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2. Requirements for Plant Growth
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
4. Fertilizer vs. Yield Yield plotted against fertilizer applicationYield plotted against fertilizer application
5. Nutrient Export from Agricultural Land
6. Problems in Agriculture: Soil Degradation Soil fertility defined through:
Sufficient quantities of nutrients
Balanced ratio of nutrients
Plant availability
Loss of soil fertility by a lack of organic matter
? decreased water holding capacity
soil structure Source: (13)
7. Problems in Agriculture: Soil Degradation Globally, 2 billion hectares have been degraded since 1945
23% of globally used land (17).
Most degradation in Asia, Africa and South and Central America
Not only marginal lands, but also formerly fertile soils (overexploitation)
Consequences:
loss of topsoil from water erosion
fertility decline (18).
8. Problems in Agriculture: Soil Degradation
9. Chemical Fertilizers: Phosphate Modern agriculture relies heavily on Inorganic Fertilizers and other Agrochemicals
P origins from Phosphate Rock
The process to extract phosphorus is particularly damaging (strip-mining). By-products include radioactive material and air pollution.
Very energy consuming
Phosphorus deposits often contaminated with arsenic or cadmium ? accumulation in soils
Phosphate is highly bondable ? high demand!
Limited resource
Recycling of phosphorus from conventional wastewater treatment plants very limited (contamination with heavy metals and micropollutants).
10. Chemical Fertilizers: Phosphate Reserves
11. Chemical Fertilizers: Nitrogen
78% of air is composed of Nitrogen
elemental form ? not plant available
transfer of N2 into ionic forms NH4+ and NO3- ? energy intensive!
energy supply through fossil fuels
emission of greenhouse gases
expensive
12. Chemical Fertilizers: Potassium Potassium mostly contained in small proportions in a large number of mineral formations,
? expensive and energy consuming to extract.
13. Closing the loop between sanitation and agriculture
14. Multiple Links Between ecosan, Agriculture and Health
15. Municipal Wastewater Used for Forestry In India
17. Plant Availability of Nutrients in Urine and Faeces Nutrients in Urine:
mostly water-soluble ? directly available to plants,
rapid plant availability Source: (5)
Source: (5)
18. Benefits of Organic Matter
19. Urea Facts Of the nitrogen in fresh urine, 75-90% is in the form of urea; remainder is in the form of ammonium or creatinine
Urea is (NH2)2CO an organic nitrogen compound (contributing to CODa content of urine)
Urea is easily converted to ammonium by urease in the urine piping system or in the sewer
In conventional mixed wastewater, about 78% of the total nitrogen is therefore in the form of ammonia already
Urea can be made artificially from ammonia and CO2 and is a popular fertiliser world-wide
Urea has the highest proportion of N of all liquid fertilisers: 46.4% N in urea
20. Main Processes During Urine Storage The nitrogen in fresh urine is mostly in the form of urea (75-90%), with very little ammonia
Upon storage, the urea is quickly degraded to ammonia (NH3) by the enzyme urease, and hence the ammonia concentration increases
Higher ammonia concentrations result in a pH increase to pH 9 - 9.3
The increased pH value causes a precipitation of certain crystals and precipitates (precipitation of P, Mg, Ca and NH4 occurs)
21. Information Urine Storage There is a risk of losing N in the form of ammonia with the ventilated air
The colour of the urine changes from bright yellow to orange/red
22. Storage Recommendations (Family level)
23. Storage Recommendations (Large Scale) Storage sealed tank or container:
prevents contact (humans or animals)
hinders evaporation of ammonia
The urine should preferably not be diluted:
harsher environment for microorganisms
prevents fly breeding
24. Concluding Recommendations: Urine Treatment Urine: low risk for transmission of disease ? Faecal contamination
Dilution should be avoided.
At household level the urine can be used directly.
Large-scale systems:
25. Urine as a Fertilizer: Dilution Urine can be applied neat (without dilution) or diluted with water.
Dilution level varies between approximately 1:1 to 10:1 and 3:1
26. Urine as a Fertilizer: Dilution Dilution
Urine can be applied neat (without dilution) or diluted with water. The dilution level varies between approximately 1:1 to 10:1, and 3:1 seems common.
Dilution increases:
the volume to be spread
labour
equipment needed,
the energy use
risk for soil compaction
Dilution decreases:
Risk of over-application
Risk of toxicity to plants
Urine must be applied at the rate corresponding to the desired application rate of N, while additional water should be applied according to the needs of the plants
Diluted urine should be handled in the same way as urine. In order to avoid smells, loss of ammonia, generation of aerosols, burns and possible contamination on plants by remaining pathogens, urine should be applied close to, or even better, be directly incorporated into the soil. Foliar (on leaves) fertilization is not recommended. (5)
Note: During storage, the urine should preferably not be diluted. Concentrated urine provides a harsher environment for microorganisms, increases the die-off rate of pathogens and prevents breeding of mosquitoes. Thus, the less water that dilutes the urine the better.
