Course 2 Unit 6 Part B – Vermicomposting Introduction to composting Teacher: Mariska Ronteltap m.ronteltap@unesco-ihe.org Course 2 Unit 6 Course 2 Unit 6 Part B: Vermicomposting By the way: there are many video clips on vermicomposting in general on YouTube.com Overview Vermicomposting is a special type of composting which uses certain earth worms Vermicomposting is already being used worlwide for treatment of organic waste, sewage sludge, manure, kitchen waste etc. Vermicomposting can also be used to treat faeces (e.g. faeces collected from UDD toilets), in order to make faeces into a valuable product The Technical University in Hamburg (TUHH) in Germany is conducting research in the field of vermicomposting of faeces, see their website (and also see next slide): https://www.tuhh.de/alt/aww/projects.html https://www.tuhh.de/t3resources/aww/fors chung/pdf/vermi_dry_toilet.pdf Source: Google Images Information sources for this presentation E-mails from Christopher Buzie in 2007 http://doku.b.tuharburg.de/volltexte/2011/1095/pdf/DissertationChristopherBuzi e.pdf PhD thesis of Moataz Shalabi “Vermicomposting of Faecal Matter as a Component of Source Control Sanitation”, TU HamburgHarburg (2006). http://www2.gtz.de/Dokumente/oe44/ecosan/envermicomposting-of-faecal-matter-as-a-component-of-sourcecontrol-sanitation-2006.pdf Website “The compost guy” (general information on vermicomposting, but not vermicomposting for faeces): www.compostguy.com wikipedia Definition of vermicomposting Vermicompost (also called worm compost, vermicast, worm castings, worm humus or worm manure) is the end-product of the breakdown of organic matter by some species of earthworm. Vermicompost is a nutrient-rich, natural fertilizer and soil conditioner. The process of producing vermicompost is called vermicomposting. The earthworm species (or composting worms) most often used are Brandling Worms (Eisenia foetida) or Red Wigglers (Lumbricus rubellus). These species are only rarely found in soil and are adapted to the special conditions in rotting vegetation, compost and manure piles. Composting worms are available from mail-order suppliers, or from angling shops where they are sold as bait. Small-scale vermicomposting is well suited to turn kitchen waste into high-quality soil, where space is limited. In addition to worms, a healthy vermicomposting system hosts many other organisms such as insects, mold, and bacteria. Though these all play a role in the composting process, the earthworm is the major catalyst for the composting process. Source: www.wikipedia.org Course 2 Unit 6 Vermicomposting - basics Vermiculture (derived from the Latin word “vermis” meaning worm) involves the mass production of earthworm for waste degradation, and composting with “vermicast” production Earthworms are the “intestines of the earth”! They occur in diverse habitats especially those which are dark and moist Organic materials like humus, cattle dung and kitchen wastes are highly attractive for some species Types of action of the earthworms Physical/mechanical: – Substrate aeration and mixing due to the movement of the worms inside the substrate as well as actual grinding – Keeps organic waste constantly aerated and achieves cooling saves costs on mechanical process units for mixing used in conventional (hot) composting Biochemical: – Microbial decomposition of the substrate in the intestines of the earthworms What do the earthworms do? 1. Maintain aerobic conditions in the mixture 2. Ingest solids 3. Convert a portion of the organics into worm biomass and to respiration products 4. Expel the remaining partially stabilised matter as discrete material (earthworm faeces or “castings”) 5. Worms and aerobic mesophilic microorganisms act symbiotically to accelerate and enhance the decomposition of the organic matter Properties of end product from vermicomposting Very finely structured, uniform, stable and aggregated particles of humified organic material Excellent porosity, aeration and water holding capacity Rich in available plant nutrients, hormones, enzymes and (benign) microbial populations Mostly pathogen-free: Plant and human pathogens are killed during passage of the earthworm gut Earth-like, soil building substance that forms a beneficial growing environment for plant roots Valuable and marketable product Source: Google Images Course 2 Unit 6 Degree of organic matter degradation depends on: 1. Portion of the waste that is degradable 2. Maintenance of aerobic conditions 3. Absence of toxic compounds Source: Google Images Vermicomposting is practically odour-free Earthworms release coelomic fluids into the decaying waste biomass which have anti-bacterial properties and kill pathogens By creating aerobic conditions, the release of foul-smelling hydrogen sulphide from anaerobic microorganisms is inhibited So what’s the difference between conventional composting (also called “hot composting”) and vermicomposting? Hot