|[[Image:Fill_and_cover_arborloo.png |right|300px]]
|}
----
[[Image:Icon_fill_and_cover_arborloo.png |right|95px]]
'''When a pit is full, it can simply be filled with soil and covered. Although there is no benefit recovered, the full pit poses no immediate health risk, and with time, the contents will degrade naturally. Alternatively, the ‘Arborloo’ is a shallow pit that is filled with excreta and soil/ash and then covered with soil; a tree planted on top will grow vigorously in the nutrient-rich pit.'''
In the Arborloo, a tree is planted on top of the full pit while the superstructure, ring beam and slab are continuously moved from pit to pit in an endless cycle (usually moved once every 6 to12 months). A shallow pit is needed, about 1m deep. The pit should not be lined as the lining would prevent the tree or plant from growing properly. Before the pit is used, a layer of leaves is put into the bottom. After each defecation, a cup of soil, ash or a mixture should be dumped into the pit to cover the excreta. If they are available, leaves can also be added occasionally to improve the porosity and air content of the pile. When the pit is full, the top 15cm of the pit is filled with soil and a tree is planted in the soil. Banana, papaya and guava trees (among many) have all proven to be successful. A tree should not be planted directly in the raw excreta. The tree starts to grow in the soil and its roots penetrate the composting pits as it grows. It may be best to wait for the rainy season before planting if water is scarce. Other plants such as tomatoes and pumpkins can also be planted on top of the pit if trees are not available.
{{procontable | proborder="1" cellpadding="5" cellspacing="0" align="center"|-! width="50%" style="background:#efefef;" | Advantages! style="background:#ffdead;" | Disadvantages|-| valign="top" |- Simple technique for all users. <br> - Low cost. <br> - Low risk of pathogen transmission. <br> - May encourage income generation (tree planting and fruit production). | convalign="top" |- Labour intensive.|}}
==Adequacy==
A cup of soil and/or ash should be added to the pit after each defecation and leaves should be added periodically. Also, the contents of the pit should be periodically levelled to prevent a coneshape from forming in the middle of the pit. There is little maintenance associated with a closed pit other than taking care of the tree or plant. If a tree is planted in the abandoned pit, it should be watered regularly. A small-fence should be constructed with sticks and sacks around the sapling to protect it from animals.
==Acknowledgements=={{:Acknowledgements Sanitation}} ==References and external links==
* Morgan, P. (2007). Toilets that make compost. Stockholm Environment Institute, Stockholm, Sweden. pp 81–90. Available: http://www.ecosanres.org
* NWP (2006). Smart Sanitation Solutions. Examples of innovative, low-cost technologies for toilets, collection, transportation, treatment and use of sanitation products. Netherlands Water Partnership, The Netherlands. pp 51.
==Acknowledgements==
{{:Acknowledgements Sanitation}}
