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VITA - Volunteers in Technical Assistance

This is a series published in the 1980s by Volunteers in Technical Assistance to provide an introduction to specific state-of-the-art technologies of interest to people in developing countries. The papers are intended to be used as guidelines to help people choose technologies that are suitable to their situations. They are not intended to provide construction or implementation details. People are urged to contact a knowledgeable organization for further information and technical assistance if they find that a particular technology seems to meet their needs.

The papers in the series were written, reviewed, and illustrated almost entirely by VITA Volunteer technical experts on a purely voluntary basis. Some 500 volunteers were involved in the production of the first 100 titles issued, contributing approximately 5,000 hours of their time. VITA staff included Leslie Gottschalk and Maria Giannuzzi as editors, Julie Berman handling typesetting and layout, and Margaret Crouch as project manager.

Permission has been granted by the current holder of Intellectual Property Rights for VITA content, Relief International, to publish the VITA library on ECHOcommunity.

Please note that re-release of these documents is a work in progress where we are recovering images and tables from archival documents.

127 Issues in this Publication (Showing issues 139 - 128) |

Understanding Solar Energy - 1985-01-01

Developing countries are in a particularly good position to use solar energy because so many receive an abundance of sunshine. More important, the inhabitants of these countries are frequently scattered over vast areas, making access to electricity or conventional fossil fuels difficult as well as expensive. Many solar systems are easily built and operated, thus providing a readily available source of energy at an affordable price. People in poorer regions of the globe, moreover, need energy primarily for low-temperature applications--cooking food, drying crops, and purifying water--to fulfill their most basic human needs. Solar energy can satisfy these low-temperature needs and give Third World inhabitants a welcome alternative to the burning of traditional fuels: wood, dung, and agricultural waste (biomass).

Understanding Solar Cookers And Ovens - 1985-01-01

In many equatorial regions, native trees and bushes are being cut at an alarming rate to meet the growing demands for agricultural land, industry, and fuelwood and charcoal. The environmental consequences of this deforestation are severe, ranging from soil erosion and climate changes to flooding and the destruction of farmland. Moreover, dwindling supplies of wood mean that people must spend more time and energy in the search for cooking fuel.

One alternative is to use kerosene, gasoline, or liquified petroleum gas. But these are often imported (hence expensive) and transporting them to remote areas is usually difficult.

The next obvious alternative is to use the sun, particularly in equatorial regions where solar energy is abundant. However, although workable solar cookers have been developed, many have serious limitations. For example, except for the indirect cookers, most can only be used outdoors and during the day (and often only when the sun is high), most have to be adjusted every 10-15 minutes to keep pace with the moving sun, and most are suitable only for slow cooking and stewing. In addition, some designs can only accommodate one cooking pot.

Since even the best aren't as fast as stoves using conventional fuels, they are most suitable in conjunction with traditional methods, (i.e., using a solar cooker during the day and a fuel-burning stove at night, thereby conserving fuel and helping to alleviate the deforestation problem).

Solar Cooker - 1967-01-01

The VITA Solar Cooker was especially designed to be sturdy, relatively easy to make, easy to repair, and low in cost. It uses the principle of the Fresnel reflector which concentrates light and heat by using several simple reflecting surfaces. Most other cookers use a doubly-curved reflecting surface. The VITA Fresnel design has a number of advantages:

  • It gives a broad uniform focal region the size of the cooking pot rather than a sharp, intense spot of heat, making it safer and more efficient;
  • Rings can be added or removed to increase or decrease the cooker's power output;
  • The solar cooker described in this manual is designed to give enough heat for the cooking needs of a medium-sized family (3-5 children),
  • to use cheap readily available materials. In the United States the materials used are mainly Masonite sheet, aluminized Mylar, wood, and iron strip. In both the United States and Morocco, the cost of materials is about three dollars ($3.00). In developing countries the Mylar will have to be imported but it is lightweight and inexpensive,
  • to be as simple as possible.

