pesticides and the green revolution can we feed the planet?
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Pesticides and the GREEN REVOLUTION can we feed the planet?. Since 1950 food grew faster than population: population growth:1.7% per year food growth: 3% per year. 0% per year. land growth:. 10% of Earth’s surface produces food 37% of Earth’s land produces food - PowerPoint PPT PresentationTRANSCRIPT
Pesticides and theGREEN REVOLUTION
can we feed the planet?
Since 1950 food grew faster than population:
population growth: 1.7% per year
food growth: 3% per year
land growth: 0% per year
10% of Earth’s surface produces food37% of Earth’s land produces food
Total surface area of earth 5.1 1014 m2
Land 25% 1.3 1014 m2 13 Bha 10% 4.8 Bha
(1 hm = 102 m; 1 ha = 1 hm2 = 104 m2)
pastures: 3.3 Bhacropland: 1.5 Bha
A ra b lelan d11 %
(1 .4 4 b ill io nhec ta re s)
O the r la nd33 %
(4 .3 5 b illio nh ec ta res)
a
F o rest a nd w oo d land3 0 %
(3 .8 9 b illio nhe c ta res)
P e rm an en tm eado w s & p astu res
26 %(3 .3 6 b ill io n
hec ta re s)
17 % of a ra b le lan dis irriga te d(2 40 m illio n h ec tare s )
The Earth's LandTotal Area: 13 Billion Hectares
a"Other land" includes barren and developed land.
Source: Food and Agriculture Organization
from Committee for the National Institute for theEnvironment
http://www.cnie.org/pop/conserving/landuse2.htm
[1] development of high yield strains of grains
[2] increased use of inorganic fertilizers
[3] irrigation[4] synthetic pesticide use
The green revolution:
increase productioneliminate competition
3 times more foodbeing produced
then in 1950
Are thereany
environmental impacts?
Metabolic breakdown product, DDE:
Properties of DDT and other organic compounds
1. very stable
2. low stability in water
3. high stability in hydrocarbonsolvents
4. high toxicity to tissues
5. relatively low toxicity to humans
The idea ofBIOMAGNIFICATION
Fish are living separatory funnels
They ingest water containing DDT
The DDT dissolves in the fatty tissues of their bodies
Biomagnificationin Long Island Sound
[DDT] in sea water 0.000003 ppm
[DDT] in plankton 0.04 ppm
[DDT] in minnows 0.5 ppm
[DDT] in needle fish 2 ppm
[DDT] in cormorants 25 ppm
LD50A measure of toxicity
1. Feed DDT to rats (spike their food)
2. Continue upping their dose until half of the die
3. Measure concentration of DDT in the rats
4. LD50 = (mass of DDT in rats) # Kg of rat