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Urban agriculture and fertiliser trials

Urban agriculture and fertiliser trials

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Urban agriculture and fertiliser trials

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  1. Course 3 Unit 2 Urban agriculture and fertiliser trials Teacher Mariska Ronteltap

  2. Course 3 Unit 2Urban agriculture and fertiliser trialsPart A: How to apply ecosan products in agriculturePart B: Introduction to urban agriculture Part C: Examples for agricultural reuse research trials

  3. This unit deals with which part of the sanitation system?

  4. Course 3 Unit 2 Course 3 Unit 2 Part A: How to apply ecosan products in agriculture Example in Sweden: See video clip with employee at Nacka Community Greenhouse for flowers and plant production, where urine is used as a fertiliser, recorded in 2004 as part of the movie by WASTE (The Human Excreta Index): mms:// (this video clip is also on the course DVD) Applying urine to the soil next to a young maize plant (Morgan, 2007, p. 86)

  5. Awareness raising and education on hygiene and reuse aspects Adequate treatment for sanitisation (e.g. storage, drying, composting) Suitable handling (with security measures, gloves, boots, handwashing etc.) Limitation to specific vegetables and field crops, or to specific vegetation periods, depending on treatment Course 3 Unit 2 Multiple-barrier concept to secure safety in reuse See also Appendix (combination of health protection measures) Spreading of urine before sowing in Sweden

  6. From: Course 1 Unit 2 Reminder: Nutrient excretion by humans is directly linked to diet N Rules of thumb for nutrient cycle: • We excrete the same amount of nutrients that we take up in our diet (except for children who retain a small proportion for 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! Excreta Diet N P P Source: Jönsson et at. (2004)

  7. Basically (same info as on previous slide, just in other words): Course 3 Unit 2 Excreta and food production = Amount of excreted plant nutrients per person Amount of consumed plant nutrients per person • The amount of excreted plant nutrients can be calculated from the food intake • If all excreta, biowaste and animal manure are recycled, the fertility of the arable land can be maintained • Rule of thumb: Distribute the excreta of people on an area equal to that used for producing food for the people Source: Jönsson et al. (2004) Source of this slide and the next two: Heeb et al. (2007)

  8. Reminder: fertiliser macronutrient production by humans Source: Jönsson et al. (2004), see also lecture on “Characteristics of urine, faeces and greywater” (Course 1 Unit 2) • * Amount of N, P and K needed (in kg/year) to grow 250 kg of maize (this 250 kg maize is roughly equal to the food intake of one person per year, see also next slide)

  9. Course 3 Unit 2 Rules of thumb about food production • If all urine is collected, it suffices to fertilise 300 – 400 m2 per person (for most crops the maximum application rate before risking toxic effects it at least four times this dosage) • This would be sufficient to grow about 230 kg of cereal crops per year • Recommended calorific food intake: 2500 kcal/cap/d (for males) • Carbohydrates energy density: 4 kcal/g • One male needs ~ 228 kg carbohydrates per year • But keep in mind: • need to consider losses of nutrients during agricultural production • the balances don’t work out so well for societies where the people eat a lot of (grain-fed) meat – unless the animal manure is also returned to the land

  10. Guiding principle for fertilisation with ecosan products “We are fertilising the soil, not the plant!”  ecosan products not to be used on plants directly but on the soil in which the plants are grown

  11. Urine application at a research field at CREPA headquarters in Ouagadougou, Burkina Faso (Photos taken during Refresher Course on ecosan in October 2006)

  12. Urine is applied in a furrow about 10 cm away from the plants Linus Dagerskog, a junior professional of SEI (Sweden), during his posting at CREPA

  13. Course 3 Unit 2 Role of faeces as an organic fertiliser • High concentrations of P and K • Plant availability of nutrients in faecal matter is lower and slower than that of the urine nutrients (N and P stems from undigested matter) • Organic matter in faeces degrades and organic N and P become available • Organic matter is beneficial because: • Improves soil structure • Increases the water-holding capacity and ion-buffering capacity of the soil • Supports soil microorganisms by serving as an energy source Source: Jönsson et al. (2004)

