Appropriate Technology Technical Notes describe simple, small-scale technologies aimed at improving people's access to food, water, and shelter. Each document introduces and explains the general concept behind the technological solution, some even include instructions of how to construct your own.


  1. 2001-01-01 Often the biggest challenge faced by a tropical farmer is not in the production of a crop but rather in the preservation of the crop. Farmers may want to preserve a crop for future consumption or for sale at a time when the market will offer a higher price. Using a solar dehydrator is a simple,...
  2. 2001-01-01 This simple device provides a method of manually producing bales of hay. Small-scale farmers may be interested in this technology because hay is both easier to store and easier to transport when it has been baled. Also, baled hay retains a higher nutrient content than hay that has been cut and...
  3. 2001-01-01 Access to clean drinking water remains one of the greatest challenges in the world. The BioSand Filter is one method that can be used for purifying water at the household level. With this filter, contaminated water is filtered through a natural biological layer and then layers of sand, pebbles...
  4. 2002-01-01 A composting toilet is any system that converts human waste into compost through the natural breakdown of organic matter. The photo above shows a composting toilet from the late 1800’s. Composting toilets provide a sanitary method to recycle human waste while conserving water and protecting the...
  5. 2003-01-01 Rope can be made from cord or string or even discarded plastic bags using a simple spindle to twist the materials together.
  6. 2006-01-01 The A-Frame Level is a simple, yet accurate tool used for constructing contours on a hillside or slope. It is useful in the basic construction of hillside farming systems, such as the SALT systems, as well as for establishing level contours and drainage ditches. Level contours on a slope reduce...
  7. 2010-01-01 The purpose of this document is to show several water pump designs constructed from PVC pipe, explain how to manufacture them, and discuss pump performance and how to improve on these designs. What’s Inside: Pump Design Manufacturing Process Pump Performance Appendix
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    2010-01-01 This treadle grindstone can spin a 6” abrasive wheel (of the type used on electric tool grinders) at up to 3000 rpm by means of a single treadle operated by the person using the grinder. Although rotational speed is similar to electric grinders, power is lower therefore short or light grinding...
  9. 2000-01-01 Briquettes made from materials that cost little or no money to obtain, such as old newspaper or unutilized plant waste, can be a cost-effective alternate fuel to charcoal or firewood. This could alleviate the harsh pressures put on many forests for providing enough fuel energy to meet people’s...
  10. 2002-01-01 This simple forage cutter provides a mechanism to chop tough grasses or other forages to make them more palatable and digestible for livestock. This results in more efficient food conversion for animals and reduced wastage. It can also be used to chop materials for compost, silage, vermiculture,...
  11. 2002-01-01 Seed storage is often a problem in the tropics. However, if seeds can be properly dried, they will remain viable for a longer period of time. The seed drying cabinet described here can help improve the viability of seeds in storage. What’s Inside: Introduction Description Diagram Observations
  12. 2003-01-01 Although this document will tell you how to build a particular incubator that I have used for several years, the ideas presented here should assist in building an incubator of any capacity. The orientation here is toward solving the problems in building a kerosene fired incubator in general....