Overview on hunger, food and fertiliser Course 3 Unit 1Extra Material

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Teacher

Mariska Ronteltapm.ronteltap@unesco-ihe.org

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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 UNESCO-IHE, 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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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.http://sewerhistory.org/grfx/trtmnt/trtmnt1.htm

A “sewage farm” in the USA around

1900

Course 3 Unit 1

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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

Source: http://childinfo.org/areas/childmortalityData 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)

ARI = Common cold; a viral infectious disease of the upper respiratory system

Neonatal: in first 27 days of life

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Hunger Map (in 2003)

Source: http://faostat.fao.org/site/563/default.aspx

Course 3 Unit 1

Orange, red and dark red areas: > 25% of the population is undernourished!

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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)

Source and further explanations: see next slide

Child underweight for age

Unsafe water, sanitation, hygiene

Low fruit & vegetable intake

Zinc deficiency

Iron deficiency anaemia

Vitamin A deficiency

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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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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

Course 3 Unit 1

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Potential recycled nutrients as % of currently utilised chemical fertilizer nutrients

0,0%

20,0%

40,0%

60,0%

80,0%

100,0%

120,0%

DevelopedRegions

East Asia Eurasia LatinAmericaand the

Carribbean

North Africa Oceania South-eastAsia

SouthernAsia

Sub-saharanAfrica

West Asia

Exc

reta

nu

trie

nts

as

% o

f n

utr

ien

ts in

use

d f

ert

ilise

rs 2

00

2

Nitrogen PhosphorusSource: FAOstat (2005)

Ref: Rockström et al., 2005 (p. 56)

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Fertiliser use in sub-Saharan Africa is not increasing much unlike in other development regions (source: see notes on next slide)

1960 1970 1980 1990 2000

Dü

ng

em

itte

lve

rbra

uch

in k

g N

äh

rsto

ff

(N, P

2O

5, K

2O

) p

ro h

a

0

20

40

60

80

100

120Afrika südlich der SaharaSüd-AsienSüd-AmerikaEntwicklungsländer

Fer

tilis

er u

se in

kg

nutr

ient

(N

, P

2O5,

K

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Sub-Saharan AfricaSouth AsiaSouth AmericaAll developing countries

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Source of data for previous slideThe graphic was taken from a presentation by Germer,

Grenz, Sauerborn (2007) – see https://www.uni-hohenheim.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/a07.pdf

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Global estimates: Mineral fertiliser consumption compared to fertiliser value of wastewater

0

25

50

75

100

125

150

global mineralfertilizer

consumption

global fertilizerequivalent inwastewater

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) (= 11 billion Euro with exchange rate of April 2007)

Source: www.fertilizer.org

Mill

ion t

ons

per

year

Nutrients and Fertilizer Requirements

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.

Fertilizer Equivalence of Yearly per Capita Excreted Nutrients and Fertiliser Requirements for Producing

250 kg of Cereals

0

1

2

3

4

5

6

N N P P K K

Nu

trie

nt

(kg

)

cerealrequirements

faeces

urine

Source: (2)

Source: (2), shown on next slide

Course 3 Unit 1

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References for last two slides(1) 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

Course 3 Unit 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, yearN 4.55 kg, P 0.58 kg, K 1.27 kg

6 person family = 4 adultsN 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)