composting Vermicomposting See next slides Source of the photo: http://www.compostguy.com/composting/hot-composting-vsvermicomposting/ -- very informative website! Differences between vermicomposting and (hot) composting (slide 1 of 2) Process variable Vermicomposting Conditions Hot composting Aerobic Process temperature 15 - 25ºC 50-70ºC Type of temperature Ambient to mesophilic (<35ºC) – otherwise worms will be killed Thermophilic (at least for part of the time) Method of operation Apply waste frequently in thin layers (continuous operation rather than batch) Stack waste material in large piles so that heat produced is retained in pile (usually batch operation) Course 2 Unit 6 Differences between vermicomposting and (hot) composting (slide 2 of 2) Process variable Vermicomposting Hot composting Earthworms Present in large quantities Only present at beginning (die off at temperature in pile > 35°C) Pathogen destruction mechanism Passage through worm gut (biochemical digestion) Elevated temperature over extended period (> 1 week) and action of microorganisms Final product Vermicompost or vermicast; microbiologically active (this is good for the soil) Compost; relatively little microbial activity Vermicomposting: pros and cons compared to hot composting Pros 1) Tends to be somewhat less laborintensive - no turning/aerating necessary (worm activity helps to mix, fragment and aerate materials) 2) Cooler temperatures help to conserve nitrogen 3) Higher moisture contents not an issue (and actually preferred) 4) Materials can be constantly added (no need to stock pile in preparation for next ‘batch’) 5) Size of system unimportant - ideally suited for both indoors and outdoors 6) Considerable evidence to indicate that vermicomposts have beneficial properties not found in hot composts 7) Under ideal conditions, wastes can be processed very quickly Cons 1) Won’t kill seeds (and although there is a fair amount of evidence to indicate pathogen destruction, more research is required) 2) More space required to process similar amounts as hot composting - need to be careful with amount added (since excess heat will kill worms) 3) Outdoor systems much more limited by cold weather 4) Worms need to be separated from compost 5) Worms (although quite resilient) do require some attention and proper care. Source: http://www.compostguy.com/composting/hotcomposting-vs-vermicomposting/ Hot composting: pros and cons compared to vermicomposting Pros 1) Enables processing of larger quantities of materials in a smaller area 2) Can proceed relatively quickly under ideal conditions 3) Can kill weed seeds and pathogens 4) On a large scale can proceed easily in cold weather Cons 1) Can be labor-intensive (piling wastes, turning pile etc) and require more attention 2) Heat can kill off many beneficial microbes 3) May require some stockpiling until sufficient materials available for ‘batch’ 4) Heating can lead to considerable nitrogen loss Source: http://www.compostguy.com/compostin g/hot-composting-vs-vermicomposting/ Vermicomposting can speed up the process of composting Source: Claudia Wendland, TUHH (Hamburg Technical University) presented at Bulgaria ecosan seminar, April 2007 How to do vermicomposting of wet faecal matter “ For the treatment of wet faecal matter vermicomposting will be a good choice. You can try to find the regional species when you inquire which worms are found in dung, maybe there is a worm farm around (often used for biowaste composting). When you put them in, leave them with a good amount of their original compost so that they can work from there into the material. Make sure the heap is not getting too dry, some controlled moisturing may be required. Six months will give excellent compost, due to the origin of the faeces from so many different people I recommend to work it into the ground with care on a non-food field.” Source: Ralf Otterpohl (TUHH Hamburg University, Germany), Ecosanres Discussion Forum, 21 March 2007 Course 2 Unit 6 How to do vermicomposting if the faeces are very wet? “The trick is to properly manage the temperature and moisture content of the material. – For wet faeces you collect from UDD toilets which are not properly used, I recommend you put it in filter sacks and allow to drain for about a week. – In the absence of a filter sack, you could use the closelywoven large African fibre baskets.” Source: Chris Buzie (PhD student at TUHH Hamburg University, Germany), Ecosanres Discussion Forum, 27 March 2007 Course 2 Unit 6 How to find the right earthworms? “Look around for a composting heap. Dig out the worms you find in there (as many as possible) and add them in the drained faeces. The species of earthworms you are likely to encounter in compost heaps in tropical countries and which will likely be suitable for treating faecal material are: - Eudrilus euginiae (fast growing and capable of processing large quantities of organic wastes rapidly but easily damaged