Sustainable Agriculture The environmental imperative of Sustainable Agriculture The Future of Food.
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Transcript of Sustainable Agriculture The environmental imperative of Sustainable Agriculture The Future of Food.
Concept The greatest
obstacles to providing enough food for everyone are poverty, political upheaval, corruption, war, and the harmful environmental effects of food production.
The challenge of feeding a growing population
What Is Food Security and Why Is It So Difficult to Attain?
Concept Many of the poor have health problems from
not getting enough food, while many people in affluent countries suffer health problems from eating too much.
Food
About 925 million people have health problems because they do not get enough to eat
1.6 billion people face health problems from eating too much.
Over-nutrition Too many calories, too
little exercise, or both Similar overall health
outlook as undernourished
66% of American adults overweight
34% obese Heart disease and
stroke Type II diabetes and
some cancers
Over nutrition Food intake exceeds energy use and causes
body fat Too many calories not enough exercise Lower life expectancy, heart disease, lower
productivity and quality of life In developed countries it is 2nd leading
preventable cause of death after smoking
Malnutrition UN Estimates: Annually, 5.5
million children die prematurely due to effects of under nutrition.
In U.S. estimates are 11 million do not have access to enough food
Concept We have used
high-input industrialized agriculture and lower-input traditional methods to greatly increase supplies of food
Modern industrialized agriculture has a greater harmful impact on the environment than any other human activity.
What are the environmental impacts of our food choices?
Environmental Effects of Food Production
Biodiversity loss Soil degradation Air pollution Water shortages
and erosion Human health
Green Revolution Attributed to Norman Borlaug,
American scientist Conducted research in Mexico Developed new disease resistance
high-yield varieties of wheat. By combining Borlaug's wheat
varieties with new mechanized agricultural technologies, Mexico was able to produce more wheat than was needed, leading to its becoming an exporter of wheat by the 1960s.
Prior to the use of these varieties, the country was importing almost half of its wheat supply.
Green Revolution The technologies spread
worldwide in the 1950s and 1960s.
The U.S. imported about half of its wheat in the 1940s but after using Green Revolution technologies, became an exporter by the 1960s.
The Rockefeller Foundation and the Ford Foundation, as well as many government agencies around the world funded increased research.
Green Revolution India was on the brink of mass
famine in the early 1960s because of its rapidly growing population.
Borlaug and the Ford Foundation implemented research there and developed a new variety of rice, IR8, that produced more grain per plant when grown with irrigation and fertilizers.
Today, India is one of the world's leading rice producers and IR8 rice usage spread throughout Asia.
Green Revolution Along with the new
strains of wheat, rice and corn, GR required Synthetic fertilizer and
pesticides Increased water and
fossil fuel consumption Leading to
Localized pollution Soil erosion Salinization Desertification
Green Revolution Monocultures: large
expanses of single crop types
Replaced traditional, small-scale polycultures
More efficient for planting and harvesting
Increased risk of crop failure due to disease
Food Production Global food production
has risen more quickly than world population over the past half-century
Between 1960-2008 food production rose 150%
Between the same years, population rose 100%
Land area converted to agriculture increased only 10%
Seed Bank Seed banking involves
collecting and storing seed from plants.
It is both an insurance policy against extinction and a source of high-quality material for the restoration of habitats.
Labor intensive Estimated an average
of $5000 is needed to save a species from extinction.
The Millennium Seed BankWakehurst, England Largest ex situ plant conservation project in the
world. Focus on global plant life faced with the threat of
extinction and plants of most use for the future. Partner with 50 countries. Successfully banked 10% of the world's wild
plant species. Goal is 25% by 2020 Target plants and regions most at risk from
climate change and the ever-increasing impact of human activities.
Svalbard Global Seed Vault Spitsbergen, Norway. On 10 March 2010
the seed count at the vault passed half a million (500,000) samples. As of July 2012, the number of distinct samples has increased to 750,000.
Main focus is food crops
The Sierra de Manantlan Biosphere Reserve
Southern Mexico Repository for crop
biodiversity, especially corn.
Preserving traditional varieties in their ancestral homelands
Can We Continue to Produce MORE? Crossbreeding and
artificial selection Genetic engineering
(gene splicing) Genetically modified
organisms (GMOs) Continued Green
Revolution techniques
Introducing new foods
Working more land
Cross Breading and Artificial Selection
Done for centuries to produce “improved” crops
Bigger corn and tomatoes
Slow process
Genetic Engineering Slicing the DNA of one
species into another Quicker More cost efficient Allows insertion of
almost any species More than 2/3 of foods
in U.S. have GE ingredients
Improvements drought, pests, salty
soil, less fertilizer………
Can We Continue to Produce MORE?
Lack of resources such as water, fertile soil and environmental factors may limit our ability to continue to yield more crops.
Can we just spread the “Green Revolution” around the world to produce more?
Will GE uniformity lead to more vulnerable crops to pests, diseases, harsh weather?
Can We Continue to Produce MORE?
Will people be willing to try new foods? (superfoods)
Is irrigating more land the answer?
Is cultivating more land the answer?
Can we grow more food in urban areas?
Why not just waste less food? 70% currently wasted
How are rangelands used to produce meat?
Is producing more meat the answer to the world’s food problems?
What are the effects of overgrazing?
How can meat be produced more sustainable?
