Food, Soil, and Pest Management

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Food, Soil, and Pest Management

• Chapter 10
• Morgan Green, James Lasky, Ryan McClain

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Food Production

• Can we produce enough food to meet the rising
  population and reduce poverty without degrading
  our croplands?

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Bug Cuisine

• Diet of wheat, rice, and corn does not provide
  enough protein? malnutrition Meat is too
  expensive, why dont we turn to bug farms?
• Winged Bean supermarket on a stalk, needs little
  fertilizer
• Microlivestock edible insects, protein and
  vitamins, i.e. Mopani (emperor moth caterpillars)
• Bug Farms
• Little or no need for fertilizer, pesticides,
  water
• Farmers- financial risk to cultivate new food
• Consumers- risk of trying new food

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Bugs as Food
Fig. 10-1, p. 206
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Industrialized vs. Traditional Food Production

• (Crop Lands 77 of worlds food, Rangelands 16,
  Oceanic fisheries 7)

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• a. Industrialized agriculture
• high-input
• large amounts of fossil fuel energy,water,
  commercial fertilizers, and pesticides
• b. Plantation agriculture
• Growing cash crops
• Primarily in tropical/developing countries

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• c. Traditional subsistence agriculture
• human labor/draft animals
• produces only enough for farm family to survive
  (practiced by 42 of the world)
• d. Traditional Intensive Agriculture
• increase input to obtain higher yield
• produce enough food to provide for family and to
  bring in an income

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Principal Types of Food Production
Industrialized agriculture
Plantation agriculture
Intensive traditional agriculture
Fig. 10-3, p. 208
Shifting cultivation
Nomadic herding
No agriculture
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Green Revolution

• First select key crops,
• Second produce high yields through high input
  fertilizer, pesticide, etc,
• Third increase crops grown per year through
  multiple cropping

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• 1950-1970 was first green revolution, second
  green revolution since 1967
• Yields depend on fertile soil, ample water, high
  inputs of fossil fuels to run machinery to
  produce/apply fertilizers
• agriculture uses 8 of worlds oil output cheap
  energy enable green revolution to occur 10 units
  of nonrenewable fossil fuel energy needed for 1
  unit of food energy to get to the table
• agribusiness big companies take over three
  fourths of U.S. food production, Increased
  efficiency increase erosion on forests,
  grasslands, wetlands converted to farmlands

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Green Revolutions
First green revolution (developed countries)
Second green revolution (developing countries)
Major international agricultural research centers
and seed banks
Fig. 10-5, p. 210
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Agricultural techniques and their effects
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Interplanting several crops grown on same plot

• Polyvarietal cultivation plot with several
  genetic varieties of the same crop
• Agroforestry/alleycropping crops and trees are
  grown together
• Polyculture many different plants maturing at
  various times
• less need for fertilizer, water because root
  systems at different depths
• more protection from wind/water erosion
• weeds have trouble competing

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Land Degradation

• natural or human induced processes decrease the
  ability of land to support crops

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Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 223
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Soil Erosion

• movement of soil (especially surface litter) from
  one place to another, caused by flowing water and
  wind
• Soil becomes more vulnerable to erosion after
  human activity
• Gully Erosion fast-flowing water joins together
  and cut wide channels through soil
• Loss of soil fertility and water pollution are
  outcomes of soil erosion
• Cultivated land eroding 16 times faster than it
  can farm
• Unites States is only country to sharply reduce
  soil loss by planting crops that do not disturb
  soil, since 1985 have cut losses by two-thirds

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Soil Erosion on Irrigated Cropland
Fig. 10-8, p. 212
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Desertificaition

• productive potential of dry lands falls by 10
  due to drought/human activities that
  reduce/degrade topsoil (only leads to a desert in
  extreme cases)
• Moderate 10-25 drop in productivity
• Severe 25-50
• Very severe 50 or more
• One third of worlds land and 70 of all dry land
  are suffering from effects of desertification

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World Desertification
Moderate
Severe
Very Severe
Fig. 10-11, p. 214
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Salination

