34. Biological control pits one organism against another
Biological control (Biocontrol) = uses a pest’s natural predators to control the pest
Problem. Mongoose in Hawaii to kill rats. Have killed ground nesting birds.
FIGURE 8.6

35. Biocontrol agents themselves may become pests
No one can predict the effects of an introduced species
The agent may have “nontarget” effects on the environment and surrounding economies
Removing a biocontrol agent is harder than halting pesticide use
Due to potential problems, proposed biocontrol use must be carefully planned and regulated

36. Integrated Pest Management (IPM) combines biocontrol and chemical methods
IPM uses multiple techniques to suppress pests
Biocontrol
Chemicals, when necessary
Population monitoring
Habitat alteration
Crop rotation and transgenic crops
Alternative tillage methods
Mechanical pest removal

37. We depend on insects to pollinate crops
Pollination = male plant sex cells fertilize female sex cells
Value of insect pollination services in Canada is $1.2 billion
Animals pollinate 75% of the world’s staple crops and 90% of all non-food flowering plants.
FIGURE 8.8
Flowers are evolutionary adaptations to attract pollinators

38. Conservation of pollinators is vital
Beekeepers are hired regularly to bring honeybee colonies to crops for pollination
To conserve bees:
Reduce or eliminate pesticide use
hopes-of-upturn
regulation

39. Crossbreeding and Genetic Engineering
Early efforts at crop improvement - Crossbreeding, or artificial selection - Many current crops produced this way - Requires long periods of time Genetic engineering - Adding, removing or changing DNA directly - produces genetically modified organisms (GMOs) - Similar to crossbreeding, but can use new genes - Much faster than crossbreeding - Can yield improvements quickly, but controversial

40. Genetic engineering is like, and unlike, traditional agricultural breeding
Scientific techniques to develop more productive crops and livestock has been around for more than a century
Similar:
Both alter gene pools for preferred characteristics
Both apply to plants and animals
Different:
Traditional breeding uses genes from the same species
Selective breeding deals with whole organisms, not just genes
In traditional breeding, genes come together on their own

41. weighing the issues
GM foods and you
Do you think you have ever eaten a food product that contained genetically modified organisms?
As much as 70% of the food products on shelves in North American grocery stores contain at least some GM ingredients.
Check your kitchen cupboards for any foods that contain products or ingredients made from corn, soy, or canola.

42. Biotechnology is transforming the products around us
FIGURE 8.12
2006: Globally, GM foods grew on 106 million hectares of farmland, producing $6.15 billion worth of crops

43. Biotechnology Concerns of transgenic crops
herbicide resistant crops will encourage the use of herbicides (kills non-target species and pollutes soil/water)
crops might transfer their herbicide tolerance to closely related weeds (super weeds)
built-in pesticides will promote rapid evolution of resistant pests (super pests)
may permanently alter wild plants and reduce diversity
genetically engineered seeds add to production costs
only a small group of N.A. and European companies will control most of the worlds certified seed supply
health concerns have led to a debate about labelling

44. Precautionary principle
Supporters make the following points:
GM crops pose no ill health effects
They benefit the environment by using less herbicides
Herbicide-resistant crops encourage no-till farming
GM crops reduce carbon emissions by needing fewer fuel-burning tractors and sequestering carbon in the soil by no-till farming
Critics argue that we should adopt the precautionary principle = don’t do any new action until it is understood
CBC
Guardian

45. Debate over GM foods involves more than science
Ethical issues play a large role
People don’t like “tinkering” with “natural” foods
With increasing use, people are forced to use GM products, or go to special effort to avoid them
Multinational corporations threaten the small farmer
Research is funded by corporations that will profit if GM foods are approved for use
Crops that benefit small, poor farmers are not widely commercialized

46. Sustainable Agriculture
Sustainable agriculture = does not deplete soil, pollute water, or decrease genetic diversity
Low-input agriculture = uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuel energy than industrial agriculture
Organic agriculture = Uses no synthetic fertilizers, insecticides, fungicides, or herbicides
Relies on biological approaches (composting and biocontrol)
2009: Organic Products Regulations
Multi-ingredient products must be 95% organic
Organic certification logo
On June 30, 2009, the Organic Products Regulations (OPR) came into effect, making the Canadian Organic Standards (COS) mandatory. The OPR will legally require organic products to be certified according to the COS if they are traded across provincial or international borders or use the Canada Organic Logo

47. The benefits of organic farming
For farmers:
Lower input costs, enhanced income from higher-value products, reduced chemical costs and pollution
Obstacles include the risks and costs of switching to new farming methods and less market infrastructure
For consumers:
Concern about pesticide’s health risks
A desire to improve environmental quality
Obstacles include the added expense and less aesthetically appealing appearance of the product

48. Locally supported agriculture is growing
The average food product sold in North America travels at least 2300 km between the farm and the shelf, and is often chemically treated to preserve freshness and colour.
Farmers and consumers are supporting local agriculture
Fresh, local produce in season
Community-supported agriculture = consumers pay farmers in advance for a share of their yield
Consumers get fresh food
Farmers get a guaranteed income
Community gardens = areas where residents can grow their own food
Makaria Farm
Alderlea Farm

49. Summary
Intensive commercial agriculture has substantial negative environmental impacts
If our planet will be able to support 9 billion humans, we must shift to sustainable agriculture
Biological pest control
Organic agriculture
Pollinator protection
Preservation of native crop diversity
Careful, responsible genetic modification of food
Feeding Nine Billion: A Solution to the Global Food Crisis by Dr. Evan Fraser