Ecosan Expert Training Course
Capacity Building for Ecological Sanitation
Agricultural Aspects
Katharina Conradin & Martin Wafler, seecon international
Requirements for Plant Growth
Requirements for plant growth:
• light,
• water
• structure for roots
• nutrients.
 When supply of most limiting growth factor is increased, then other growth
factors become important as limiting factors.
 If factors other than nutrients are limiting, increasing nutrients will not help.
Source: (5)
Mg
K
K
S B
S
B
O2 Ca
MgO2
P
N P
N
N
Ca
Water
Light
Cu
Fe
Fe
Soil structure
Soil Structure
Temperature
Temperature
Water
Light
Cu
Source: Vinnerås (5)
Yield
Macronutrients & Micronutrients
Nutrients: essential elements
• Largest uptake: carbon, hydrogen and oxygen (in the form of
CO2 and water (H20)
• Increase in: light, carbon dioxide, water and mineral nutrients 
increased growth
Macronutrients:
Uptake is about 100 times
that of micronutrients:
• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Sulphur (S)
• Calcium (Ca)
• Magnesium (Mg)
Source: (5)
Plant growth, green
colour
(photosynthesis),
protein content
Root growth, regulates
plant metabolism,
seed and fruit
development
Plant growth, regulates
transpiration in plant
Micronutrients
Uptake in very small (micro)
amounts
• Boron (Bh)
• Copper (Cu)
• Iron (Fe)
• Chloride (Cl)
• Manganese (Mn)
• Molybdenum (Mo)
• Zinc (Zn)
Nutrient Export from Agricultural Land
In an agricultural ecosystem, minerals and organic matter
are exported from the soil by harvesting the products.
What is artificial fertilizer?
Sulphur
Potassium
Nitrogen
Phosphorus
http://www.uspanteco.org
What is artificial fertilizer?
N
16
16 + 8 + 16 = ...?
40
P
8
K
16
Balance…?
Balance = SALTS
Soil Degradation: Salinization
Salinisation in
Gujarat
Build-up
of salts
Die off of
natural bacteria
/
microorganisms
in the soil
Nutrient holding /
transforming
capacity of soil
decreases
Yield
goes
down
Source: www.fao.org
Soil Degradation
Very high severity
High severity
Moderate severity
Low severity
Stable Land, Ice Caps or
non-used wasteland
Global status of human-induced soil degradation.
Advantages / Disadvantages of Artificial Fertilizers
Advantages
• Initial rise in yield
• Easy to handle (usually
relatively small amounts
required)
• Composition adapted to the
needs of different crops
Disdvantages
•
•
•
•
•
Costly
Build-up of salts
Not balanced
Not complete
Can destroy crumb structure
of the soil (no organic
material added)
• Negative effects on
microorganisms in soil
•  reults possibly in land
degradation
• Are easily washed out of the
soil
Closing the loop between sanitation and agriculture
The basic principle of ecosan is to close the loop
between sanitation and agriculture without
compromising health
GARDENS
GARDENS
ENERGY
ENERGY
FOOD
FOOD
closing the loop
between sanitation
and agriculture
NUTRIENTS
NUTRIENTS
Pathogen
destruction
Source: (4)
Nutrient excretion by humans
N
N
DIET
EXCRETA
P
P
We excrete the same amount of nutrients that we take
up in our diet (except for children  growth of bones)
The amount of excreted nutrients by one person is the
same amount that is needed as fertiliser to grow the food for
that person
 Such a beautiful well-balanced loop!
Nutrients in “Wastewater”
Nitrogen
Faeces
Phosphorus
Potassium
Urine
Source: (1)
Greywater
Wastewater Flow
Human Excreta - A Valuable Resource
(as N + P2O5 + K2O)
150
125
135
100
75
50
50
25
www.fertilizer.org
million tons
per year
0
global mineral
fertilizer
consumption
global fertilizer
equivalent in
wastewater
more than 1/3 of global mineral fertilizer consumption can be covered by the reuse of
human excreta
over 15 billion US$ fertilizer equivalent are annually flushed down the toilet
Quantification and Characterization of Human Urine
Averaged values from various studies conducted in North America and Europe
parameter
unit
volume *
l/ppd
weight *
g/ppd
Total Soli ds
g/ppd
organic Total
g/ppd
Soli ds
organic
g/ppd
carbon
BOD5
g/ppd
COD
g/ppd
Total
g/ppd
Nitrogen
Total
g/ppd
Phosphorus
Potassium
g/ppd
Calcium
g/ppd
Magnesium
g/ppd
carbon to
-
nitrogen
* density = 1.0 kg/dm3
no of
samples
16
16
7
min.
max.
0.5
500
20
2.0
2,000
147
standard
deviation
0.26
260
32.9
5
65
85
5
1.8
2
2
average
median
value
1.2
1,200
72.4
1.2
1,200
60.0
1.2
1,200
60
9.58
39.1
45
45
11.9
2.83
6.6
8.4
8.5
1.8
5.4
13.6
30
2.17
4.74
7.5
15.1
7.5
15.1
7.5
15
14
3.6
16
2.45
10.4
10.9
11
14
0.5
2.5
0.41
1.1
1.0
1
11
6
4
1.0
0.15
0.06
4.9
2.2
0.2
0.59
1.06
0.14
2.3
1.3
0.2
2.5
1.4
0.1
2.5
1.4
0.1
6
0.4
1.2
0.27
0.8
0.8
0.8
ppd = per person per day
g = gra ms
l = li ters
source (2)
Quantification and Characterization of Human Feces
Averaged values from various studies conducted in North America and Europe
parameter
unit
volume *
l/ppd
weight *
g/ppd 
Total Soli ds
g/ppd 
organic Total
g/ppd 
Soli ds
organic carbon g/ppd 
BOD5
g/ppd 
COD
g/ppd 
Total Nitrogen g/ppd 
Total
g/ppd 
Phosphorus
Potassium
g/ppd 
Calcium
g/ppd 
Magnesium
g/ppd 
carbon to
-
nitrogen
* density = 1.0 kg/dm3
no of
samples
9
9
6
min.
max.