• too much irrigation? gradual accumulation of
  salts in upper soil layers
• Stunts crop growth, lowers yields, eventually
  kills/ruins
• Has reduced crops in 1/5 of worlds irrigated
  cropland
• Most severe salination in Asia
• Remedies are too expensive

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Salinization and Waterlogging in Soils
Transpiration
Evaporation
Evaporation
Evaporation
Waterlogging
Less permeable clay layer
Fig. 10-13, p. 215
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Salinization from Heavy Irrigation
Fig. 10-14, p. 215
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Water logging

• large amounts of water to leech out salt? water
  accumulates underground and envelopes roots of
  plants, lowering productivity and killing them
• One tenth of irrigated land suffers from water
  logging

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Soil Conservation reduce soil erosion/ restore
soil fertility

• Conservation-tillage farming disturbs soil as
  little as possible while planting
• Minimum-tillage farming soild not disturbed over
  the winter
• No-till farming machines inject
  seeds/fertilizers/weed killers into slits
• Terracing converting land into series of broad,
  nearly level terraces? retains water and reduces
  erosion by controlling runoff
• Contour farming plowing/planting crops in rows
  across slope rather than up and down- small dams
  slow water runoff
• Strip cropping planting alternating strips of a
  row crop and another of ground cover
• Alley-cropping, agroforestry one or more crops
  are planted together in strips
• Windbreaks/shelter belts of trees to reduce wind
  erosion and help retain soil moisture, fire
  wood, habitats for pollinating birds

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Terracing
Fig. 10-16a, p. 217
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Contour Planting and Strip Cropping
Fig. 10-16b, p. 217
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Alley Cropping
Fig. 10-16c, p. 217
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Windbreaks
Fig. 10-16d, p. 217
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Fertilizer second best way to maintain soil
fertility

• Organic fertilizer made from plant/animals
  materials
• Animal manure
• green manure freshly cut vegetation
• compost produced when microorganisms in soil
  break down organic matter
• Crop rotation nutrient depleting crops one year,
  then legumes that add nutrient to the soil next
  year
• Inorganic commercial fertilizer typically
  contain nitrogen, phosphorus, and potassium
• one-fourth of worlds crop yields
• can replace depleted inorganic nutrients, but
  cannot replace organics matter

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Food production, nutrition, and environmental
effects
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Hunger and Malnutrition

• Macronutrients proteins, carbohydrates, fats
• Micronutrients vitamins and minerals
• Undernutrition
• when enough food to meet basic energy needs
  cannot be grown or bought
• Malnutrition
• deficiencies of protein, calories, and other key
  nutrients

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Overnutrition

• Overnutrition when food energy intake exceeds
  energy use and causes excess body fat
• Consequences
• Lower life expectancy
• Greater susceptibility to disease
• Lower productivity and life quality
• Obesity and overweight
• Leading cause of premature death
• Serious problem in the US
• Possible solutions

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Increasing Food Production

• Crossbreeding and Genetic Engineering

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Tradeoffs of Genetically Modified Foods
Trade-Offs
Genetically Modified Food and Crops
Projected Disadvantages
Projected Advantages
Need less fertilizer Need less water More
resistant to insects, plant disease, frost,
and drought Faster growth Can grow in slightly
salty soils Less spoilage Better flavor Less
use of conventional pesticides Tolerate higher
levels of pesticide use Higher yields
Irreversible and unpredictable genetic and
ecological effects Harmful toxins in food From
possible plant cell Mutations New allergens in
food Lower nutrition Increased evolution
of Pesticide-resistant Insects and plant
disease Creation of herbicide- Resistant
weeds Harm beneficial insects Lower genetic
diversity
Fig. 10-19, p. 221
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Increasing Meat Production through feedlots

• Animals are fattened with grain grown on cropland
  or meal produced from fish
• 43 beef, 50 pork, 75 poultry
• Results in overgrazing

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Overgrazing

• Occurs when too many animals graze and exceed the
  carrying capacity of a grassland.
• Results
• Soil erosion
• Desertification
• Lowered NPP of grassland vegetation

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Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 223
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Acquacultures

• the cultivation of aquatic populations under
  controlled conditions.

