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Food, Soil, and Pest Management

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Title: Food, Soil, and Pest Management


1
Food, Soil, and Pest Management
  • Chapter 10
  • Morgan Green, James Lasky, Ryan McClain

2
Food Production
  • Can we produce enough food to meet the rising
    population and reduce poverty without degrading
    our croplands?

3
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

4
Bugs as Food
Fig. 10-1, p. 206
5
Industrialized vs. Traditional Food Production
  • (Crop Lands 77 of worlds food, Rangelands 16,
    Oceanic fisheries 7)

6
  • 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

7
  • 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

8
Principal Types of Food Production
Industrialized agriculture
Plantation agriculture
Intensive traditional agriculture
Fig. 10-3, p. 208
Shifting cultivation
Nomadic herding
No agriculture
9
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

10
  • 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

11
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
12
Agricultural techniques and their effects
13
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

14
Land Degradation
  • natural or human induced processes decrease the
    ability of land to support crops

15
Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 223
16
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

17
Soil Erosion on Irrigated Cropland
Fig. 10-8, p. 212
18
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

19
World Desertification
Moderate
Severe
Very Severe
Fig. 10-11, p. 214
20
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

21
Salinization and Waterlogging in Soils
Transpiration
Evaporation
Evaporation
Evaporation
Waterlogging
Less permeable clay layer
Fig. 10-13, p. 215
22
Salinization from Heavy Irrigation
Fig. 10-14, p. 215
23
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

24
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

25
Terracing
Fig. 10-16a, p. 217
26
Contour Planting and Strip Cropping
Fig. 10-16b, p. 217
27
Alley Cropping
Fig. 10-16c, p. 217
28
Windbreaks
Fig. 10-16d, p. 217
29
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

30
Food production, nutrition, and environmental
effects
31
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

32
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

33
Increasing Food Production
  • Crossbreeding and Genetic Engineering

34
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
35
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

36
Overgrazing
  • Occurs when too many animals graze and exceed the
    carrying capacity of a grassland.
  • Results
  • Soil erosion
  • Desertification
  • Lowered NPP of grassland vegetation

37
Overgrazed and Lightly Grazed Rangeland
Fig. 10-20, p. 223
38
Acquacultures
  • the cultivation of aquatic populations under
    controlled conditions.

39
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
40
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
41
Protecting Food Resources
  • Pest Management

42
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

43
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

44
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

45
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

46
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

47
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

48
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

49
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

50
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
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