0.07
200
30
0.4
400
60
standard
deviation
0.05
50
8.6
4
26
58
6
1
1
11
13.2
6
19
0.25
11
average
median
value
0.18
180
44.7
0.15
150
45.0
0.15
150
45
6.2
44.8
42.0
42
33
18
55
4.2
4.1
0.9
21.4
11.1
33.0
2.0
21.8
11.1
33.0
1.9
22
11
33
2
0.1
1.7
0.33
0.7
0.6
0.6
7
2
1
0.2
0.67
0.12
1.3
1.4
0.18
0.21
0.52
-
0.7
1.1
0.15
0.6
1.1
0.15
0.6
1.1
0.15
5
5
11.3
1.79
8.2
7.5
7.5
ppd = per person per day
g = gra ms
l = li ters
source (2)
Human Feces Composition (Indian Condition)
Wet Weight, g/capita/d
350±150
Dry Weight, g/capita/d
70±30
Moisture content, %
80±5
pH
5.3±0.2
Organic matter, % dry weight
82±5
Total Carbon-C, % dry weight
42.5±2.5
C:N ratio
12±1
Nitrogen-N, % dry weight
4.1±0.4
Phosphorous-P2O5, % dry weight
1.1±0.2
Potassium-K2O, % dry weight
2.8±0.17
Calcium-CaO, % dry weight
4.5±0.80
Magnesium-Mg, mg/g dry weight
8.2±1.5
Sodium-Na, mg/g dry weight
8.5±1.3
Iron-Fe, mg/g dry weight
3.8±0.9
Zinc-Zn, mg/g dry weight
0.24±0.04
Copper-Cu, mg/g dry weight
0.004±0.005
Manganese-Mn, mg/g dry weight
0.27±0.05
Total Coliform, MPN/g
108 -109
Source: Yadav, 2008
Estimated Excretion of Nutrients per capita in Different
Countries
source (7) in (6)
Nutrients and Fertilizer Requirements
Fertilizer Equivalence of Yearly per Capita Excreted
Nutrients and Fertiliser Requirements for Producing
250 kg of Cereals
6
Nutrient (kg)
5
cereal
requirements
4
faeces
3
2
urine
1
0
Source: (33)
N
N
P
P
K
K
A high percentage of the nutrient requirements for producing (as an example: 250 kg
of cereals) could be met by recovering the nutrients contained in urine and faeces.
Plant Availability of Nutrients in Urine and Faeces
Nutrients in Urine:
 mostly water-soluble
available to plants,

directly
Let`s
separate!
 rapid plant availability
Jef Vivant
Nutrients in Faeces:
 both water-soluble + non watersoluble nutrients
 slower plant availability (need
degradation)
with compost
Without
compost
 Organic material: water holding
capacity
Seedlings after one week without water
Benefits of Organic Matter
With organic matter
Benefits of Organic Matter:
Improves soil structure
Improves pore space
Increases water-holding
Better water supply for crops
With artificial fertilizer
Diversity of micro-organisms
with compost
Multitude of biochemical
processes
Without
Capacity to buffer
pH and
compost
pollutants
Better storage and exchange
capacity for (micro) nutrients
Reservoir of N P K S steadily
released by mineralisation
Source: T. Alföldi (22)
Seedlings after one week without water
Source: (5)
Visible Effects of Urine as Fertilizer
Alfalfa (animal fodder)
Barley
…it
works!
Oats
Visible Effects of Urine as Fertilizer
No Urine
Urine
No Urine
Urine
Advantages / Disadvantages of Compost & Urine as Fertilizer
Advantages
Disdvantages
• Balanced fertilizer
• Complete fertilizer: contains
all nutrients we excrete
• Good for soil structure
• Improves water holding
capacity
• Contains organic material
• Available free of cost
• No build-up of salts
• Fosters a rich live of soil
microorganism
• Closes the loop
• Concentration of nutrients
cannot be predicted entirely
• Not so concentrated
• Quality depends on quality of
raw product
• Can also be washed out of
the soil (esp. dissolved
nutrients in urine)
In any case: adequate
amount is crurical
Benefits of using sanitised urine, faeces & greywater
Ecosan product
Main benefit
Further benefits
Urine
(sanitised)
Fertiliser: nitrogen
content
Fertiliser:
phosphorus
content
Faeces
(sanitised)
Soil conditioner:
organic matter
content 
improves soil
structure
Fertiliser:
phosphorus
content
Greywater
(sanitised)
Water for plant
growth (irrigation),
Fertiliser:
Nutrients
available in
small contents
Ecosan Expert Training Course
Capacity Building for Ecological Sanitation in Bhutan
Agricultural Aspects
Katharina Conradin & Martin Wafler, seecon international