Earth Systems

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Earth Systems Resources

• Chapter 14
• Food Soil Resources

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14.1 Types of Agriculture
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Wheres the food from?

• Cropland produce mostly grains. 77 of worlds
  food
• Rangeland produce meat (grazing livestock). 16
  of worlds food
• Ocean fisheries seafood products. 7 of worlds
  food

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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 worlds people survive mostly on these
  grains and little to no meat.

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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

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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.

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Traditional Agriculture

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

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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

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Centers of ancient intensive agriculture based
civilizations
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14.2 Green Revolution

• (view time 505)
• Answer questions on sheet

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14.3 Soil Erosion Degradation
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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.

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Soil Erosion

• Causes damages to
• 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

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Learn from the past Dust Bowl

• Dust bowl occurred in 1930s (dirty thirties)
• Kansas,
• Oklahoma
• and Texas

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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

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Learn from the past Dust Bowl(View time 103)
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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.

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Desertification

• Desertification productive land that has lost
  its 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.

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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

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Bad News for Dirt

• UN survey topsoil is eroding faster than it can
  be replaced in about 38 of worlds 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 10-15 years.

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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.

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

• A problem with irrigation
• Water gets trapped under the surface, but cant
  percolate downward less permeable layers of
  soil underneath
• Plant roots are then saturated with saline water

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14.4 Soil Conservation

• Dont take notes for this section!

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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.

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Terracing change hillsides into steps. Slows
water running off.
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Contour farming planting crops across the hill
slope instead of up and down. Also slows water
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Strip cropping Planting alternating rows of
cover crop with row crops. The cover crop traps
the soil that erodes from row crop.
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Windbreaks AKA shelterbelts. Reduces wind
speed, roots hold soil, reduce evaporation
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Alley cropping AKA agroforestry. Planting
crops in alleys between rows of trees or shrubs.
Holds soil and reduces evaporation
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Cover crops planting cover crops (alfalfa,
clover, etc) immediately after harvest to hold
soil in place over winter.
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14.5 Nutrition
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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.

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Malnutrition

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

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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)

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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

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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.

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14.6 Increasing Crop Production
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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!!

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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)

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14.7 Producing More Meat
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Wheres 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.

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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.

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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.

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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
  (708)
• Traditional intensive agriculture 1 unit energy
  input to up to 10 units food output.

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Increase in Meat Production

• Between 1950-2000, world meat production has
  increased five times.
• Per capita meat production has more than doubled.
• Remember affluenza!

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14.8 Fishing Worksheet to come
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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.

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14.10 Sustainable Agriculture

• What Can You Do?

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Solutions
Sustainable Agriculture
Increase
Decrease
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
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 Subsidi
es for more sustainable farming and fishing
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Buy organic food
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Feed pets balanced grain foods instead of meat
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• Compost your food wastes

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Please dont waste food
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