Dilution
Urine can be applied neat (without dilution) or diluted with water. The dilution level varies between approximately 1:1 to 10:1, and 3:1 seems common.
Dilution increases:
the volume to be spread
labour
equipment needed,
the energy use
risk for soil compaction
Dilution decreases:
Risk of over-application
Risk of toxicity to plants
Urine must be applied at the rate corresponding to the desired application rate of N, while additional water should be applied according to the needs of the plants
Diluted urine should be handled in the same way as urine. In order to avoid smells, loss of ammonia, generation of aerosols, burns and possible contamination on plants by remaining pathogens, urine should be applied close to, or even better, be directly incorporated into the soil. Foliar (on leaves) fertilization is not recommended. (5)
Note: During storage, the urine should preferably not be diluted. Concentrated urine provides a harsher environment for microorganisms, increases the die-off rate of pathogens and prevents breeding of mosquitoes. Thus, the less water that dilutes the urine the better.
27. Urine as a Fertilizer: Application Time and Frequency Early stages of cultivation: availability of all nutrients important
Applications:
In the early stages of cultivation, good availability of all nutrients is important to enhance growth. In large-scale crop production. If fertilizer is applied only once, this should normally be carried out prior to or at the time of sowing/planting. If the crop is fertilized twice, the second fertilization can be performed after approximately 1/4 of the time between sowing and harvest, differing depending on the needs of the crop.
The crop can also be continuously fertilized, e.g. if the urine is collected in smaller containers and used more or less directly. However, once the crop enters its reproductive stage it hardly takes up any more nutrients.
As a rule of thumb, fertilization should stop after between 2/3 and 3/4 of the time between sowing and harvest.
A waiting period of one month between fertilization and harvest is very advantageous from a hygiene point of view and recommended for all crops eaten raw (2).
In regions where there is heavy rainfall during the cropping season, repeated applications of urine may be an insurance against losing all the nutrients in one rainfall event.
The total applied amount of urine and whether it should preferably be applied once or several times also depends on the N need of the plant and its root size. Root size varies widely between different crops (Figure 3). Plants with inefficient or small root systems, e.g. carrots, onions and lettuce, can benefit from repeated applications of urine throughout the cultivation time (11).In the early stages of cultivation, good availability of all nutrients is important to enhance growth. In large-scale crop production. If fertilizer is applied only once, this should normally be carried out prior to or at the time of sowing/planting. If the crop is fertilized twice, the second fertilization can be performed after approximately 1/4 of the time between sowing and harvest, differing depending on the needs of the crop.
The crop can also be continuously fertilized, e.g. if the urine is collected in smaller containers and used more or less directly. However, once the crop enters its reproductive stage it hardly takes up any more nutrients.
As a rule of thumb, fertilization should stop after between 2/3 and 3/4 of the time between sowing and harvest.
A waiting period of one month between fertilization and harvest is very advantageous from a hygiene point of view and recommended for all crops eaten raw (2).
In regions where there is heavy rainfall during the cropping season, repeated applications of urine may be an insurance against losing all the nutrients in one rainfall event.
The total applied amount of urine and whether it should preferably be applied once or several times also depends on the N need of the plant and its root size. Root size varies widely between different crops (Figure 3). Plants with inefficient or small root systems, e.g. carrots, onions and lettuce, can benefit from repeated applications of urine throughout the cultivation time (11).
28. Urine as a Fertilizer: Application Time
29. Urine as a Fertilizer: Application Technique For best fertilizing:
Incorporate urine into soil ? avoids ammonia losses
shallow incorporation is enough
Methods: - small furrows
- Washing the nutrients into the soil with water, subsequent irrigation
30. Urine as a Fertilizer: Application Technique Drip irrigation possible
avoid blockages (salt precipitation)
Do not simultaneously expose all the roots of the plant to urine
Sensitive plants
Application prior to sowing/planting
Or application at a distance from the plant
Spreading with watering can: easy application for small-scale gardens
31. Practical Recommendations for Urine: Application Rate Urine is a quick-acting nitrogen-rich complete fertilizer
recommended application rate and time for chemical nitrogen fertilizers (urea or ammonium) best starting point for developing local recommendations for urine.
Application from prior to sowing, up until two-thirds of the period between sowing and harvest (depending on crop requirements)
In most cases: yield constant for the total application rate (applied in one large dose or in several smaller ones)
32. Treatment methods for faecal matter For safe reuse of faeces: Treatment is a must.
Prevent spreading of pathogens!