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Tradeoffs of Aquaculture
Disadvantages
Advantages
Large inputs of land, feed, And water
needed Produces large and concentrated outputs
of waste Destroys mangrove forests Increased
grain production needed to feed some
species Fish can be killed by pesticide runoff
from nearby cropland Dense populations
vulnerable to disease
Highly efficient High yield in small volume of
water Increased yields through cross- breeding
and genetic engineering Can reduce
over- harvesting Little use of fuel High
profits
Fig. 10-24, p. 226
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Commercial Fishing Methods
Spotter airplane
These methods are so effective that many fish
have become commercially extinct
Trawler fishing
Fish farming in cage
sonar
Purse-seine fishing
trawl flap
trawl lines
fish school
trawl bag
Drift-net fishing
Long line fishing
float
buoy
lines with hooks
fish caught by gills
Fig. 10-22, p. 225
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Protecting Food Resources

• Pest Management

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Pests

• Compete with humans for food
• Invade lawns and gardens
• Destroy wood in houses
• Spread disease
• Invade ecosystems
• Simply a nuisance
• May be controlled by natural enemies
• Humans too often destroy the natural enemies of
  pests

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Pesticides

• Pesticideschemicals to kill or control
  populations of organisms considered undesirable
  (insecticides, herbicides, fungicides, and
  rodenticides)
• Since 1950, pesticide use has increased 50 fold
  and are 10 times toxic (3/4 used in developed
  countries)
• Broad-spectrum agents are toxic to many species
• Selective or narrow-spectrum agents are effective
  against certain groups of organisms
• Persistencelength of time pesticides remain
  deadly in environment

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The Case for Pesticides

• Save human lives
• Increase food supplies and lower costs for
  consumers
• Profitable for farmers
• Work faster and better than alternatives
• When used properly, benefits exceed health risks
• Newer pesticides are safer and more effective
  than older ones
• Newer pesticides have low application rates

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The Case Against Pesticides

• Accelerate genetic resistance in pests
• The pesticide treadmill
• Kill the pests natural enemies
• Dont say put pollute
• May harm wildlife
• May threaten human health

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Pesticide Protection Laws in U.S.

• EPA banned or severely restricted the use of 57
  active pesticide ingredients between 1957 and
  2004, but studies show that laws are inadequate
  and poorly enforced by EPA, FDA, and USDA
• Other Ways to Control Pests
• Varying Cultivation practices
• rotating types of crops planted, adjusting
  planting times, and growing crops in areas where
  major pests do not exist, or use polyculture
  (plant diversity) so that pests either starve or
  get eaten by natural predators
• Genetic engineering
• create pest and disease resistant crops strains
• Sex Attractants
• lure pests into traps or attract natural
  predators of pests
• Use hormones that disrupt insects normal life
  cycle, restricting it from reaching puberty and
  reproducing
• Spray pests with hot water

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Integrated Pest Management

• Farmers develop a control program that includes
  cultivation (vacuuming up harmful bugs),
  biological (natural predators, parasites), and
  chemical methods applied in proper sequences and
  timing
• Effective and is a pollution prevention tactic
• However, it requires expert knowledge, acts
  slowly, and because it is costly (and the
  government subsidizes chemical pesticides) many
  farmers avoid it

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Strategies to promote IPM usage

• Add 2 sales tax on pesticides
• Set up federally supported IPM demonstration
  project on at least one farm in every county
• Train USDA field personnel and county farm agents
  IPM in order to help and teach it to farmers

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Sustainable Organic Agriculture

• Main ways to reduce hunger and malnutrition and
  harmful environmental effects of agriculture
• slow population growth
• reduce poverty so people can buy enough food for
  survival and good health
• develop sustainable organic agriculture
• produces roughly equal yields with lower carbon
  emissions, uses 30-50 less energy per unit of
  yield, improves soil fertility, reduces soil
  erosion, and more profitable

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Making the Transition to More Sustainable
Agriculture

• Greatly increase research on sustainable
  agriculture and improving human nutrition
• Set up demonstration projects so farmers can see
  how more sustainable organic agricultural systems
  work
• Provide subsidies and increased foreign aid to
  encourage its use
• Establish training programs in sustainable
  organic agriculture for farmers and govt
  agricultural officials, and create college
  curricula focused on these programs