  14. Benefits of compost for soil fertility (1/2) • Compost* improves soil structure: An ideal, friable garden soil consists of airy crumbs in which particles of sand, clay and silt are held together by humic acid. Compost helps these particles to form. • Compost increases the water-holding capacity of soil: • While 50 kg of silt holds 12 kg of water and 50 kg of clay holds 25 kg of water, 50 kg of compost holds 100 kg of water. • A soil rich in compost requires less watering, and plants growing in compost will better withstand drought. • Compost moderates soil temperatures: Adding compost to soil tends to keep the soil from heating up or cooling down too rapidly. Soil darkened through the addition of compost absorbs the light and moderates its effect on the growing plant and beneficial soil microorganisms. • Compost breaks up organic matter into the basic elements that plants need: Compost is teeming with microorganisms, which continually break down organic matter. * This includes compost made from faeces, faecal sludge and/or organic solid waste (see also Course 2 Unit 6 (Introduction to composting))

  15. Course 3 Unit 2 Benefits of compost for soil fertility (2/2) • Compost returns to soil what agriculture takes out of it: Compost is made up of decaying matter, and it includes nearly every chemical a plant needs, including boron, manganese, iron, copper, and zinc which are not present in commercial fertilisers. • Compost releases nutrients at the rate plants need them: Compost acts as a storehouse for nutrients, and slowly releases the nutrients throughout the growing season as the organic material decomposes in the soil. • The compost layer prevents the surface from drying out, which increases uptake of nutrients and improves the growth of plants. • Compost can neutralise soil toxins and heavy metals: Compost binds metals such as cadmium and lead, making it difficult for plants to absorb them. • Compost reduces pests and disease: Compost improves plants' ability to withstand attacks by disease and insects by enhancing naturally occurring microbial agents. Furthermore, it reduces the effects of soil-borne pathogens and reduces the amount of plant parasites and nematodes in the soil. Source: Esrey et al. (2001), p. 47

  16. Visual evidence for agricultural benefits of ecosan products compost improved soil none faeces & urine urine untreated soil Maize (corn) after one week without water It is this sort of evidence that will convince people (especially farmers) of the benefits of ecosan! Source: GTZ presentations

  17. without ecosan products Course 3 Unit 2 with ecosan products The dark green colour comes from more nitrogen uptake Source: Morgan (2007), p. 84

  18. Increased yield for maize (corn) with ecosan products Source: Morgan (2007), p. 84

  19. Effect of urine treatment on green leafy vegetables (dilution 5:1 (2 L urine and 10 L water); watering and urine application can be done together) Spinach yield increased by a factor of 3.4 after treatment with urine twice a week (after 28 days) Source: Peter Morgan on EcosanRes Discussion Forum, 8 Feb 2006 (Zimbabwe), see also Morgan (2007), p. 81 & 82 Rape yield increased by a factor of 5 after treatment with urine twice a week (after 28 days) Diluted urine was applied during the growth phase

  20. How to apply sanitised urine as a fertiliser (1/2) • Urine is a quick-acting nitrogen-rich complete fertiliser • Urine is best utilised as a direct fertiliser for N-demanding crops and leafy vegetables (e.g. spinach, cauliflower, ornamental flowers and maize) • Urine should be applied close to, on or incoporated into the soil • Urine may act as an insecticide/fungicide • E.g. killed banana weevils in Tanzania and Uganda (source: Dave on Ecosanres Discussion Forum, 18 August 2006 + answers from others)

  21. Course 3 Unit 2 How to apply sanitised urine as a fertiliser (2/2) • Apply nutrients once or twice per growing season (this means urine storage is needed) • Apply prior to or at the time of sowing/planting • Fertilisation should only take place up to 2/3 or ¾ of the time between sowing and harvest • Waiting period of 1 month between fertilisation and harvest is recommended for all crops eaten raw • Whether urine is best applied diluted with water or undiluted is still being debated at present Source: Jönssonet al. (2004) For further information on this topic see also Morgan (2007), Section 11

  22. Faecal matter is rich in P, K and organic matter Organic matter and ash, which are often added to the faeces, increase the buffering capacity and pH of the soil Should be applied and mixed into the soil before cultivation starts Application rate can be based on rates for P-based fertilisers Avoid faeces as fertiliser for growing vegetables which are eaten raw Must be applied at a depth where the soil stays moist (dissolve P to make available to plants) How to apply sanitised faecal matter as a fertiliser For further information on this topic see also Morgan (2007), Section 10

  23. “Dried faeces are thrown into the seed hole.” (dried faeces from UDD toilet) Source of this slide and next: NGO training, Visayas, Philippines (see powerpoint file under Assigned Reading). Provided by Glenda Sol.

