Transcript Document

Course 3 Unit 1
Extra Material
Overview on hunger, food and fertiliser
Teacher
Mariska Ronteltap
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[email protected]
Let's look at this anecdote:
“In Uganda, banana trees are growing very well on old
abandoned wastewater treatment ponds (as well as
on filled pit latrines). The plants take nutrients from
the excreta-based sludge in the ponds. People
harvest these bananas at night secretly and sell them
on the local market. The bananas are tasty and
healthy but if consumers knew their origin, they
wouldn’t buy them.”
Story told by Ugandan MSc participants during ecosan summer school at UNESCOIHE, Sept. 2007
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Overview: benefits of using sanitised urine, faeces,
greywater in agriculture
(further details provided in Course 3 Unit 2)
Ecosan product
Main benefit
Further benefits
Urine (sanitised)
Fertiliser: nitrogen content
Fertiliser: phosphorus
content
Faeces (sanitised)
Soil conditioner: organic
matter content (especially
useful if converted to
compost); improves soil
structure
Fertiliser: phosphorus
content
Greywater (sanitised)
Water for plant growth
(irrigation)
-
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Is this reuse of excreta in agriculture a
new idea?
Definitely not! You don’t have to look far and you find many
examples where people are doing it or where doing it in the past
 In Europe, “night soil” collection from the cities was common  use
of excreta in agriculture. This came to an end when the production
of artificial mineral fertilisers to boost crop yields was mastered
(around 1850s).
• We used to have “sewage farms” in Europe – spreading sewage onto
land (see next slide)
 Banana trees growing in abandoned (filled) pits of pit latrines is
very common in African countries
So it’s not a new practice at all. Some of the older practices were
not done safely though. In ecosan we do our best to practise this
reuse in a safe manner.
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Course 3 Unit 1
A “sewage
farm” in the
USA around
1900
Distribution of sewage from gravity outfall sewer via open trenches and irrigation ditches at "sewer farm".
Sewage was conveyed from downtown Salt Lake City to sewer farms several miles northwest of the city for
reuse and disposal. Sewage was distributed to crop areas by open conveyance systems. Source: Utah
State Historical Society, Photo no. C-601 #1604. - Around year 1900.
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http://sewerhistory.org/grfx/trtmnt/trtmnt1.htm
Multiple links between ecosan and improved health of
people (particularly children)
Source: Esrey et al. (2001), p. 58
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Reminder (from Course 1 Unit 1): Half of all deaths of young
children are associated with malnutrition
ARI = Common cold; a
viral infectious disease
of the upper respiratory
system
Neonatal: in first
27 days of life
Source: http://childinfo.org/areas/childmortality
Data for 2000-2003
An ecosan approach could have a direct impact on reduced diarrhoeal diseases (by improved
sanitation) and reduced malnutrition (by use of ecosan products as fertiliser)
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Hunger Map (in 2003)
Course 3 Unit 1
Orange, red and dark red
areas: > 25% of the
population is
undernourished!
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Source: http://faostat.fao.org/site/563/default.aspx
Future developments regarding hunger
Hunger problem may well become even worse again, due to rising
costs of many food items; some reasons for rising costs:
 Increased demand from rising world population
 Increased demand for meat and dairy products from countries
where populations are getting wealthier (China, India)
• Meat-based diet requires more land, energy, water and fertiliser than
vegetable-based diet! (should we all become vegetarians?)
 Less land available for food production if farmers switch to biofuels
production (e.g. US, Europe)
 Rising oil prices (transport of food and fertiliser)
 Increasing fertiliser prices (see Part B of this presentation)
 Deteriorating soil fertility, land degradation
 Possible climate change impacts, e.g. changing weather patterns,
droughts, floods
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Global risk factors for disease and premature deaths
(% of DALYs)
Child underweight for age
Unsafe water, sanitation, hygiene
Low fruit & vegetable intake
Zinc deficiency
Iron deficiency anaemia
Vitamin A deficiency
Source and further
explanations: see next slide
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Observations for previous slide (1/2)
(provided by Håkan Jönsson)
About half of the burden due to child underweight is in Sub-Sahara,
and the main other part is in South Asia (the situation is about
the same for Unsafe water & sanitation, zinc deficiency and
Vitamin A deficiency, while iron deficiency and low fruit and
vegitable intake are more evenly distributed).
The Disability Adjusted Life Year or DALY is a health gap measure
that extends the concept of potential years of life lost due to
premature death to include equivalent years of ‘healthy’ life lost
by virtue of being in states of poor health or disability (for more
information on DALY see Appendix of presentation for Course 3
Unit 2).
Full Reference: Lopez, A D , C D Mathers, M Ezzati, D T Jamison, C J L
Murray. (2006) Global and regional burden of disease and risk factors,
2001: systematic analysis of population health data. Lancet (North
American Edition) 367 (9524): 1747-1757.
FAO. 2006. The state of food insecurity in the world. Eradicating world
hunger – taking stock 10 years after the world food summit. FAO.
Rome, Italy. Download:
2006ftp://ftp.fao.org/docrep/fao/009/a0750e/a0750e00.pdf
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Course 3 Unit 1
Observations for previous slide (2/2)
“Of course can ecosan not solve all problems, just like good sanitation
can not solve all water and hygiene problems. This graph shows
more how much bigger our target group is than what it is if we just
do sanitation. And if we can make ecosan function, it can do quite a
bit.
Also observe that about half of the under nutrition, zinc and vitamin A
deficiencies are in Sub-Saharan Africa, where the use of fertilizers
is really low – the second slide (see next slide) shows that the plant
nutrient supply could be doubled if all urine and faeces is
recovered.