Understanding Non-Fuel Uses Of Wood Wastes - 1986-01-01

The use of waste wood is as old as humankind. Stone-age people probably used wood waste to fuel fire since greenwood is very difficult to burn. Manufacture of items from wood also began very early. Wood was used for tools and weapons and, no doubt, cut-offs from the production of long implements were used for short axe-handles or pegs, while chips and shavings served for fire kindling.

This paper focuses on non-fuel uses of wood wastes. However, the reader must remember that by far the most important use of wood wastes in large areas of the world is as fuel. This aspect of the use of wood wastes is covered in a separate paper, "Understanding the Use of Wood Wastes as Fuel." (*) Widely used directly as domestic fuel, as kindling, and as the raw material for charcoal.

People throughout the developing world, both urban and rural, consume fuel wood and charcoal faster than it can be renewed. Meanwhile, an insatiable demand for paper made from woodpulp, wooden building components, furniture, and other goods also contributes to deforestation. Economical use of wood wastes instead of new wood helps to preserve forest and woodland in developed countries and is becoming essential to the survival of the poor in many parts of the Third World, as fuel becomes more scarce.

Understanding Wood Wastes As Fuel - 1986-01-01

This paper describes a number of uses of wood wastes as fuel, which is how the greatest proportion of wood wastes are used. Non-fuel uses of wood wastes, for example in building materials, industry, and agriculture, are described in another paper, "Understanding the Non-fuel Uses of Wood Wastes." The issue is acute, because the poor throughout the world, both urban and rural, continue to consume fuelwood and charcoal faster than it can be renewed. Meanwhile, an insatiable demand for paper made from wood pulp, wooden building components, furniture, and other goods also contributes to deforestation. Economical use of wood wastes instead of new wood helps to preserve forests and woodland in developed countries and is becoming essential to survival of the poor in many parts of the Third World, as fuel becomes more scarce.

Understanding Ethanol Fuel Production And Use - 1984-01-01

This paper describes the production and use of ethanol (ethyl alcohol) as a liquid fuel. The production of ethanol is a well-established technology; however, the use of ethanol as a liquid fuel is a complex subject.

Environmentally Sound Small-Scale Livestock Projects - 1986-01-01

Most animal science manuals have focused on the care and management of common breeds of domestic animals to achieve greater production. This manual emphasizes the environmental factors that affect livestock and livestock interactions. Standard livestock texts should be consulted for detailed management practices. The bibliography lists some of the more comprehensive of these, especially those that are most appropriate for tropical latitudes.

Traditional livestock texts cover the common domesticated animals, such as the cow, sheep, goat, and chicken. This manual also deals with animals that are unique to certain areas. The intent here is to stimulate thinking about possible options and to stress the uniqueness of local environments in tropical areas. In other words, there may be a local but relatively unknown or overlooked animal that has great potential for development as a livestock project.

Many references are made to the goal of developing a farming system that is compatible with the environment. Just as a tree or wild animal is part of a forest, a livestock project is a part of a farming system. A farming system is an organizational structure that interlinks the various activities of farmers and the distribution of resources. Farming systems may be based on one major activity (for example, the growing of coffee for export), but also may include other activities that do not conflict with respect to labor requirements, use of land area, or use of other resources. An integrated farming system is characterized by strong interconnections among various farming activities that serve to conserve resources and labor and to reduce the need for imported feeds and fertilizers.

One goal of livestock management is to increase production per animal, which at the same time increases total production on a given area of land. Although this may be the goal of a project, a broader view places livestock production in juxtaposition with local environments, local agricultural systems, and community traditions.

Thus this manual emphasizes the following key concepts:

* maintenance of environmental balance through recycling, regeneration and knowledge of interactions in natural systems

* active involvement of local people in planning, decision-making, and management

* preference for traditional agricultural techniques that have a sound ecological basis

* integration of livestock, cropping, and other land-use systems

ECHO Library

Environmentally Sound Small-Scale Agricultural Projects - 1990-01-01

This manual is designed to assist those who plan and implement small-scale agricultural projects. By promoting awareness of environmental concerns, the manual can increase the development worker's ability to design projects that are both environmentally sound and potentially more sustainable.

