1. Ecosan Expert Training Course
Capacity Building for Ecological Sanitation
Agricultural Aspects
Katharina Conradin & Martin Wafler, seecon international

2. Requirements for Plant GrowthFe
Light Cu Ca P K O2
Water Mg
Soil Structure N S B
Source: Vinnerås (5)
Temperature
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) 2

3. 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
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)
“Elements essential for the growth of plants are called nutrients. The nutrients used in the largest amounts are the non-mineral elements, i.e. carbon, hydrogen and oxygen. These elements are mainly taken up as carbon dioxide (CO2) from the air, and water (H2O) by the roots. Increasing the supply of light, carbon dioxide, water and mineral nutrients from the deficiency range increases the growth rate and crop yield.
Nutrients can be divided into the two categories; macronutrients and micronutrients. The uptake of macronutrients is about 100 times that of micronutrients. The six elements normally classified as macronutrients are nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca) and magnesium (Mg). These nutrients are mainly taken up from the soil by the roots in ionic form.
Micronutrients are as essential for plant growth as macronutrients, but are taken up in small (micro) amounts. The elements normally considered micronutrients are boron, copper, iron, chloride, manganese, molybdenum and zinc (6,7).
Fertilization increases crop yield only if the plant nutrient supplied is one of the most limiting growth factors (see figure above). No yield increase is to be expected when fertilizing crops that are mainly limited by factors other than nutrient supply, e.g. lack of water, too low or too high pH, etc.”
For more information on nutrients in human excreta, refer to Module M2-2.
Source: (5)
Plant growth, green colour (photosynthesis), protein content
Root growth, regulates plant metabolism, seed and fruit development
Plant growth, regulates transpiration in plant
Source: (5) 3

4. Nutrient Export from Agricultural Land
In an agricultural ecosystem, minerals and organic matter are exported from the soil by harvesting the products. 4

5. What is artificial fertilizer?
Sulphur
Potassium
Phosphorus
Nitrogen

6. What is artificial fertilizer?
N P K
Balance = SALTS
Balance…?
= ...? 40

7. Soil Degradation: Salinization
“Though fertilizing is intended to enhance soil fertility, it can also lead to the adverse effects. Soil fertility requires nutrients to exist not only in sufficient quantities, but also in balanced form. Too much of one nutrient may lock up or interfere with the absorption of another. The ratio of nitrogen to phosphorus is important to proper plant nutrition because inadequate nitrogen supply slows the growth of roots and, therefore, their ability to reach phosphorus supplies. Micronutrient problems are often a result of imbalances and thus a reduced – not an increased fertility.
Eutrophication: An excess of certain soil nutrients, impairing plant growth, due to imbalanced application of organic and chemical fertilizer resulting in excess Nitrogen, Phosphorus, or liming. Additionally, excess nutrients are washed out from the soils into nearby waterbodies, thus leading to eutrophication there as well.
Often, loss of soil fertility is also caused by a lack of organic content, due to the fact that only (or mainly) chemical fertilizers are applied. However, if organic compounds are neglected, a negative balance between output (through harvesting, burning, leaching, etc.) and input (through manure/fertilizers, returned crop residues, flooding) of nutrients and organic matter results. This leads to a net decrease of available nutrients and organic matter in the soil.”
Source: (13)
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

8. Soil Degradation Very high severity High severity Moderate severity
Low severity
Stable Land, Ice Caps or non-used wasteland
Source:
Human induced soil degradation has reached critical states in many regions of the world – hotspots are not only to be found in the so called developing world, but also in large parts of the united states and eastern Europe. However, soil degradation is especially severe in areas that already today have a very high population density, such as India and large parts of China – but as well the Sahel belt in Sub-Saharan Africa shows critical values.
Global status of human-induced soil degradation.

