BG/CH 0493 Environment and Sustainability
Chen Yuan
January 2015
1
Chapter 12: Food Production and the Environment
12-1 What is food security and why is it difficult to attain? 12-2 How is food produced? 12-3 What environmental problems arise from industrialized food production? 12-4 How can we protect crops from pests more sustainably? 12-5 How can we improve food security? 12-6 How can we produced food more sustainably?
2
Many people in less-developed countries have health problems from not getting enough food, while many people in more-developed countries suffer health problems from eating too much
The greatest obstacles to providing enough food for everyone are poverty, war, bad weather, climate change, and the harmful environmental effects of industrialized food production
12-1 What Is Food Security and Why Is It Difficult to Attain?
Food security
All or most people in a country have daily access to enough nutritious food to lead active and healthy lives
Food insecurity
Chronic hunger and poor nutrition
Causes:
Political upheaval, war, corruption, and bad weather
Poverty Is the Root Cause of Food Insecurity
Macronutrients Carbohydrates Proteins Fats
Micronutrients Vitamins Minerals
Chronic undernutrition Not enough food to meet basic energy needs
Chronic malnutrition Not enough protein or other key nutrients
Famine Severe shortage of food Result in mass starvation, many deaths, economic chaos, and social disruption
Many People Suffer from Chronic Hunger and Malnutrition
Most often vitamin and mineral deficiencies in people in less-developed countries
Vitamin A
Blind
Iron
Anemia
Iodine
Essential for thyroid function
Many People Do No Get Enough Vitamins and Minerals
Overnutrition Excess body fat from too many calories and not enough exercise
Similar health problems to those who are underfed
Lower life expectancy
Greater susceptibility to disease and illness
Lower productivity and life quality
Many People Have Health Problems from Eating Too Much
We have used high-input industrialized agriculture and lower-input traditional agriculture to greatly increase food supplies
Three systems produce most of our food Croplands
Rangelands, pastures, and feedlots 16% on 29% of
Aquaculture 7%
Three main grain crops wheat, rice, and corn
Irrigation supply of water to crops
12-2 How Is Food Produced?
Industrialized agriculture Heavy equipment Large amounts of financial capital, fossil fuels, water, commercial fertilizers, and pesticides Single crop
Goal is to steadily increase crop yield Plantation agriculture cash crops
Primarily in less-developed countries
Increased use of greenhouses to raise crops
Industrialized Crop Production Relies on High-Input Monocultures
Fig. 12-7a, p. 283
Industrialized Agriculture
Uses synthetic inorganic fertilizers and sewage sludge to supply plant nutrients
Makes use of synthetic chemical pesticides
Uses conventional and genetically modified seeds
Depends on nonrenewable fossil fuels (mostly oil and natural gas)
Produces significant air and water pollution and greenhouse gases
Is globally export-oriented
Uses antibiotics and growth hormones to produce meat and meat products
Traditional subsistence agriculture Human labor and draft animals for family food
Traditional intensive agriculture Higher yields through use of manure and water
Polyculture Crop diversity Benefits over monoculture
Slash-and-burn agriculture Subsistence agriculture in tropical forests Clear and burn a small plot Grow many crops that mature at different times Reduced soil erosion Less need for fertilizer and water
Traditional Agriculture Often Relies on Low-Input Polycultures
Crops grown with ecologically sound and sustainable methods
No synthetic pesticides or fertilizers
Has a number of environmental advantages
Usually produces less than conventional agriculture
Organic Agriculture Is on the Rise
Fig. 12-7b, p. 283
Organic Agriculture
Emphasizes prevention of soil erosion and the use of organic fertilizers such as animal manure and compost, but no sewage sludge to help replace lost plant nutrients
Employs crop rotation and biological pest control
Uses no genetically modified seeds