And it is the most poor that suffer from chronic hunger and one
resource that these always have it that they do own their excreta. It
is quite another thing however, if they have any land to put it on.
But I do think that many of the hungry people are rural ones (have
no data yet on this though) and for these more nutrients could be of
great value.”
E-mail on 25 Sept. 2007 from Håkan Jönsson, Stockholm
Environment Institute
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Potential recycled nutrients as % of currently utilised
chemical fertilizer nutrients
Excreta nutrients as % of nutrients in used fertilisers 2002
120,0%
100,0%
80,0%
60,0%
40,0%
20,0%
0,0%
Developed
Regions
East Asia
Ref: Rockström et al., 2005 (p. 56)
Eurasia
Latin
North Africa
America
and the
Carribbean
Nitrogen
Oceania
South-east
Asia
Southern
Asia
Subsaharan
Africa
West Asia
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Phosphorus
Source: FAOstat (2005
Fertiliser use in sub-Saharan Africa is not increasing much unlike in
other development regions
(source: see notes on next slide)
Düngemittelverbrauch
in kg (N,
Nährstoff
P 2 O5 ,
use in kg nutrient
Fertiliser
(N, P2O5, K2O) pro ha
K2O) per ha
120
100
Sub-Saharan
Africader Sahara
Afrika südlich
South Süd-Asien
Asia
Süd-Amerika
South America
Entwicklungsländer
All developing
countries
80
60
40
20
0
1960
1970
1980
1990
2000
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Source of data for previous slide
The graphic was taken from a presentation by Germer,
Grenz, Sauerborn (2007) – see https://www.unihohenheim.de/respta/info.php
The raw data on fertiliser use for all countries is
available here:
http://www.fao.org/statistics/yearbook/vol_1_1/pdf/a0
7.pdf
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Million tons per year
Global estimates: Mineral fertiliser consumption
compared to fertiliser value of wastewater
150
125
100
75
50
25
Source:
www.fertilizer.org
0
global mineral
fertilizer
consumption
global fertilizer
equivalent in
wastewater
 Yearly use: 135 Mio tons of mineral fertiliser
 Conventional sanitation dumps 50 Mio tons of fertiliser equivalents
- worth 15 Billion US dollar.” (Source: (1), shown on slide after next) (=1611
billion Euro with exchange rate of April 2007)
Course 3 Unit 1
Nutrients and Fertilizer Requirements
Fertilizer Equivalence of Yearly per Capita Excreted
Nutrients and Fertiliser Requirements for Producing
250 kg of Cereals
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Nutrient (kg)
5
cereal
requirements
4
faeces
3
2
urine
1
0
Source: (2)
N
N
P
P
K
K
A high percentage of the nutrient requirements for producing food crops (as an
example: 250 kg of cereals) could be met by recovering the nutrients contained in
urine and faeces.
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Source: (2), shown on next slide
Course 3 Unit 1
References for last two slides
Werner, C. (2004): Ecological sanitation – principles, urban
application and challenges. PP-Presentation. UN
Commission on Sustainable Development, 12th Session New York, 14-30 April
(2) Werner, C., Mang H. P., Klingel, F. Bracken, P.: General
Overview about ecosan. PowerPoint-Presentation.
Deutsche Gesellschaft für Technische Zusammenarbeit
(GTZ) GmbH ecological sanitation programme, Division 44
– environment and infrastructure
(1)
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Fertiliser value of excreta (rules of
thumb) – 1/2
If we take the N, P and K content of human excreta and
assume it could sell for the same value as you get for
N, P and K in inorganic chemical fertiliser, you can
come up with rough figures on the fertiliser value of
human excreta
The following rule of thumb for the fertiliser value of
excreta of one person (rule of thumb) were given by
Thor-Axel Stenström at the ecosan seminar in Sofia,
Bulgaria (April 2007):
 Norwegian person: € 3.7 per year
 Chinese person: € 2.0 per year
• Presumably because of lower calorific intake, and could also be
that artificial fertiliser is cheaper in China than in Norway
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Fertiliser value of excreta (rules of
thumb) – 2/2
If we take the Chinese figures (from previous slide) for
the whole world population of currently 6.5 billion, the
total fertiliser value of all human excreta* would be €
13 billion (compare with value on earlier slide of € 11
billion).
Such a figure can be useful to give an overview but of
course the reality is somewhat different:
 Cost of fertiliser also depends on availability, transport
distance, the form that is in (urine is relatively diluted) and
just general market forces
 So just treat the € 13 billion as a rough estimate
* Remember: excreted nutrients for a Chinese person in kg per person per year
estimated as 4/0.6/1.8 for N/P/K – see Course 1 Unit 2 Part A
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Example calculation: ”Fertiliser can pay
for toilet” (for India)
UDD toilet costs in India 4200 INR
Excretion of nutrients/person, year
N 4.55 kg, P 0.58 kg, K 1.27 kg
6 person family = 4 adults
N 18.2 kg/yr, P 2.3 kg/yr, K 5.1 kg/yr
NPK 25-2-6 (%) costs 10 INR/kg,
NPK 10-5-20 (= 10-2.2-16.6%) costs 5.5 INR/kg
Excreta worth 750 - 880 INR/year
Present value years 2-10=4300 - 5070 INR/kg
Ref: Jönssson, et al. 2005. Ecosan both Economical and Eco-sane. Water 21
(IWA International Water Associations monthly magazine) June issue p. 15.
(slide provided by Håkan Jönsson)
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