Environmental issues of raising animals for food
Producing More Meat
Many feel need to increase meat production to feed population
As incomes rise so does meat consumption
Meat Industry is a powerful lobby
Jobs, jobs, jobs…
Producing More Meat
Global meat production has increased fivefold since 1950
Per capita meat production has doubled since 1950
Feedlots: animals are fattened for slaughter in densely populated confined areas
Producing More Meat
Concentrated animal feeding operations (CAFO)
High density Minimize land cost Improve feeding
efficiency
Producing More Meat
One-third of the world’s cropland is devoted to growing feed for animals
45% of global grain production goes to livestock and poultry
High Density Farming Leads to Problems Surface and
ground water contamination
Disease Antibiotic and
hormone use Greenhouse
gases Waste disposal
Rangelands
Cattle, Sheep, goats are on 42% of rangeland
Pastures are managed grasslands
Renewable resource
Threat to native plant species?
Overgrazing Occurs when too
many animals graze for too long and exceed the carrying capacity of the grassland area
Kills vegetation Reduces grass cover Causes erosion Compacts soil Damages watershed Desertification
Overgrazing Solutions Control numbers by
figuring out carrying capacity
Move from riparian zones and locate watering hole away from sensitive zones
Move animals around
Replant overgrazed areas and/or use fertilizers
Kilograms of grain needed per kilogram of body weightKilograms of grain needed per kilogram of body weight
Beef cattleBeef cattle 2020
PigsPigs 7.37.3
ChickenChicken 2.82.8
MilkMilk 1.11.1
Efficiency of converting grain to animal protein
More Fish?• Where do we get our fish
and shellfish?• What are the impacts of
over fishing?• What is aquaculture?
Where do we get fish and shellfish?Fisheries: concentrations of
aquatic species suitable for harvesting from a body of water
55% come from the ocean Fish and shellfish supply
7% of world’s food Mostly from coastal zones Primary source of protein
for more than 1 billion people (mostly developing countries)
How are fish harvested?
High Tech Global Fishing Fleets Roam World Sonar, GPS, spotter
planes, huge nets, long fishing lines
Large factory ships catch, process and freeze product
How are fish harvested? Trawling: dragging a
funnel shaped net along bottom of sea
Used to catch bottom dwellers
Shrimp, cod, flounder, scallops
Scrapes up everything on bottom leaving it bare
Clear cutting ocean floor
Bycatch thrown back
How are fish harvested? Purse-Seine Fishing:
Surrounding schools of fish with boats and a huge net to capture entire school
Net drawn in tighter and tighter
Tuna, herring, mackerel
Uses spotter planes often
Led to huge dolphin kills
How are fish harvested? Long lining: putting
out lines up to 80 miles long with thousands of hooks
Swordfish, tuna, shark, halibut, cod
Huge bycatch Endanger turtles,
dolphins, whales etc.
How are fish harvested? Drift netting: using
huge nets to trap fish
Huge bycatch Kill many unwanted
species Danger to marine
mammals Since 1992 UN ban
driftnets over 1.6 miles in international water (voluntary compliance)
Overfishing Tragedy of Commons Not a new problem,
but becoming global and tech driven
Commercial Extinction Adding to the problem
development along the coasts
wetland and estuary pollution
coral reef and mangrove forest destruction
New high demand for “healthy” fish
Where do we get fish and shellfish?Aquaculture: using feedlot
management to raise marine and freshwater fish.
Using cages and nets Rivers, lakes and
oceans China is the world’s
leader 1/3rd of world’s marine
fish harvest is used for animal feed, fishmeal and oil
AquacultureRaising fish and shellfish for food, like crops World’s fastest
growing food production
What do you think are pros and cons of this technique?
AquaculturePros
Highly efficient High yield in small volume
of water Increased yields through
crossbreeding and genetic engineering
Can reduce overharvesting of conventional fisheries
Little use of fuel Profits not tied to price of
oil High profits
Cons
Large inputs of land, feed and water needed
Produces large and concentrated outputs of waste
Destroys mangrove forests Increased grain production
needed to fee some species Fish can be killed by
pesticide runoff Dense populations
vulnerable to disease Tanks too contaminated to
use after about 5 years.
Solutions: Sustainable Agriculture
Concept More sustainable
forms of food production will greatly reduce the harmful environmental impacts of current systems while increasing food security and national security for all countries.
Is Organic Agriculture the Answer?
Many environmental advantages over conventional farming
Requires more human labor
Organic food costs 10-75% more than conventionally grown food
Cheaper than conventionally grown food when environmental costs are included
Organic Agriculture Organic agriculture as a component of
sustainable agriculture Certified organic farming:
Less than 1% of world cropland 0.1% of U.S. cropland 6-18% in many European countries
Sustainable AgricultureMore
High yield polyculture Organic fertilizers Biological pest control Integrated pest
management Irrigation efficiency Perennial crops Crop rotation Use of more water efficient
crops Soil conservation Subsidies for more
sustainable farming and fishing
Less Soil erosion Soil salinization Aquifer depletion Overgrazing Overfishing Loss of biodiversity Loss of prime cropland Food waste Subsidies for
unsustainable farming and fishing
Population growth poverty
Governments influence food production
Provide subsidies to farmers Price supports, tax
breaks to encourage food production
Can harm farmers in other countries who don’t get subsidies
Some analysts call for ending all subsidies
Let the marketplace decide