This manual has two objectives:

1. To promote well-planned and environmentally sound small-scale agricultural projects.

2. To introduce environmental concepts into technology development and alternative management techniques, and encourage the transfer into training programs.

Understanding Swine Production - 1985-01-01

Swine production provides red meat for the human diet, uses less feed than is required to produce beef or lamb, and is also a source of bides and cooking fat. Swine are also scavengers, and can make productive use of many materials that would otherwise be wasted.

Pigs (young swine of either sex weighing less than 120 pounds), were domesticated in China as early as 4900 B.C. Biblical writings mention them as early as 1500 B.C., and there are references to the keeping of swine in Great Britain in 800 B.C.

Today, swine are raised throughout the world. Their numbers are particularly high in countries that are heavy producers of corn, barley, and potatoes. Countries that have surplus dairy by-products such as buttermilk and whey also produce many hogs (domesticated swine weighing more than 120 pounds, raised for market). The only places where swine production is not suitable are where religious law (as in Islam and Orthodox Judaism, for example) or strong tradition forbid the consumption of pork. Even in such places, small operations serving special markets are sometimes permitted.

Climate is not generally a limiting factor except where it threatens feed supply. Swine are raised in both warm and temperate climates, although young pigs must be kept warm, and sheltered from weather extremes.

Swine production around the world is extremely varied. Wild pigs are hunted. Single pigs are cared for and fed, to yield food for festivities or for routine family fare. Swine can be produced efficiently in very small numbers for home or family farm use, or in larger numbers for marketing. Large-scale production is more likely to succeed where cooperative marketing is possible.

The technology of swine production is well developed. Feeding, management, housing, health, and marketing systems vary greatly within and between countries. In parts of the world where labor is cheap and capital is scarce, labor intensive systems tend to be used, while production methods in industrialized countries tend to be nore capital intensive. Hogs in some areas are raised primarily on forage, while elsewhere large numbers are produced in total confinement without green feed.

There are many types, breeds, and systems of breeding. Purebreds, hybrids, and crossbreds furnish most of the world's pork supply in various grades or quality. Crossbreeding accounts for about 90 percent of swine production in the United States and Great Britain.

Understanding Multiple Cropping - 1985-01-01

Multiple cropping, simply defined, is the growing of two or more crops on the same field during the same year. When the crops are grown one after another the term "sequential cropping" is applied. If the second or later crops are the result of regrowth of the first crop, then the term "ratoon cropping" is used. Sugar cane (Saccharum spp.), sorghum (Sorghum spp.), and even rice (Oryza sativa L.) can be ratoon cropped. Crops that produce no regrowth, as in the case of most annuals, cannot be ratoon cropped.

When two or more crops are grown simultaneously on the same plot of land the term "intercropping" is appropriate. Such crops may be mixed planted, that is, the plants of different crops are intermingled; or they may be sole (pure stand) planted in alternating rows, that is, the plants of each crop are grown in separate rows or strips (wide rows). When one crop is interplanted with a second crop as the first crop approaches maturity, the practice is termed "relay cropping." All of these cropping practices come under the general heading of multiple cropping.

All forms of multiple cropping have the potential to utilize the soil more efficiently, resulting in greater production from a given unit of land. This is especially true in tropical or subtropical areas of the world with wet and dry seasons. Where water for irrigation is available, exploitation of the abundant solar energy in the dry season is possible. Double, triple, and even quadruple cropping has dramatically increased food production in some countries--making them exporters instead of importers of food crops. Less dramatic increases can also result from other forms of multicropping. Beans (Phaseolus vulgaris L.), for example, can complete their life cycle in dry periods, if fertilized and relay planted in corn or maize (Zea mays L.) toward the end of the wet season.

The exploding world population continues to place a severe strain on existing land resources and their ability to provide enough food. Any technology that can result in increased food production from present land holdings has great potential for easing hunger around the world. Some researchers consider multiple cropping the most important of today's agricultural practices. Both high and low technology societies can profit from greater use of multiple cropping.

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