1. Earth Systems & Resources
Chapter 14
Food & Soil Resources

2. 14.1 Types of Agriculture

3. Where’s the food from?
Cropland: produce mostly grains. 77% of world’s food
Rangeland: produce meat (grazing livestock). 16% of world’s food
Ocean fisheries: seafood products. 7% of world’s food

4. What feeds the world?
3 grain crops provide more than half the calories people consume.
Corn
Rice
Wheat
Annual crops (need replanted each year)
2/3 of the world’s people survive mostly on these grains and little to no meat.

5. Industrialized Agriculture
AKA: high-input agriculture
Uses large amounts of fossil fuel energy, water, commercial fertilizers, pesticides
Produces monocultures (single crop) or livestock for sale to others
Mostly in developed countries
Think John Deere

6. Plantation Agriculture
A form of industrialized agriculture
Involves large monocultures of cash crops such as:
Bananas
Coffee
Soybeans
Sugarcane
Cocoa
Vegetables
Mostly in tropical areas of developing countries
Products usually exported to developed countries.

7. Traditional Agriculture
Traditional subsistence agriculture: utilizes human labor, draft animals in order to produce enough food for family to eat
Think: old work horse

8. Traditional Agriculture
Traditional intensive agriculture: still human labor and animals, but also uses fertilizer, primitive irrigation to get higher yields. Enough to feed family and surplus to sell.
Think: China

9. Centers of ancient intensive agriculture based civilizations

10. Industrialized agriculture
Shifting cultivation
Plantation agriculture
Nomadic herding
Intensive traditional agriculture
No agriculture

11. (view time 5:05) Answer questions on sheet
14.2 Green Revolution
(view time 5:05)
Answer questions on sheet

12. 14.3 Soil Erosion & Degradation

13. Soil Erosion Three main causes of soil erosion:
Water
Wind
People
Land degradation: natural or human activity that decreases soils ability to support plants or living organisms.
Soil erosion: movement of soil from one place to another. Typically from wind or water.
Human activities that increase soil erosion: burning ditches, ATV use, logging, farming, overgrazing of livestock, monoculture, constructuion, etc.

14. Soil Erosion Causes damages to Interferes with Common types
Agriculture
Waterways (canals)
Infrastructures (dams)
Interferes with
Wetland ecosystems
Reproductive cycles (as in salmon)
Oxygen capacity
pH of water.
Common types
Sheet – soil moves off in horizontal layer
Rill – fast H20 cuts small channels in soil
Gully – more extreme version of rill

15. Learn from the past – Dust Bowl
Dust bowl – occurred in 1930’s (“dirty thirties”)
Kansas,
Oklahoma
and Texas

16. Learn from the past – Dust Bowl
Effect: dust storms killed livestock and wild animals, families left the area in search of jobs, 1935 Soil Conservation Service was established

17. Learn from the past – Dust Bowl (View time 1:03)

18. Law to Know 1935 Soil Erosion Act
Established the Soil Conservation Service. Mandates the protection of the nations soil reserves. Deals with soil erosion problems, carries out soil survey, and does research on soil salinity.

19. Desertification
Desertification: productive land that has lost it’s productivity due to human activity and natural climate change.
Human causes: same as soil erosion – overgrazing, over tilling, destruction of natural grasses/plants, and surface mining.
You should be able to give many examples if asked how it is caused.
Consequences
Causes
Worsening drought
Famine
Economic losses
Lower living
standards
Environmental
refugees
Overgrazing
Deforestation
Erosion
Salinization
Soil compaction
Natural climate
change

20. Solutions to desertification
Low or no-till farming
Rotate grazing animals
Plant trees, native grasses
Reduce amount of land cleared of trees
Reduce harmful irrigation
Wait to plow farm fields until spring

21. Bad News for Dirt Good News for Dirt
UN survey: topsoil is eroding faster than it can be replaced in about 38% of world’s cropland.
Putting a price on it: $375 billion dollars a year spent on damages.
Good News for Dirt
In the US soil erosion has been cut by 2/3 since 1987.
US has government programs in place to continue to fight this problem. CRP land = government pays farmers to not farm land for years.

22. Salinization READ YOUR LAB HANDOUT!!!
Salinization: gradual build up of salts in soil. Caused by irrigation
How it happens:
groundwater naturally picks up various salts as it travels through rocks and mineral beds.
Plants are watered with this ground water through irrigation
These salts do not evaporate when the water does.
Salts build up in soil over time.

23. Figure 14-12 Page 283 Solutions Soil Salinization Prevention Cleanup
Reduce irrigation
Switch to salt-
tolerant crops
(such as barley,
cotton, sugar beet)
Flushing soil
(expensive and
wastes water)
Not growing crops
for 2-5 years
Installing under-
ground drainage
systems (expensive)

24. Waterlogging A problem with irrigation
Water gets trapped under the surface, but can’t percolate downward – less permeable layers of soil underneath
Plant roots are then saturated with saline water
Evaporation
Transpiration
Waterlogging
Less permeable
clay layer

25. Don’t take notes for this section!
14.4 Soil Conservation
Don’t take notes for this section!

26. Soil conservation
Conventional-tillage farming: frequently practiced in midwest. Plowing/disking of fields in fall so it is “ready” in the spring. Leaves topsoil vulnerable for months.
Conservation-tillage farming: little or no plowing prior to planting. Leave past crop residue on fields, do not plow in fall.
In 2004, 45% of farm fields utilized a form of conservation-tillage; USDA would like that number to grow to 80% of farm fields.