  24. “Some people prefer to use a shovel for moving dried faeces.” Note: It may be recommended to wear gloves and boots when performing this type of work (multiple-barrier approach)

  25. Summary for using ecosan products (sanitised urine and faeces) in agriculture

  26. Course 3 Unit 2 Reuse of sanitised greywater in agriculture • Treated greywater can be used to irrigate crops • Greywater contains some P (from detergents) but little N • See literature on treated wastewater reuse (but greywater of ecosan approach would have lower volume and much lower pathogen content than domestic wastewater) • See also literature on irrigation • For large-scale irrigated agriculture the quanitty of greywater available may be insufficient (depending on the number of households contributing) • Remember: irrigation in agriculture is a major consumer of water Note: keep in mind possible impact of salinity and sodicity (sodium content) contained in greywater on soil structure (see also MSc research project by George Munggai in Kenya – in Extra Materials)

  27. Example for greywater reuse in low-income areas of Lima (Peru) to grow plants to feed rabbits, which are then eaten by the families See video clip on this topic, recorded in 2004 as part of the movie by WASTE (The Human Excreta Index): mms:// (this video clip is also on the course DVD)

  28. Hormones and pharmaceutical residues in ecosan products (mainly urine) can be considered a less urgent problem for reuse because… • Vegetation and soil microbes can degrade hormones and pharmaceuticals • It is far better to recycle urine and faeces (with their hormones and pharmaceuticals) to arable land than to flush them into recipient waters • Retention time of wastewater in conventional WWTPs is too short to degrade these substances • Pharmaceutical substances have been detected for decades in groundwater of Berlin which is Berlin’s source of drinking water • Aquatic systems have never before been exposed to mammal hormones in large quantities Source: Jönssonet al. (2004)

  29. Four aspects to consider regarding pharmaceutical residues (PhaR) release via urine fertilisation (1/2) • Its composition depends of people urine is coming from. Urine of hospitals is not recommended to be used in agriculture. But still source separated collection of urine in hospitals could be an advantage to eliminate PhaR from wastewater more effectively. More and more details regarding appropriate techniques become available (Tettenborn et al. (2006)). In contrary, urine collected in small households and used within them is not considered to impose any risks. 2. It is important to store urine over some time. Due to time and pH changes via storage PhaR are destroyed up to a certain degree (Strompen, S. et al. (2003)). Additionally, certain PhaR are sensitive regarding sunlight and destroyed via photodegradation (Buser, H. et al. (1998)). 3. Soil ecoystems can take more than aquatic ecosystems. They are much more stable and degrade PhaR to a certain extend in soil as was shown in investigations dealing with veterinary pharmaceuticals in animal manure (Grote, M. et al. (2004)). 4. Additionally, timing and type of crops fertilized with urine is important.

  30. Continued from last slide Regarding the risk of PhaR release via urine fertilization the following aspects should be Still many aspects are not discussed finally and further investigations are needed to clarify remaining questions. But source separation systems are a promising option to avoid the release of PhaR into the environment. Additionally, a lot of fruitful effects should be possible by combining source separation and conventional wastewater treatment systems. E.g. by separating urine a more effective treatment of pharmaceuticals in this separated stream becomes possible and wastewater treatment plant is disburdened by loads of nitrogen and other nutrients which are hold back at the same time. The ideal situation has to be designed according to local conditions.---------------Source: Hammer, M. & Otterpohl, R. (2006): Pharmaceutical residues in the environment – advantages and disadvantages of conventional wastewater treatment and ecological sanitation systems. In: Proceedings of 4th International Water Forum "AQUA Ukraine - 2006"and International Forum "Ecological Technologies - 2006", September 19th - 21st, 2006. Kiev, Ukraine, pp. 474-477. Website from where you can get the full paper + many more: (See also discussion on EcosanRes discussion forum 17 Oct 2007)

  31. Another point on the question of pharmaceutical residues and hormones in urine • We currently apply ample animal manure to the land (e.g. the Netherlands, Europe) • This animal manure also contains hormones and pharmaceutical residues because of our intensive animal husbandry practices • For some reason, nobody seems to question the risks involved in that (??) See also the paper from Hammer and Clemens (2007) on this topic, under Extra Materials

  32. What if people are still really worried about eating food fertilised with human excreta? • You can use human excreta also on other types of crops, which are not eaten by humans, e.g. • Flowers • Potted plants • Fibre-producing plants (e.g. hemp) • Fodder crops • Oil-producing plants, e.g. olive trees • Trees

