Miller Ch 12 B

							         Miller Chapter 12



FOOD, SOIL, AND PEST MANAGEMENT
HOW CAN WE PROTECT CROPS FROM PESTS
MORE SUSTAINABLY?

   We can sharply cut pesticide use without
    decreasing crop yields by using a mix of
    cultivation techniques, biological pest controls,
    and small amounts of selected chemical
    pesticides as a last resort (integrated pest
    management).
    NATURE CONTROLS THE POPULATIONS OF
    MOST PESTS
 What is a pest – interferes with human welfare
 Natural enemies—predators, parasites, disease
  organisms—control pests
     In natural ecosystems
     In many polyculture

     agroecosystems
WE USE PESTICIDES TO TRY TO CONTROL
PEST POPULATIONS
   Pesticides
     Insecticides– insects killers
     Herbicides – weed killers

     Fungicides – fungus killers

     Rodenticides – rat and mouse killers

   Herbivores overcome plant defenses through
    natural selection: coevolution
WE USE PESTICIDES TO TRY TO CONTROL
PEST POPULATIONS
 First-generation pesticides-natural chemicals from
  plants
 Second-generation pesticides
     Paul Muller: DDT Nobel Prize 1948
     Benefits versus harm
 Broad-spectrum agents – toxic to many pests and
  non-pest species. Chlorinated hydrocarbons: DDT,
  organophosphates : malathion, parathion
 Selective or narrow spectrum agents -
 Persistence – length of time they remain deadly in
  the environment for years, biologically magnified in
  food webs
INDIVIDUALS MATTER: RACHEL CARSON
 Biologist : DDT use
  was increasing to
  control mosquitoes
 Silent Spring - 1962

 Potential threats of
  uncontrolled use of
  pesticides
 Gave impetus to the
  US environmental
  movement
    MODERN SYNTHETIC PESTICIDES HAVE
    SEVERAL ADVANTAGES
   Save human lives prevented deaths from malaria,
    typhus and bubonic plague : at least 7 million people

   Increases food supplies and profits for farmers
    protect 55% of the world’s food supply. Profit $1:$4

   Work quickly, long shelf life, easily shipped and
    applied

   Health risks are very low relative to their benefits

   New pest control methods: safer and more effective
MODERN SYNTHETIC PESTICIDES HAVE
SEVERAL DISADVANTAGES

   Accelerate the development of genetic resistance, 5
    to 10 years, sooner in the tropics

   Financial treadmill

   Kill natural predators and parasites that help control

   Only 0.1-2% of the pesticide applied by aerial or
    ground spraying reaches the target pest. Rest
    pollutes air, water, harm wild life, affect human
    health
MODERN SYNTHETIC PESTICIDES HAVE
SEVERAL DISADVANTAGES
   David Pimentel: Pesticide use has not reduced U.S.
    crop loss to pests
      Loss of crops is about 31%, even with 33-fold
       increase in pesticide use
      High environmental, health, and social costs with
       use, $5-10 in damages for every $1 spent
      Use alternative pest management practices could
       halve the use of chemical pesticides on 40 major
       US crops
   Pesticide industry refutes these findings
   Campbell soup tomatoes in Mexico, Rice in Indonesia,
    Sweden
GLYPHOSATE-RESISTANT CROP WEED
MANAGEMENT SYSTEM: A DILEMMA
   Best-selling herbicide (Roundup), Monsanto

   Advantages – does not harm living things, degrades
    into harmless substances within weeks

   Disadvantages - resistant weeds , expensive to develop
    other pesticides
CASE STUDY: ECOLOGICAL SURPRISES
   1955: Dieldrin sprayed to control mosquitoes

   Malaria was controlled

   Dieldrin didn’t leave the food chain

   Domino effect of the spraying

   Happy ending
    LAWS AND TREATIES CAN HELP TO PROTECT US
    FROM THE HARMFUL EFFECTS OF PESTICIDES
   U.S. federal agencies
     EPA
     USDA
     FDA

 Effects of active and inactive pesticide ingredients
  are poorly documented
 Circle of poison, boomerang effect – residues of
  banned chemicals exported to other countries may
  come back on food, winds carry persistent
  pesticides such as DDT
INTERNATIONAL TREATIES

