* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Observations on the breakdown of faeces in bags and buckets held
Survey
Document related concepts
Entomopathogenic nematode wikipedia , lookup
Plant nutrition wikipedia , lookup
Surface runoff wikipedia , lookup
Soil erosion wikipedia , lookup
Soil horizon wikipedia , lookup
Terra preta wikipedia , lookup
Canadian system of soil classification wikipedia , lookup
Soil respiration wikipedia , lookup
Crop rotation wikipedia , lookup
Soil salinity control wikipedia , lookup
Soil compaction (agriculture) wikipedia , lookup
No-till farming wikipedia , lookup
Soil food web wikipedia , lookup
Transcript
Observations on the breakdown of faeces in bags and buckets held within UD toilet vaults Peter Morgan and Annie Kanyemba June 2008 The materials observed were collected in a single vault urine diverting toilet where the urine was separated off to a plastic container and the faeces dropped directly into a sack contained within a 20 litre bucket held within the vault. In this technique the sacks are taken out and replaced with new empty sacks. Parts of the toilet The sack fills with a combination of faeces, soil and ash and toilet paper. Leaves or soil are added to the base of the sack before it fills. As the sack fills material lower down starts to convert into compost. When the sack is full the uppermost layers are raw material. These raw materials are covered with more soil and the sack closed off and stored in a safe place (which may be the vault itself). Over a period of months the soil organisms eat into the excreta and convert it into a soil like material. The conversion is faster if the soil is well dispersed with excreta. It is slower if larger amounts of excreta are not exposed to soil. Below a bag of material is emptied into a wheel barrow for observation. Two sacks were observed closely on 14th August 2008. The first sack had been closed off on 31st March 2008 after adding some soil, leaves and some red worms. (about 20 weeks) The second sack had been closed off on 20th May 2008 after adding some soil, leaves and earthworms. (about 13 weeks) For smaller “nobules”, the conversion was almost complete after about 4.5 months, but not complete after 3.75 months) However for larger pockets of excreta the conversion had not been completed in either sack. See next slide. Observations on the breakdown of faeces in bags held for 4.5 months (31st March to 14th August) Note the pockets of raw material had been reduced considerably and the survival of healthy “red worms” in the material. Small red worms were placed in the sack on closure together with soil and some leaves. Observations on the breakdown of faeces in bags held for 2.75 months (20th May to 14th August) Note the larger pockets of raw material had not been reduced so much and still contained much raw material. Common earthworms added to mix on sack closure appeared to have died out. Activity of red worms in shallow pit composting systems. Initial trials: Red worms being added to composting pit of Fossa alterna Activity of red worms in shallow pit composting systems. Initial trials: Red worms being added to “filling pit” of Fossa alterna Conclusions 1. The addition of soil (and ash) to excreta promotes conversion of excreta into “compost.” 2. Conversion is faster as the ratio of soil to excreta increases (the more soil the better!) 3. Conversion is faster as the area of interface (ie proximity of soil to excreta) increased. (ie a better mix helps) 4. Red worms appear to thrive in or close to raw excreta 5. Red worms are know to be good converters of waste products into good compost 6. Earthworms appear to be less tolerant of such conditions. 7. It is possible that red worms could assist in the conversion of excreta to compost in composting material being processed in urine diverting systems and also in shallow pit compost toilets (Arborloo and Fossa alterna) Overall conclusions The addition of soil and ash helps the conversion of raw excreta into a more easily managed and valuable compost. A period of at least 6 months is required for the conversion in sacks in urine diverting toilets and in shallow pits for up to one year. Red worms appear to assist the conversion and their role may become more important in the future for shallow pit and urine diverting technology options. A biological process in the composting process does require the presence of beneficial soil organisms (bacteria etc) and some moisture in the system. Care must be taken in areas where worm infections are common (eg Ascaris). Where there is doubt, the material must be buried underground (in tree pits or garden trenches) or stored in sacks.