by handling) and - Perionyx excavatus (also very prolific and not easily damaged). I am not suggesting that you take the pains in identifying these organisms before using them as any earthworms you'll find in the compost heaps around you will suffice. You do not need to dig deep into the heaps to look for them as the earthworms will always congregate at the top layers where temperature is lower.” Source: Chris Buzie (PhD student at TUHH Hamburg University, Germany), Ecosanres Discussion Forum, 27 March 2007 Here is an idea: How about starting your own vermicomposting process in your kitchen? From: Marieke Heijnen in June 2007 (former online course participant) “Hi everyone, I just wanted to share my excitement of my new pets with you all- I became very intruiged by the whole vermicomposting since the course and now have a multi-story worm house in my kitchen. they don't smell, they're great with kitchen waste (even my coffee grounds!) and soon they'll start making very nutritious liquid which will make my plants very happy. I took the easy way out as I ordered a 'worm starters kit' via http://www.wigglywigglers.co.uk (I got the can-o-worms) http://www.reln.com.au/product_info.php?pid=9&cid=3 I already have excited many of my friends, and hopefully my worms will breed lots so I can give some to others and also put them in outside compost heaps! So- recommend it to everyone, it's very fun! Take care, Marieke “ (marieke.heijnen@gmail.com) Research project: The effect of vermicomposting on presence of helminth ova in human faeces (November 06 to February 07) Actual vermicomposting of organic wastes in Manresa (XU Farm) Source: Robert J. Holmer, Analiza U. Miso Periurban Vegetable Project (PUVeP) Xavier University College of Agriculture Cagayan de Oro City, Philippines http://puvep.xu.edu.ph/ (see following slides for more information) Course 2 Unit 6 Example of current research in this field: EFFECT OF VERMICOMPOSTING ON THE PRESENCE OF HELMINTH OVA (Necator americanus, Trichuris trichiura, Ascaris lumbricoides) IN HUMAN FAECES by: Michael Z. Nuesca Xavier University College of Agriculture Cagayan de Oro City, Philippines Presented at: International Conference on Sustainable Sanitation: Eco-Cities and Villages 26-31 August 2007, Dongsheng, China http://www.ecosanres.org/icss/proceedings-presentations.htm The full presentation is provided under Assigned Reading Nuesca’s presentation: Methodology Randomized Complete Block Design (2 factorial with 4 replications) – Factor 1: Dried human faeces collected from two UDD toilets – Factor 2: Vermicomposting Nuesca’s presentation: Result Hookworm (Mean) With vermicomposting Day 1 = 9.69 Day 30 = 4.06 Day 60 = 7.13 Number of Necator americanus per 2 grams substrate 35.00 30.00 25.00 wit h vermicom posting 20.00 15.00 wit hout vermicom posting 10.00 5.00 0.00 1 30 60 Vermicomposting (days) Without vermicompsting Day 1 = 9.38 Day 30 = 13.5 Day 60 = 30.31 Nuesca’s presentation: Conclusion After 60 days, – Vermicomposting significantly reduced the number of Ascaris ova below the threshold level of USEPA. – Whipworm ova were fully eliminated regardless of treatment. – Number of hookworm ova were significantly less in the vermicomposting treatments; however, above the threshold level of USEPA. Course 2 Unit 6 Nuesca’s presentation: Recommendation Further researches on: – Longer- period exposure – Higher density of earthworms – Effect of vermicomposting on other faecal pathogens – Effect of vermicast on growth of different crops And at the end: A little real life story about backyard vermicomposting in the Philippines “Today was composting day in our garden. Our gardener sieved the fresh compost from one of our 2 compost boxes, bagged the fine stuff into rice bags and mixed the rough, not yet fully composted bits with the content of the other box. He has done that numerous times and usually he puts the worms that are caught in the sieve together with the rough material into the second box. Today, he could not finish the job and his 20 year old son, a University Student jumped in for him. When my husband came home the job was done and he asked the young man if he had also collected the worms and put them into the other box. Well, he had not… He had killed all my precious African Nightcrawlers that are such good compost makers! He thought they were rather ugly and harmful creatures.” Ulrike, where did you get the worms from? “Well, I sort of imported them when I started with the compost. One of my German colleagues from DED had established biowaste composting on the landfill of a nearby town. He offered to get some of their compost and advised me to mix it with our garden and kitchenwaste. The worms hatched from the worm eggs that were in the compost (not only ascaris survive in soil ;-)). They grew very well and are really great compost makers. “ Posting by Ulrike Lipkow, GTZ Philippines, during March-June ecosan online course (in May 2007)