Transcript Slide 1

CP551 Sustainable Development
“In the end we will conserve only
what we love;
we will love only what we understand;
and
we will understand only what we
have been taught.”
– Baba Dioum
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07 Jan 2012
Module 8:
Use of fertilizers and pesticides,
green revolution,
and agricultural biotechnology
in the agricultural sector,
and their impact on
sustainable development.
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07 Jan 2012
Paddy Production in Sri Lanka 1952 - 2006
4,500
4,000
3,500
Average Yield (kg / hect.)
increased 2.6 times
3,000
2,500
2,000
Production (in ‘000 Tonnes)
increased 5.5 times
1,500
1,000
500
0
1950
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Harvested area (in ‘000 hect.)
doubled
1960
1970
1980
1990
2000
2010
http://www.statistics.gov.lk/agriculture/Paddy%20Statistics/
TB3_NP_Annual_1952_2006.pdf
Fact:
Average yield of paddy per area in Sri Lanka
increased by a factor of 2.6 during 1952 to 2006,
which keeps pace with
the Sri Lanka population increase by a factor of
2.37 during 1950 to 2005.
How was it possible?
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http://www.statistics.gov.lk/ and http://esa.un.org/unpp/p2k0data.asp
Ploughing
in 2007
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Sowing
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Weed &
Pest
control
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Harvesting
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What helped to increase
Sri Lanka’s paddy
production by a factor of
2.6 during 1952 to 2006?
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Take a look at the Global Agriculture
between 1960 and 2000:
– world population doubled from 3 to 6 billion people
– global economy increased more than sixfold
to meet this demand:
–
–
–
–
food production increased 2 ½ times
water use doubled
wood harvests for pulp and paper production tripled
timber production increased by more than half
Who is eating?
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07 Jan 2012
http://www.millenniumassessment.org/
Population Undernourished
(% of total population)
1990s
2000s
Medium Human Development
20
16
Low Human Development
36
34
High Human Development
High Income
Middle Income
Low Income
World
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HDR2007/2008
Population Undernourished
(% of total population)
1990s
2000s
Medium Human Development
20
16
Low Human Development
36
34
Middle Income
14
11
Low Income
28
24
High Human Development
High Income
World
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HDR2007/2008
Population Undernourished
(% of total population)
1990s
2000s
Medium Human Development
20
16
Low Human Development
36
34
Middle Income
14
11
Low Income
28
24
World
20
17
High Human Development
High Income
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HDR2007/2008
Population Overweight
(% of total population)
Body Mass Index (BMI) =
Overweight
BMI ≥ 25.00
weight (in kg)
height2 (in m2)
Pre-obese
Obese
BMI =
25.00 - 29.99
BMI ≥ 30.00
World Data Table is under construction
By World Health Organizations
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07 Jan 2012
http://www.who.int/mediacentre/factsheets/fs311/en/index.html
Obese adults in population (%)
30 to 40%
20 to 30%
10 to 20%
5 to 10%
0 to 5%
No data
BMI (in kg / m2) > 30
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– Food production
has more than
doubled since
1960
– Food production
per capita has
grown
– Food price has
fallen
– Undernourished
in developing
countries have
fallen
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07 Jan 2012
Source: http://www.millenniumassessment.org/
It is good to have increased the food production
which might have helped reducing
the number of undernourished people.
The first of the Millennium Development Goals (MDGs)
is to
Eradicate Extreme Poverty and Hunger
The seventh of the MDGs is to
Ensure Environmental Sustainability
How to achieve both the goals
simultaneously?
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07 Jan 2012
Green Revolution:
Green Revolution of the 20th century
- transformed agriculture that led (in some places) to
significant increases in agricultural production (between
the 1940s and 1960s).
- made food production to match with the global
population growth.
- has had major social and ecological impacts.
Medieval Green Revolution
or the Arab Agricultural Revolution of the 8th century
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Source: http://en.wikipedia.org/wiki/Green_Revolution
Green Revolution:
President Mahinda
Rajapaksa greets
Prof. M.S. Swaminathan,
who is considered the
Father of the
Indian Green Revolution.
?
Green Revolution of the 21st century
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07 Jan 2012
Green Revolution:
in India
- High-yielding varieties of seeds of wheat, rice, and
other grains that had been developed in Mexico and in the
Philippines were introduced in India after 1965
- Use of synthetic fertilizers, irrigation and pesticide/
herbicide increased
- Increased production made India self-sufficient in food
grains
- Famine in India, once accepted as inevitable, has not
returned since the introduction of Green Revolution crops.
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07 Jan 2012
Source: http://en.wikipedia.org/wiki/Green_Revolution
Green Revolution:
Is food production actually
related to famine?