Reduces fossil fuel use and increases use of renewable energy such as solar and wind power for generating electricity
Produces less air and water pollution and greenhouse gases
Is regionally and locally oriented
Uses no antibiotics or growth hormones to produce meat and meat products
Green Revolution increase crop yields Monocultures of high-yield key crops
Rice, wheat, and corn
Large amounts of fertilizers, pesticides, water Multiple cropping
Second Green Revolution Fast growing dwarf varieties
World grain has tripled in production
A Closer Look at Industrialized Crop Production
First gene revolution
Cross-breeding through artificial selection
Slow process
Amazing results
Genetic engineering second gene revolution
Genetic modified organisms (GMOs) transgenic organisms
Crossbreeding/Genetic Engineering Produce New Varieties of Crops/Livestock
Animals for meat raised in: Pastures and rangelands Feedlots
Meat production increased more than sixfold between 1950 and 2010
Increased demand for grain Demand is expected to go higher
Meat Production Has Grown Steadily
Fishery Concentration of a particular species suitable for commercial harvesting
30% are overfished
57% harvested at full capacity
Aquaculture, blue revolution -growing type of food production
Dominated by operations that raise herbivorous species
Fish and Shellfish Production Have Increased Dramatically
Fig. 12-12, p. 287
140
100
120
80 Wild catch
Pro
du
cti
on
(m
illi
on
s o
f m
etr
ic t
on
s)
40
60
0
20 Aquaculture
Year Total World Fish Catch
1950 1960 1970 1990 2000 2010 1980 2020
Grow, store, process, package, transport, refrigerate, and cook (10 times of the food energy)
Mostly nonrenewable energy oil and natural gas
Agriculture uses 20% of all energy use in the U.S.
Amount of energy per calorie used in the U.S. has declined 50% since the 1970s
Industrialized Food Production Requires Huge Inputs of Energy
Future food production may be limited by soil erosion and degradation, desertification, irrigation water shortages, air and water pollution, climate change, and loss of biodiversity Producing Food Has Major Environmental Impacts. Agriculture has harmful affects on:
Biodiversity Soil Water Air Human health
12-3 What Environmental Problems Arise from Food Production?
Fig. 12-13, p. 288
Natural Capital Degradation
Food Production
Biodiversity Loss Soil Water Air Pollution Human Health
Erosion Emissions of greenhouse gas CO2 from fossil fuel use N2O from inorganic fertilizer use, and methane (CH4) from cattle
Nitrates in drinking water (blue baby)
Loss of fertility
Aquifer depletion
Pesticide residues in drinking water, food, and air Salinization
Increased runoff, sediment pollution, and flooding from cleared land Fish kills from
pesticide runoff
Waterlogging Killing wild predators to protect livestock
Desertification
Pollution from pesticides and fertilizers
Loss of genetic agrobiodiversity replaced by monoculture strains
Algal blooms and fish kills caused by runoff of fertilizers and farm wastes
Bacterial contamination of meat
Other air pollutants from fossil fuel use and pesticide sprays
Conversion of
grasslands, forests,
and wetlands to
crops or rangeland
Livestock wastes
in drinking and
swimming water
Soil erosion Movement of soil by wind and water Natural causes Human causes
Two major harmful effects of soil erosion Loss of soil fertility Water pollution
Topsoil Erosion Is a Serious Problem in Parts of the World
Stepped Art
Stable or
nonvegetative
Serious concern
Some concern
Fig. 12-16, p. 289
Desertification Productive potential of topsoil falls by 10% or more
Prolonged drought, human activities
Human agriculture accelerates desertification
Dust bowl Severe wind erosion of topsoil
Drought and Human Activities Are Degrading Drylands
Soil salinization Gradual accumulation of salts in the soil from irrigation water
Lowers crop yields and can even kill plants
Affects 10% of world croplands
Waterlogging Irrigation water gradually raises water table
Can prevent roots from getting oxygen
Affects 10% of world croplands
Excessive Irrigation Has Serious Consequences
Fig. 12-18, p. 292
Top Related