Treatment methods for faecal matter include:
Composting and digestion
Storage
Desiccation
Alkaline treatment
(Incineration)
33. Primary Treatment Storage: pathogen die off with time (no addition of new material!)
Tropical Conditions (28-30°C): 1 year of storage
Lower temperatures (17-20 °C) 1.5 years
Cold climates: up to 2 years
34. Air Drying of Faeces
35. Secondary Treatment Alkaline treatments: further addition of ash, lime or urea.
pH at least 9
Storage for at least 6 months -1 year
Composting:
Mainly suitable for large scale
Temp > 50°C should be obtained during at least one week in all material.
Storage at ambient conditions is less safe, but acceptable
Sun-drying or exposure to temperatures above 45°C will substantially reduce the time
37. Faeces as Fertilizer Organic matter:
increases the water-holding and buffering capacity of the soil for acids and nutrients
active and diverse microbial community in the soil
better soil structure (aeration, pores)
But: Higher hygienic risk ? hygienization crucial!
38. Faeces as Fertilizer Fertilizing Effects Depending on Treatment Faeces:
fertilizing effect varies much more than the effect of urine
fertilizing effect depending on treatment methods
Additives (ash,
sawdust, etc.) influence:
nutrient content
organic matter content
pH
39. Fertilizing Effects: Ash
40. Fertilizing Effects: Compost Compost:
Often some 40-70% of the organic matter can be lost
N is partially lost as well
Plant availability:
Nitrogen: organic form ? plant-available at the rate of degradation
organic matter
Phosphorus: bound in organic forms
Potassium: mainly in ionic form and thus plant-available
Additions of organic waste influence amount and characteristics of compost
41. Fertilizing Effects: Desiccation and Biogas Desiccation
fast drying with a low moisture level:
only small losses of both organic matter and N
recycles more organic matter compared to composting
but the organic matter is less stable
Residues from anaerobic digestion (Biogas Production)
40-70% of organic matter degraded
mineralized N is not lost
40-70% of the N found in the residue is in the form of ammonium ? readily plant-available.
well-balanced, quick-acting and complete fertilizer
mostly, animal manure and household waste are added ? affects characteristics
42. Practical Recommendations for Faeces: Application Time Application prior to sowing or planting
P very important for good development of seedlings and root system
incorporation into the soil and covering is important (subsoil application)
Continuous application (subsequent years) to build up organic matter content in the soil
43. Practical Recommendations for Faeces: Application Technique Largest benefits of faeces ? content of P and organic matter
Thus: applied at a depth where the soil stays moist (transport of nutrients)
water-holding and buffering capacity of the organic matter only fully used in moist conditions
44. Practical Recommendations for Faeces: Application Technique Digestion residues:
high ammonia content
Minimize ammonia loss through storage, handling and application
storage in covered containers
rapid incorporation into the soil.
Ash
concentrated fertilizer
careful distribution
spreading may be difficult ? mixed with a bulking agent (sand, soil)
45. Practical Recommendations for Faeces: Application Rate
46. Practical Recommendations for Faeces: Application Rate
47. Practical Recommendations for Faeces: Application Rate Application rate according to organic matter content
higher rates of application are needed to achieve effects on the soil system (structure and water-holding capacity)
High and stable organic matter content is only accomplished over longer periods of time ? continuous application, as Organic Matter mineralizes in the soil to release Nutrients
plant nutrients are mineralised and become plant-available
content of organic matter decreases
48. Benefits of using sanitised urine, faeces, greywater in agriculture
49. Adaptation to local conditions Required Information
Crops
Nutrient requirement
N:P:K Ratio of Nutrient Uptake
Yield kg/ha
Water requirements
Growth Phases
50. Adaptation to local conditions Rainfall
Climate
Slope of terrain
Ground Water Level (Distance vertical flow)
Distance to Water Bodies (lateral flow)
Soil
Concentration Macro- and Micronutrients
Content of Organic Matter
Nutrient Deficiencies, Heavy Metals, Pollutants
Exchange Capacity of the soil (CEC)
Infiltration Rate
Field Capacity
Volume/Depth of Soil
Geological Situation (Influence on ground water)
51. Conclusion: Safe Reuse of ecosan Products ? Agricultural use practises depend on
the preceding treatment and treatment efficiency
? influences characteristics (hygienic risk, nutrient content, organic matter content
) of Ecosan Products
52. Practical Recommendations for Faeces: Safe Reuse of Faeces Additional safety measures
special equipment for sanitized and un-sanitized products
handling: wear protective clothing (i.e. gloves) and wash afterwards
work treated faeces into soil rapidly
do not use improperly sanitised faeces for vegetables, fruits or root crops that will be consumed raw, excluding fruit trees.
Cover with soil