Prof. Amartya Sen claimed
famines such as the Bengal
Famine of 1943 (about 4 million
people died) were not caused by
decreases in food supply, but by
socioeconomic dynamics and a
failure of public action.
Economist Peter Bowbrick has
accused Sen of misrepresenting
historical data, telling outright lies and
being wrong on his theory of famines.
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07 Jan 2012
Nobel Prize in
Economics (1998)
Source: http://en.wikipedia.org/wiki/Green_Revolution
Green Revolution:
- introduced high-yielding varieties of seeds that are
often developed elsewhere
- increased the use of pesticide/herbicide which were
necessary to limit the high levels of pest damage that
inevitably occur in monocultures
- increased the use of synthetic fertilizers
- increased dependence on fossil fuels from which
pesticides, herbicides and synthetic fertilizers are produced
- increased the use of irrigation (which has created
significant problems of arsenic contamination, salinization,
waterlogging, and lowering of water tables in certain areas)
- affected both agricultural and wild biodiversities
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07 Jan 2012
Source: http://en.wikipedia.org/wiki/Green_Revolution
Green Revolution:
Socioeconomic
impacts
- it required the purchase of fertilisers, irrigation pumps and
regular fresh supplies of seed
- smaller farmers often went into debt, which in many cases
result in a loss of their farmland
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07 Jan 2012
Source: http://en.wikipedia.org/wiki/Green_Revolution
Green Revolution:
A country could go from importing food to
exporting it
seen by some as committing ecological and
economic "suicide"
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Fertilizer Use:
Growing crops need
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carbon (C),
hydrogen (H),
oxygen (O),
energy, and
other nutrients
Fertilizer Use:
Air gives C as CO2; O as O2; H as water vapour
Water gives H
Sunlight gives energy
Soil gives other essential nutrients
Major nutrients:
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Sulphur (S)
Calcium (Ca)
Magnesium (Mg)
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Minor nutrients:
Iron (Fe)
Molybdenum (Mo)
Boron (B)
Copper (Cu)
Manganese (Mn)
Zinc (Zn)
Chlorine (Cl)
and others…
Fertilizer Use:
With high yielding varieties of crops,
most soils are unable to supply the
needed amounts of plant nutrients.
Fertilizers are chemicals that supply
plant nutrients, mostly N, P and K.
Manufacture of N-based synthetic fertilizers
requires fossil fuels as raw materials.
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Fertilizer Use:
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Nitrogen cycle
Source: http://www.allrefer.com/pictures/s4/p0001901-nitrogen-cycle
Fertilizer Use:
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Nitrogen cycle
Nitrogen
fertilizer
producing
factory
Fertilizer Use:
Teragrams of
nitrogen per
year
Projected human
input
Total human input
Fertilizers and industrial
uses
Nitrogen fixations in
agroecosystems
Fossil fuels
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07 Jan 2012
Fertilizer Use:
Nitrogen-based fertilizers can be washed
from the fields into rivers and streams.
Excessive amount of nitrogen in the water
could cause algal blooms that leads to
eutrophication and other harms.
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07 Jan 2012
Fertilizer Use:
Fertilizer run-off
Eutrophication
1. Algae grow fast, using
up lots of dissolved
oxygen in water.
2. Algae block sunlight
3. Aquatic plants begin
to die
4. Dead matter feeds the
microbes
5. Microbes compete for
dissolved oxygen
6. Water looses
dissolved oxygen
7. Fish die
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07 Jan 2012
Source: http://www.bbc.co.uk/gcsebitesize
Fertilizer Use:
Algal bloom in real life
in
Taihu Lake,
China
in
Great Lakes,
USA
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07 Jan 2012
Fertilizer Use:
“Red tide” of the
dinoflagellate Noctiluca
stretched for more than
20 miles along the
southern California
coast.
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Algal bloom in real life
Fertilizer Use:
Algal bloom in real life
Phaeocystis boom lead
to foam formation that
accumulate on nearby
coastal areas in the
North Sea
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Fertilizer Use:
Use of fertilizers has positive effects on
the economic and the social components
of sustainable development?
It has negative effect on the
ecological component?
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Algal bloom in real life
Fertilizer Use:
Harmful algal blooms (HABs)
could produce toxins that
accumulates in shellfish that
consume algae.
Health of the public that
consume the shellfish is at risk.
Affected areas should be closed
and get closed (in the west).
No fishing. Fishermen are
affected. Economy is affected.
What abut the economic and the social
components of SD?
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07 Jan 2012
Source: http://www.whoi.edu/redtide/page.do?pid=9257#
Fertilizer Use:
Algal bloom in real life
Researchers are
investigating the use of
natural clays in Florida’s
Sarasota Bay as a
potential tool to mitigate
harmful algal blooms, or
“red tide”.