9. 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

10. 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) 10

11. Nutrient excretion by humans
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!

12. Nutrients in “Wastewater”
Greywater
Faeces
Urine
Most of the nutrients that are essential in agriculture (N, P, K) occur in urine. Faeces contain smaller amounts of these substances, while the quantities in greywater are insignificant. Separating urine, which only accounts for about 1% of the total wastewater flow, and using it as fertilizer makes it possible to utilize most of the nutrient content of wastewater. If faecal material is separated too, only small amounts of nutrients remain in the greywater. It must be borne in mind that greywater represents by far the greatest volume of wastewater and must still be treated. Consequently, urine separation cannot replace other treatment methods but is a complement that helps to recycle a larger proportion of the nutrients in wastewater (1).
Source: (1)
Nitrogen
Phosphorus
Potassium
Wastewater Flow

13. Human Excreta - A Valuable Resource
million tons per year
(as N + P2O5 + K2O)
135 50
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

14. Quantification and Characterization of Human Urine
Averaged values from various studies conducted in North America and Europe
source (2)

15. Quantification and Characterization of Human Feces
Averaged values from various studies conducted in North America and Europe
source (2)

16. 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
Source: Yadav, 2008

17. Estimated Excretion of Nutrients per capita in Different Countries
source (7) in (6)

18. Nutrients and Fertilizer Requirements
Source: (33)
As the above table shows, 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. Concerning Phosphorus and Potassium, the nutrient requirements could almost be fully met, just by reusing resources contained in what is commonly called wastewater – but what actually should not be considered waste at all.
Source: (33)
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.

19. Plant Availability of Nutrients in Urine and Faeces
mostly water-soluble  directly available to plants,
rapid plant availability
Jef Vivant
Let`s separate!
“While the nutrients in urine are mostly water-soluble and thus directly available to plants, faeces contain both water-soluble and nutrients that are combined in larger particles not soluble in water. The plant availability of the nutrients in the faecal matter is lower and slower than that of the urine nutrients. This is due to the fact that the main proportion of the P and a large proportion of the N stem from undigested matter and this matter needs to be degraded in the soil to become available to plants. However the organic material in the faeces degrades and its content of organic N and P then becomes available to plants.
The organic matter contributes in several ways: by improving the soil structure, increasing the water- holding capacity and the buffering capacity, and by supporting the soil microorganisms by serving as an energy source.”
Source: (5)
Nutrients in Faeces:
both water-soluble + non water-soluble nutrients
slower plant availability (need degradation)
Organic material: water holding capacity
with compost
Without compost
Seedlings after one week without water 19

20. Benefits of Organic Matter
Source: T. Alföldi (22)
With 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
“While the nutrients in urine are mostly water-soluble and thus directly available to plants, faeces contain both water-soluble and nutrients that are combined in larger particles not soluble in water. The plant availability of the nutrients in the faecal matter is lower and slower than that of the urine nutrients. This is due to the fact that the main proportion of the P and a large proportion of the N stem from undigested matter and this matter needs to be degraded in the soil to become available to plants. However the organic material in the faeces degrades and its content of organic N and P then becomes available to plants.
The organic matter contributes in several ways: by improving the soil structure, increasing the water- holding capacity and the buffering capacity, and by supporting the soil microorganisms by serving as an energy source.”
Source: (5)
Pic: soil surface in winter wheat plots. Earthworm casts and weed seedlings are more frequent in the biodynamic plot (top 26). Disaggregation of soil particles in the conventional plots (bottom 75) leads to a smoother soil surface. Wheat row distance is m.
Seedlings after one week without water
with compost
Without compost
With artificial fertilizer 20
Source: (5)

21. Visible Effects of Urine as Fertilizer
Alfalfa (animal fodder)
These pictures show results from the trial garden in Khatgal. The amounts of fertilizer increase from left to right – and the results are visible!
Barley
…it works!
Oats

22. Visible Effects of Urine as Fertilizer
No Urine
Urine
No Urine
Urine

23. 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

24. 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
Greywater (sanitised)
Water for plant growth (irrigation),
Fertiliser:
Nutrients available in small contents

25. Ecosan Expert Training Course
Capacity Building for Ecological Sanitation in Bhutan
Agricultural Aspects
Katharina Conradin & Martin Wafler, seecon international