  33. Course 3 Unit 2 Course 3 Unit 2 Part B: Introduction to urban agriculture

  34. What is the definition of “urban”? • The definition of “urban” is not straight forward and varies from country to country • Some countries use a minimum number of population (e.g. Zambia: > 5000; Senegal: > 10,000) or a minimum number of dwellings (Peru: > 100) • UNStats definition: 75% of economic activities are non-agricultural • European countries: the area based on urban-type land use, not allowing any gaps Source: MSc thesis de Silva (2007), p. 8 – provided in Extra Materials

  35. Urban agriculture Definition = production of crops and/or livestock on land, which is administratively and legally zoned for urban uses • can be “illegal cultivation of public land” • there may be a reluctant tolerance of urban agriculture (recognition of increased pressures on the urban poor) Yemen: crops in old Sana'a town • Sometimes residents can apply for permission to use designated land for the cultivation of crops Source: Gumbo (2005), p. 11 & 135 See Chapter 1 and Chapter 3 under Extra Reading

  36. Should urban areas have agriculture? • One MSc student once said to me: “If agriculture is practised in an urban area, this area should no longer be called “urban”!?” – Is there a contradiction between the terms “urban” and “agriculture”? • What do you think?

  37. Urban agriculture activities • In cities such as Lusaka and Dar es Salaam as much as 50% of the food is produced within the city • Land types used, e.g. in Harare, Zimbabwe: railway reserve, moderate slope, steep slope, roadside, seasonally waterlogged drainage ways Source: Gumbo (2005), p. 12 & 136 See Chapter 1 and Chapter 3 under Extra Materials

  38. Course 3 Unit 2 On-plot and off-plot urban agriculture – Example Harare, Zimbabwe Source: Gumbo (2005), p. 136 See Chapter 3 under Extra Materials

  39. Example cities in developing countries where urban agriculture is well documented • Accra (Ghana) • Lima (Peru) • Kampala (Uganda) Further information on these and other cities: • See also the EU project SWITCH (led by UNESCO-IHE), where one work package is entitled “Use of urban water (fresh and wastewater) for urban agriculture and other livelihood opportunities”. • • SWITCH = Sustainable Water Management Improves Tomorrow's Cities' Health • Also see the literature review of the MSc thesis of de Silva (2006), p. 43 – 63 (for Accra and Lima)

  40. Urban agriculture or allotment garden in Ede, The Netherlands (note proximity to railway line), January 2007

  41. Resource Centre for Urban Agriculture in the Philipines • The Periurban Vegetable Project (PUVeP) is a research and outreach unit of Xavier University College of Agriculture, Cagayan de Oro City, which started its operation in October 1997. • PUVeP provides research, training and education related to urban natural resources management and food production in the city • The following 23 slides were kindly provided by Robert Holmer, director of the PUVeP, from his presentation at the GTZ Ecosan Symposium 26-27 October 2006 in Eschborn, Germany

  42. Course 3 Unit 2 Allotment Gardens • Community gardens are defined as gardens where people share the basic resources of land, water, and sunlight. This definition includes both allotment and common gardens. • Allotment gardens: the parcels are cultivated individually • Common gardens: the overall area is tended collectively by a group of people (in German: “Schreber-Garten”, from a Dr. Schreber in the 19th century!)

  43. Allotment Garden in UK, Germany and Switzerland

  44. Course 3 Unit 2 Reichstag, Berlin (around 1900 shortly after it was built)

  45. Reichstag, Berlin (April 1945) – end of World War II

  46. Reichstag, Berlin (spring 1946): Urban agriculture in the centre of Berlin (people were starving)

  47. Course 3 Unit 2 Reichstag, Berlin (spring 1946)

  48. Course 3 Unit 2 Reichstag building, Berlin (2006) – no more urban agriculture in this particular area of Berlin (but allotment gardens are still popular in Berlin!)

  49. Case Study: Allotment gardens in Cagayan de Oro, Phillipines • Seven areas in the city made legally available to 99 urban poor families for production of crops • Two of them are located within the premises of public elementary schools • Integrates aspects of solid waste management, ecological sanitation, participatory land use planning and community organizing

  50. Methodology for pilot allotment gardens • Minimum of 8 individual allotment units with 288 m2 each (gross 3000 m2) • Area is fenced, with entrance, bodega and water supply • Surrounding areas can be planted with border crops • Contains a compost heap for biodegradable household wastes and urine-diverting dry (UDD) “ecosan toilet”