What abut the economic component of SD?
R. Shanthini
07 Jan 2012
Source: http://www.whoi.edu/redtide/page.do?pid=9257#
Fertilizer Use:
Ways to Minimize
Crop rotation (or sequencing) Fertilizer Impact
It is not growing the same crop at the same plot of land
throughout the year.
Soil fertility: Different crops have different soil
requirements and benefits. Changing crops from year to
year minimises deficiencies and allows the soil to replenish.
Soil structure: Alternating between deep-rooted and
fibrous-rooted crops improves soil structure.
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07 Jan 2012
Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp
Fertilizer Use:
Ways to Minimize
Crop rotation (or sequencing) Fertilizer Impact
Examples
Cabbage
Cauliflower
Soil requirements
nitrogen-rich soil;
may need liming
Soil benefits
Legumes
(Pea, bean)
well-drained;
moisture-retentive;
not nitrogen-rich
Fix atmospheric
nitrogen in roots for
future crops
Onion, Garlic
Leek
Potato
Tomato
Carrot
Celery
high organic matter;
may need liming
high organic matter and
nitrogen (potato); no lime
not freshly manured
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Suppress weeds, break
up soil structure
Root crops break up
soil structure
Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp
Fertilizer Use:
Biofertilizers
Ways to Minimize
Fertilizer Impact
An example:
Nitrogen fixing symbiotic systems such as Sesbania
rostrate Azolla and free-living cyanobacteria to rice crop
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07 Jan 2012
Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp
Pesticide Use:
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Fate of pesticides
in the environment
Source: http://www.ecifm.rdg.ac.uk/pesticides.htm
Pesticide Use:
Fate of pesticide in the environment is determined by its
characteristics, such as
• water solubility:
measures how easily a pesticide may be washed
off the crop, leach into the soil or move with
surface runoff.
• soil adsorption:
tendency of pesticides to be attached to soil
particles
• half-life:
pesticide persistence in the environment (or the
time in days required for a pesticide to degrade in
soil to one-half its original amount)
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http://www.agf.gov.bc.ca/pesticides/c_2.htm
Pesticide Use:
Water
Soil
Half-life
solubility adsorption
high
low
low
very high
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07 Jan 2012
Long
(more than
21 days)
Fate of pesticide
Move into water
Strongly attached
to soil
http://www.agf.gov.bc.ca/pesticides/c_2.htm
Pesticide Use:
The purpose of using pesticides / herbicides is to kill.
They could kill not only pests and weeds (which they are
supposed to) they could also kill and harm beneficial
organisms and plants.
DDT, a compound found in pesticides, had worked its
way up the food chain, bioaccumulating or increasing in
concentration at every level until it was enough to
weaken the shells of eagle eggs.
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07 Jan 2012
Pesticide Use:
Ways to Minimize
Pesticide Impact
Crop Rotation (or Crop Sequencing)
Pest and disease control: Soil pests and diseases tend
to attack specific plant families, so by rotating crops the
pests' life-cycles are broken and build-up is reduced.
Weed control: Some crops (e.g. potatoes) can suppress
weeds, minimising problems for following crops.
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07 Jan 2012
Pesticide Use:
Ways to Minimize
Pesticide Impact
Crop Rotation (or Crop Sequencing)
Farmers in Matale district rotate tomato with paddy.
The crop is planted in Yala (dry season) followed by
paddy in the Maha (wet season)
P. Solanacearum which causes bacterial wilt in tomato is
unable to live under anaerobic conditions. Hence six
months rotation is effective in controlling the disease.
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07 Jan 2012
Dr. C. Kudagamage
Deputy Director (Research)
Horticultural Crop Research &
Development Institute
Gannoruwa, Peradeniya
Pesticide Use:
Ways to Minimize
Pesticide Impact
Integrated Pest Management (IPM)
IPM doesn't rely solely on chemicals for pest control.
Biological control, cultural practices, and timely
chemical applications are used to obtain the
necessary level of control.
Pesticides are the last line of defence and are used
only when pest levels are causing sufficient damage
to offset the expense of the application.
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07 Jan 2012
http://www.agf.gov.bc.ca/pesticides/c_2.htm
Pesticide Use:
Ways to Minimize
Pesticide Impact
Native Plants Garden
Planned for NO use of herbicides / pesticides
Weeds removed by hand
Choose plants that grow quite densely, leaving little room
for weeds once they are established
Tolerate many insects as part of the garden's miniecosystems (caterpillars bring birds to the garden!)
R. Shanthini
07 Jan 2012
http://www.agf.gov.bc.ca/pesticides/c_2.htm