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Agricultural Aspects
Katharina Conradin & Martin Wafler, seecon international
Capacity Building for Ecological Sanitation
Ecosan Expert Training Course
Requirements for Plant Growth
N P K
Wate
r
Lig
ht
Tem
pera
ture
S
So
il stru
ctu
re
B Ca
O2
Mg
Fe
Cu
Yield
NN P K
Wate
r
Lig
ht
Tem
pera
ture
S
So
il stru
ctu
re
B Ca
O2
Mg
Fe
Cu
Yield
N
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.
Sou
rce:
Vin
nerå
s (5
)
Sou
rce:
(5)
Cu F
e
So
il S
tru
ctu
re
Tem
per
atu
re
Wat
er
Lig
ht
Ca
MgN P K S B O
2
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
Source: (5)
Micronutrients
Uptake in very small (micro) amounts
• Boron (Bh)
• Copper (Cu)
• Iron (Fe)
• Chloride (Cl)
• Manganese (Mn)
• Molybdenum (Mo)
• Zinc (Zn)
Macronutrients:
Uptake is about 100 times that of micronutrients:
• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Sulphur (S)
• Calcium (Ca)
• Magnesium (Mg)
Plant growth, green colour
(photosynthesis), protein content
Root growth, regulates plant metabolism,
seed and fruit development
Plant growth, regulates transpiration in plant
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?
Nitrogen Phosphorus
Potassium
Sulphur
http://www.uspanteco.org
What is artificial fertilizer?
N P K
16 8 16
16 + 8 + 16 = ...?40 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
Soil Degradation
Global status of human-induced soil degradation.
Sou
rce
: w
ww
.fa
o.o
rg
Very high severity
High severity
Moderate severity
Low severity
Stable Land, Ice Caps or non-used wasteland
Advantages / Disadvantages of Artificial Fertilizers
• Initial rise in yield• Easy to handle (usually
relatively small amounts required)
• Composition adapted to the needs of different crops
• 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
Advantages Disdvantages
Closing the loop between sanitation and agriculture
NUTRIENTS NUTRIENTS
closing the loopbetween sanitation
and agriculture
FOOD
Pathogen destruction
Source: (4)
The basic principle of ecosan is to close the loop between sanitation and agriculture without
compromising health
ENERGY
GARDENS
FOOD
ENERGY
GARDENS
Nutrient excretion by humans
We excrete the same amount of nutrients that we take up in our diet (except for children growth of bones)
N
N
P
P
DIET
EXCRETA
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”
Sou
rce
: (1
)
Nitrogen Phosphorus Potassium Wastewater Flow
Greywater Faeces Urine
Human Excreta - A Valuable Resource
0
25
50
75
100
125
150
global mineralfertilizer
consumption
global fertilizerequivalent inwastewater
million tons per year
(as N + P2O5 + K2O)135
50
ww
w.f
ertil
izer
.org
more than 1/3 of global mineral fertilizer consumption can be covered by the reuse of human excretaover 15 billion US$ fertilizer equivalent are annually flushed down the toilet
Quantification and Characterization of Human Urine
parameter unit no of
samples min. max.
standard deviation
average median value
volume * l/ppd 16 0.5 2.0 0.26 1.2 1.2 1.2 weight * g/ppd 16 500 2,000 260 1,200 1,200 1,200
Total Solids g/ppd 7 20 147 32.9 72.4 60.0 60 organic Total
Solids g/ppd 5 65 85 9.58 39.1 45 45
organic carbon
g/ppd 5 1.8 11.9 2.83 6.6 8.4 8.5
BOD5 g/ppd 2 1.8 13.6 2.17 7.5 7.5 7.5 COD g/ppd 2 5.4 30 4.74 15.1 15.1 15 Total
Nitrogen g/ppd 14 3.6 16 2.45 10.4 10.9 11
Total Phosphorus
g/ppd 14 0.5 2.5 0.41 1.1 1.0 1
Potassium g/ppd 11 1.0 4.9 0.59 2.3 2.5 2.5 Calcium g/ppd 6 0.15 2.2 1.06 1.3 1.4 1.4
Magnesium g/ppd 4 0.06 0.2 0.14 0.2 0.1 0.1 carbon to nitrogen
- 6 0.4 1.2 0.27 0.8 0.8 0.8
* density = 1.0 kg/dm3 ppd = per person per day g = grams l = liters
Averaged values from various studies conducted in North America and Europe
source (2)
Quantification and Characterization of Human Feces
parameter unit no of
samples min. max.
standard deviation
average median value
volume * l/ppd 9 0.07 0.4 0.05 0.18 0.15 0.15 weight * g/ppd 9 200 400 50 180 150 150
Total Solids g/ppd 6 30 60 8.6 44.7 45.0 45 organic Total
Solids g/ppd 4 26 58 6.2 44.8 42.0 42
organic carbon g/ppd 6 13.2 33 4.1 21.4 21.8 22 BOD5 g/ppd 1 6 18 - 11.1 11.1 11 COD g/ppd 1 19 55 - 33.0 33.0 33
Total Nitrogen g/ppd 11 0.25 4.2 0.9 2.0 1.9 2 Total
Phosphorus g/ppd 11 0.1 1.7 0.33 0.7 0.6 0.6
Potassium g/ppd 7 0.2 1.3 0.21 0.7 0.6 0.6 Calcium g/ppd 2 0.67 1.4 0.52 1.1 1.1 1.1
Magnesium g/ppd 1 0.12 0.18 - 0.15 0.15 0.15 carbon to nitrogen
- 5 5 11.3 1.79 8.2 7.5 7.5
* density = 1.0 kg/dm3 ppd = per person per day g = grams l = liters
source (2)
Averaged values from various studies conducted in North America and Europe
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
Human Feces Composition (Indian Condition)
Source: Yadav, 2008
Estimated Excretion of Nutrients per capita in Different Countries
source (7) in (6)
Nutrients and Fertilizer Requirements
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.
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: (33)
Plant Availability of Nutrients in Urine and Faeces
Nutrients in Urine:
mostly water-soluble directly available to plants,
rapid plant availability
Nutrients in Faeces:
both water-soluble + non water-soluble nutrients
slower plant availability (need degradation)
Organic material: water holding capacity
Jef Vivant
Let`s separate!
Seedlings after one week without water
with compost
Without compost
Benefits of Organic Matter
Benefits of Organic Matter:
Improves soil structure
Improves pore space
Increases water-holding
Better water supply for crops
Diversity of micro-organisms
Multitude of biochemical processes
Capacity to buffer pH and pollutants
Better storage and exchange capacity for (micro) nutrients
Reservoir of N P K S steadily released by mineralisation
Source: (5)
Source: T. Alföldi (22)
With organic matter
With artificial fertilizer
Seedlings after one week without water
with compost
Without compost
Alfalfa (animal fodder) Barley
Oats
…it works!
Visible Effects of Urine as Fertilizer
Visible Effects of Urine as Fertilizer No Urine Urine
No Urine Urine
Advantages / Disadvantages of Compost & Urine as Fertilizer
• 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)
Advantages Disdvantages
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
Agricultural Aspects
Capacity Building for Ecological Sanitation in Bhutan
Ecosan Expert Training Course
Katharina Conradin & Martin Wafler, seecon international