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Arborloos




The Arborloo is the simplest type of EcoSan toilet. It’s rather like a short-life shallow pit latrine, but it’s specifically designed to maximize the growth of high-value trees − fruit trees, for instance, or medicinal trees (see below).

Arborloos were developed by Dr Peter Morgan and described in his 2007 book:
Toilets that Make Compost:
Low-cost Sanitary Toilets that Produce Valuable Compost for Crops in an African Context.

Read chapter 3 of this book Arborloo
− The Single Pit Compost Toilet. 

Also by Peter Morgan: The Arborloo Book: How to make a simple pit toilet and grow trees or make humus for the garden.


An Arborloo functions like this: a shallow pit (0.8 m dia. and 1−1.5 m deep) is dug and a coverslab and portable superstructure (made from local materials) placed over it. This Arborloo latrine is used for 6−12 months (soil, leaves and/or ash are regularly added to the pit to accelerate the composting process − ash is a good source of potassium), after which time a new pit is dug and the superstructure placed over it. Soil is added to the full pit to just above ground level and a young tree is then planted; its roots grow down into the composted excreta/soil/ leaves/ashes in the pit and, as a result, the tree grows quickly and soon provides an income for the farmer. This process is repeated until the farmer has an orchard. Schematically an Arborloo works likes this (this is Figure 2.1 of Peter Morgan's book Toilets that Make Compost; see also pictures at bottom of page):
Arborloo
Why are Arborloos such a good idea? Well, they're very simple and very cheap, there’s no handling of the excreta even when composted, and the trees that grow in the full pits produce high-quality crops that increase rural people's incomes, as described in the following papers: 

Rapid Assessment of CRS Experience with Arborloos in East Africa (CRS, 2010)

Ecosan at low cost – with the potential for upgrading (Peter Morgan, Waterlines, 2007).  Here’s what Claire Tawney (the editor of Waterlines) says: “It may seem that the complexity of ecosanitation may make it unaffordable by the poor, but Peter Morgan describes how the very simplest model – the Arborloo – is actually easier to build than a pit latrine.”

The Arborloo Book for Ethiopia (Peter Morgan, 2007)

40,000 eco-toilets [Arborloos] in Ethiopia in 4 years: What makes it work? (34th WEDC Conference, 2009)

Low-cost Arborloo offers Ethiopians health and agriculture benefits (Waterlines, 2007). There are over 12,000 Arborloos in Ethiopia and they each cost ~USD 5−10.

Arborloo (SOIL webpage)

Waste Not, Want Not (IPS, 2007)

Ayo's Secret Garden (CRS webpage)

Food Gardens (Africa Research Bulletin, 2007)

Lessons from a low-cost ecological approach to sanitation in Malawi (WSP, 2007) Quote: … the simplest and most widely used [EcoSan system] is the “Arborloo”, which is popular particularly among women because it is relatively simple to construct.

Peter Morgan’s conference papers (2001−)
Ecological sanitation: Many approaches to a varied need
(presentation at AfricaSan 2008, Durban, February 2008)

Fertilizer Use in African Agriculture: Lessons Learned and Good Practice Guidelines (World Bank, 2007) − you can now see why Arborloos are such a good idea.  

►Arborloos are excellent for use in Africa and Asia where the average farm size is only 1.6 ha (see: Small Farms: Current Status and Key Trends: Information BriefWye College, 2005)

Arborloos are a bit like the “fossas migratórias” (mobile latrines) developed to fertilize food trees in the Amazon rainforest of Brazil − details here.  

Ecological Toilets: Start simple and upgrade from Arborloo to VIP (by Peter Morgan, 2009)


What trees to grow?

It's best to grow high-value trees. You really need to consult a local expert (local people are pretty expert too), but here are some webpages and papers to start with:


Tree domestication programme in Africa helps families out of poverty (IFAD webpage) 


Cameroon: tree domestication boosts family income (IFAD webpage)

[IFAD = International Fund for Agricultural Development]

These two IFAD webpages do not refer to Arborloos but rather to the huge advantages to small-scale farmers who grow high-value trees. The second webpage describes a joint IFAD-World Agroforestry Centre (ICRAF) project

ICRAF defines agroforestry as focusing “on the wide range of working trees grown on farms and in rural landscapes. Among these are fertilizer trees for land regen- eration, soil health and food security; fruit trees for nutrition; fodder trees that improve smallholder livestock production; timber and fuelwood trees for shelter and energy; medicinal trees to combat disease; and trees that produce gums, resins or latex products. Many of these trees are multi-purpose, providing a range of benefits.”

Basically any tree can be grown in an Arborloo pit, but it makes sense to grow ones that increase rural incomes.

A few references on medicinal trees and plants:

Indigenous Fruit Trees in the Tropics: Domestication, Utilization and Commercialization (World Agroforestry Centre, 2008)

Focus on... Tree crops (New Agriculturist, 2006)

Cultivating 'Cinderella' trees (New Agriculturist, undated)

Branching out - safou goes global (New Agriculturist, 2007)

Sustainability of harvesting Prunus africana bark in Cameroon: a medicinal plant in international trade (UNESCO, 1993)

An economic evaluation of medicinal tree cultivation: Prunus africana in Cameroon
(UNESCO, 2002)  

A Manual of Medicinal Trees [in India] (Agrobios, Jodpur, 2003)

A Handbook of Trees of Nepal: Timber, Fodder, Fruits, Medicinal, Ornamental and Religious (Vedams eBooks, New Delhi, 2002)

Neem: A Tree for Solving Global Problems (BOSTID, 1992)

Jojoba: New Crop for Arid Lands, New Raw Material for Industry (BOSTID, 1985)

The importance of medicinal plants (Unasylva #140, FAO, 1983)

Medicinal Plants for Conservation and Health Care (FAO, 1995)

Trade in Medicinal Plants (FAO, undated − but 2003 or later)

WHO Guidelines on Good Agricultural and Collection Practices for Medicinal Plants (WHO, 2003)

Antioxidant and free radical scavenging activities in extracts from medicinal trees used in the ‘Caatinga’ region in northeastern Brazil (Journal of Ethno- pharmacology, 1999)

Re-examining hypotheses concerning the use and knowledge of medicinal plants: a study in the Caatinga vegetation of NE Brazil (Journal of Ethnobiology and Ethnomedicine, 2006)

A note of caution:
Agroforestry for livelihood enhancement and enterprise development (ACIAR, 2007)

Arborloo Arborloo fruit tree

         Arborloo superstructure                                  Papaya (Carica papaya) tree
                                                                                         growing in old Arborloo pit