27. Terracing: change hillsides into “steps”. Slows water running off.

28. Contour farming: planting crops across the hill slope instead of up and down. Also slows water

29. Strip cropping: Planting alternating rows of cover crop with row crops
Strip cropping: Planting alternating rows of cover crop with row crops. The cover crop traps the soil that erodes from row crop.

30. Windbreaks: AKA – shelterbelts
Windbreaks: AKA – shelterbelts. Reduces wind speed, roots hold soil, reduce evaporation

31. Alley cropping: AKA – agroforestry
Alley cropping: AKA – agroforestry. Planting crops in alleys between rows of trees or shrubs. Holds soil and reduces evaporation

32. Cover crops: planting cover crops (alfalfa, clover, etc) immediately after harvest to hold soil in place over winter.

33. 14.5 Nutrition

34. Chronic Undernutrition
Marasmus: diet is low in both calories and protein. Typically breast feeding babies of malnourished mothers or those just weaned from nursing not getting enough to eat. Starvation.

35. Malnutrition
A general term for the medical condition caused by an improper diet or poor food quality.

36. Kwashiorkor
Kwashiorkor: severe protein deficiency. Can cause a bloated belly, discolored skin. Can happen when a 1-3 year old child is weaned from breast milk. They can get enough calories, but not enough protein. (not enough meat in diet or protein vegetables)

37. UNICEF and solutions Immunize children
Encourage breast feeding and maternal nutrition
Vitamin A capsule twice a year (75 cents)
Spacing births more than 2 years apart
Education for women on nutrition, child care, drinking water sterilization
Most deficient nutrients: vitamin A, iodine, and iron

38. Over-nutrition Over-nutrition leads to overweight and obese adults.
Health problems of over and under nutrition are very similar – lower life quality, lower life expectancy, susceptibility to disease.
About 1 in 7 adults in developed countries is overweight. US is one of the worst. Go figure!
Americans spend $40 billion a year on weight loss, but only $19 billion is spent worldwide on malnutrition.

39. 14.6 Increasing Crop Production

40. How can we feed the world?
Genetic engineering of crops –
Change our eating habits – try new foods, cultivate new crops, use the 1,500 species of edible insects.
YUM!!

41. How can we feed the world?
Polycultures of perennial crops
Reduce wasted food (70% of food is wasted through spoiling, poor processing, and plate waste)

42. 14.7 Producing More Meat

43. Where’s the beef?
It is more efficient to use land to produce grain for human consumption than to use it to produce meat for human consumption.
WHY??
When raising livestock you need land for the animals and land for the food for the animals.
It takes less energy to harvest grain than to process meat products.

44. Meat and potatoes for dinner?
Moderate grazing is actually good for vegetation.
Problem: most places use pastures where overgrazing occurs
Production of meat requires more energy and land than production of grains
Advantages to meat: high in protein, high in iron
Disadvantages to meat: high in fat, too much can lead to heart disease, high blood pressure, etc.

45. Home on the range? Grazing on ranges can be very hard on the area.
Grazing animals tend to overgraze and destroy riparian zones (located next to water)
Animal waste can end up in water supply
Grazing animals may only eat certain vegetation; other vegetation can then take over.

46. Developed countries
US consumers spend only about 2% of their income on domestically produced food. (farm products have dropped in cost, they now cost about 1/3 of what they did in 1910.)
10 units of energy (input) to produce 1 unit of food product (output) for industrialized agriculture.
Traditional subsistence agriculture: 1 unit energy input to 1 unit food output. Video clip (7:08)
Traditional intensive agriculture: 1 unit energy input to up to 10 units food output.

47. Increase in Meat Production
Between , world meat production has increased five times.
Per capita meat production has more than doubled.
Remember affluenza!

48. 14.8 Fishing
Worksheet to come

49. 14.9 Government Agricultural Policy
Government assistance:
Price controls to keep food prices low
Subsidies and tax breaks to farmers to encourage food production
If above two are eliminated, market demand would control costs.
Danger in this: lower income families might have harder time paying food costs. Would need more financial assistance for these people.

50. 14.10 Sustainable Agriculture
What Can You Do?

51. Sustainable Agriculture
Solutions
Sustainable Agriculture
Increase
Decrease
High-yield polyculture
Organic fertilizers
Biological pest control
Integrated pest
management
Irrigation efficiency
Perennial crops
Crop rotation
Use of more water-
efficient crops
Soil conservation
Subsidies for more sustainable farming and
fishing
Soil erosion
Soil salinization
Aquifer depletion
Overgrazing
Overfishing
Loss of
biodiversity
Loss of prime
cropland
Food waste
Subsidies for unsustainable
farming and fishing
Population growth
Poverty

52. Buy organic food

53. Feed pets balanced grain foods instead of meat

54. Compost your food wastes

55. Please don’t waste food