Food Security: The Challenge of Feeding 9 Billion People

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Science  12 Feb 2010:
Vol. 327, Issue 5967, pp. 812-818
DOI: 10.1126/science.1185383


  • Fig. 1

    Changes in the relative global production of crops and animals since 1961 (when relative production scaled to 1 in 1961). (A) Major crop plants and (B) major types of livestock. [Source: (2)]

  • Fig. 2

    An example of a major successful sustainable agriculture project. Niger was strongly affected by a series of drought years in the 1970s and 1980s and by environmental degradation. From the early 1980s, donors invested substantially in soil and water conservation. The total area treated is on the order of 300,000 ha, most of which went into the rehabilitation of degraded land. The project in the Illela district of Niger promoted simple water-harvesting techniques. Contour stone bunds, half moons, stone bunding, and improved traditional planting pits (zaı¨) were used to rehabilitate barren, crusted land. More than 300,000 ha have been rehabilitated, and crop yields have increased and become more stable from year to year. Tree cover has increased, as shown in the photographs. Development of the land market and continued incremental expansion of the treated area without further project assistance indicate that the outcomes are sustainable (51, 52).

  • Fig. 3

    Makeup of total food waste in developed and developing countries. Retail, food service, and home and municipal categories are lumped together for developing countries. [Source: (16, 3739)]


  • Table 1

    Examples of current and potential future applications of GM technology for crop genetic improvement. [Source: (18, 49)]

    Time scaleTarget crop traitTarget crops
    CurrentTolerance to broad-spectrum
    Maize, soybean, oilseed
    Resistance to chewing insect
    Maize, cotton, oilseed
    (5–10 years)
    Nutritional bio-fortificationStaple cereal crops, sweet
    Resistance to fungus and virus
    Potato, wheat, rice, banana,
    fruits, vegetables
    Resistance to sucking insect pestsRice, fruits, vegetables
    improved processing and storageWheat, potato, fruits,
    Drought toleranceStaple cereal and tuber crops
    (10–20 years)
    Salinity toleranceStaple cereal and tuber crops
    Increased nitrogen-use
    High-temperature tolerance
    (>20 years)
    apomixisStaple cereal and tuber crops
    Nitrogen fixation
    Denitrification inhibitor
    Conversion to perennial habit
    Increased photosynthetic efficiency
  • Table 2

    Comparison of the impact of grazing and intensive (confined/industrialized) grain-fed livestock systems on water use, grain requirement, and methane production. Service water is that required for cleaning and washing livestock housing and other facilities. Dashes indicate combinations for which no data are available (either because it cannot be measured or because the combination does not exist). This table does not include other impacts of differing livestock management systems such as (i) nutrient run-off and pollution to surface and groundwater, (ii) protozoan and bacterial contamination of water and food, (iii) antibiotic residues in water and food, (iv) heavy metal from feed in soils and water, (v) odor nuisance from wastes, (vi) inputs used for feed production and lost to the environment, (vii) livestock-related land-use change. [Source: (7, 50)]

    WaterMeasure of water useGrazingIntensive
    Liters day–1 per animal at 15°C
    CattleDrinking water: all22103
    Service water: beef511
    Service water: dairy522
    Pigs (lactating adult)Drinking water1717
    Service water25125
    Sheep (lactating adult)Drinking water99
    Service water55
    Chicken (broiler and layer)Drinking water1.3–1.81.3–1.8
    Service water0.09–0.150.09–0.15
    Feed required to produce 1 kg of meatkg of cereal per animal
    Chicken (broiler)1
    Methane emissions from cattlekg of CH4 per animal year–1
    Cattle: dairy (U.S., Europe)117–128
    Cattle: beef, dairy (U.S., Europe)53–60
    Cattle: dairy (Africa, India)45–58
    Cattle: grazing (Africa, India)27–31

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