 1998 – 50 countries developed treaty that
  requires exporting countries to have consent
  from importing countries for exports of 22
  pesticides , 5 industrial chemicals
 2000 – 100 countries signed to phase out 12
  of the most hazardous persistent organic
  pollutants (POP’s), 9 of them hydrocarbons
  (DDT)
 United States has not signed this agreement
                             ALTERNATIVES TO USING
   Fool the pest : rotate
    crops, adjust plant
                             PESTICIDES
    times
   Provide homes for
    pest enemies
   Implant genetic
    resistance : GMO’s
   Bring in natural
    enemies : natural
    predators
   Use insect perfumes
   Hormones
   Scald them
INTEGRATED PEST MANAGEMENT IS A
COMPONENT OF SUSTAINABLE AGRICULTURE
   Integrated pest
    management (IPM)
     Coordinate:  cultivation,
      biological controls, and
      chemical tools to
      reduce crop damage to
      an economically
      tolerable level
   Disadvantages
     expert   knowledge
USE GOVERNMENT POLICIES TO IMPROVE FOOD
PRODUCTION AND SECURITY
 Control prices – keep artificially low
 Provide subsidies – price supports, tax breaks,
  subsidies for 31% of global farm income
     Developed  : $280 billion /year
     Substitute traditional subsidies with ones that
      promote sustainable farming practices
     Subsidies to fishing – promotes destructive fishing
      practices
   Let the marketplace decide
USE GOVERNMENT POLICIES TO IMPROVE FOOD
PRODUCTION AND SECURITY

   United Nations Children’s Fund (UNICEF)
    suggests these measures. Can be done at an
    average annual cost of $5-10 / child
     Immunizing  children against childhood diseases
     Encourage breast-feeding
     Prevent dehydration in infants and children
     Prevent blindness – Vitamin A capsule (75c/child)
     Provide family planning services
     Increase education for women
HOW CAN WE PRODUCE FOOD MORE
SUSTAINABLY?
   Sustainable food production will require
    reducing topsoil erosion, eliminating
    overgrazing and overfishing, irrigating more
    efficiently, using integrated pest management,
    promoting agrobiodiversity, and providing
    government subsidies for more sustainable
    farming, fishing, and aquaculture.
HOW CAN WE PRODUCE FOOD MORE
SUSTAINABLY?
    Producing enough food to feed the rapidly
    growing human population will require growing
    crops in a mix of monocultures and poly
    cultures and decreasing the enormous
    environmental impacts of industrialized food
    production.
   Soil conservation,
    some methods             REDUCE SOIL EROSION
       Terracing
       Contour planting
       Strip cropping
        with cover crop
       Alley cropping,
        agroforestry
       Windbreaks or
        shelterbeds
       Conservation-
        tillage farming
          No-till
          Minimum tillage



   Identify erosion
    hotspots
SOLUTIONS: MIXTURE OF MONOCULTURE CROPS
PLANTED IN STRIPS ON A FARM
RESTORE SOIL FERTILITY
   Organic fertilizer
      Animal manure – dung , urine
      Green manure – freshly cut, growing green vegetation
      Compost microorganisms to break down organic waste
   Commercial inorganic fertilizer active ingredients
      Nitrogen
      Phosphorous
      Potassium


    Crop Rotation
REDUCE SOIL SALINIZATION AND
DESERTIFICATION
   Soil salinization
       Prevention
       Clean-up
                                                         Flush soil
                                                         (expensive and
   Desertification,            Reduce irrigation
                                                         wastes water
    reduce
                                                         Stop growing
       Population growth                                crops for 2–5
       Overgrazing             Switch to salt-          years
       Deforestation           tolerant crops (such
                                as barley, cotton, and
                                                         Install
       Destructive forms of    sugar beet
                                                         underground
                                                         drainage
        planting, irrigation,                            systems
        and mining                                       (expensive)
SHIFT TO MORE SUSTAINABLE AGRICULTURE

   Paul Mader and David Dubois
            study
     22-year

     Compared organic and conventional farming



   Benefits of organic farming
     littleor no use of synthetic pesticides, fertilizers or
      genetically engineered seeds, fields free for 3 years
     livestock raised without genetic engineering
SOLUTIONS
       Organic Farming
Improves soil fertility
Reduces soil erosion
Retains more water
in soil during
drought years
Uses about 30% less
energy per unit of yield
Lowers CO2 emissions
Reduces water pollution
by recycling livestock
wastes
Eliminates pollution
from pesticides
Increases biodiversity
above and below ground
Benefits wildlife such
as birds and bats
                           Fig. 12-32, p. 308
SCIENTISTS ARE STUDYING BENEFITS AND
COSTS OF ORGANIC FARMING

   Effect of different fertilizers on nitrate leaching
    in apple trees
     calcium nitrate and alfalfa residues, composted
      chicken manure, integrated approach (combined)


   Less nitrate leached into the soil after organic
    fertilizers were used – 4.4 to 5.6 times less
COMPARISON OF THE ROOTS BETWEEN AN ANNUAL
PLANT AND A PERENNIAL PLANT




                              Roots of a tall grass
Annual Wheat
                                 prairie plant
 Crop Plant


                                Better at using
                              water and nutrients
BUY LOCALLY GROWN FOOD ……………………

 Supports local economies
 Does not have to be transported far – reduces
  greenhouse gas emissions, 5 to 17 times less
 Reduces environmental impact on food
  production – grow organic food or buy organic
  food grown locally
 Community-supported agriculture (CSA)