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

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(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

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: 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

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: (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