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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 Các Số trong Ấn phẩm này (Hiển thị vấn đề 127 - 117) |

How To Make Fertilizer - 01-01-1981

This bulletin contains easy-to-follow, well-illustrated directions for making fertilizer with materials likely to be found in a village situation. Included are instructions for making the fertilizer in a simple frame or container, a list of possible raw materials, and a list of general guidelines, including directions for mixing chemical and natural fertilizers.

This bulletin is a basic introduction to composting. It can be used by extension agents, community workers, and others seeking to introduce organic farming methods in areas where such methods are not used. It would be a useful addition to an extension training program.

Understanding Inorganic And Organic Fertilizers - 01-01-1985

Every farmer and gardener realizes that plants receive some of their substance from the soil. Just how much plants depend on soil fertility is not always obvious, however, because so many other factors also influence plant growth--water, sunlight, pests, and plant variety (genetics). In regions of the world where crop yields are extremely high, farmers add large amounts of fertilizer, usually in the form of a commercial product, which they purchase at considerable expense from a farm supply dealer. For example, in the corn belt of the central United States, yields of over 12 metric tons per hectare (200 bushels per acre) may be achieved by using hybrid corn, more than 125 kilograms (kg) of fertilizer per hectare (100 pounds per acre), and sometimes large amounts of irrigation water. Such a farmer may spend $500 per hectare for fertilizer to produce a crop worth $1,500 per hectare.

In much of the world such capital-intensive agriculture is impossible because of its high cost and often would be unwise due to the uncertainty of rainfall, insufficient length of growing season, or possible lack of demand for the crop at harvest. Nevertheless, addition of some fertilizer may be economically justified. The decision as to whether or not to use fertilizer will depend on the answers to the following questions:

  • Will fertilizer substantially improve the yield or quality of the crop?
  • Will the increased value of the crop cover the cost of the fertilizer?
  • Are the risks associated with producing the fertilized crop (lack of rain, short growing seasons, pest damage, unstable market) low enough to justify the investment in fertilizers?

If the answers to all of the above seem to be "yes," then an additional set of questions should be asked:

  • What type of fertilizer is needed, and how much?
  • When and how should it be applied?
  • Will the addition of fertilizer change plant growth in such a way that other problems may develop, like increased susceptibility to drought or pests, collapse of the plants due to stem weakness (called lodging in grain crops), or an undesirable change in quality such as taste, texture, or nutritional value?

Answers to these questions may not be easy to obtain since experience is often essential. Usually the farmer or gardener needs to experiment with fertilizer use in the field in order to learn the advantages or disadvantages. However, fertilizer experiments are often very difficult to interpret due to the many crop growth variables, so that information about experiments by local agricultural research stations may be highly desirable.

Understanding Hydroponics - 01-01-1989

This paper will describe the basic features of a medium- to large-scale hydroponics system and prefabricated greenhouse appropriate for cold climates. Some modifications for a system suitable for hot climates are also discussed. Home gardeners in any climate can use the basic theories contained here, but may want a simpler operation, possibly without a greenhouse or special structure.

Understanding Integrated Pest Management - 01-01-1989

This paper examines the complex nature of pest problems and evaluates both chemical and nonchemical controls. The objectives of IPM are assessed, together with its current accomplishments and its future as a pest-control strategy. Although the paper emphasizes agriculture, the concepts and strategies of IPM can also be applied to forestry, the management of range and pasture land, the control of insects that carry human and animal diseases, and the control of such urban pests as rats and cockroaches.

Understanding Insect Pests And Their Control - 01-01-1985

Insect control is the effort made to protect crops, animals, or other targets of insect attack from unacceptable injury or loss. If destructive insect populations are allowed to cause significant damage or injury to their target host, economic loss or a decline in human health may result.

Destructive insects threaten the value of most food crops both before and after harvest. In addition, insect pests can destroy structures and cause direct injury to animals including humans. However, not all insects are destructive. Some provide direct economic benefit by producing products such as honey or silk; others naturally control harmful insect pests. And of vital importance is the role of insects in pollinating flowering plants.

A population of a destructive pest and its target host (a crop, livestock, etc.) are part of a complex system that includes all other organisms living in a given physical environment or ecosystem. Elements of a natural system, such as a crop, are in a state of balance with one organism affecting the other. Problems occur when the natural balance between destructive and beneficial insects is upset. Corrective action is then required to control the problem or prevent similar pest problems in the future.

Understanding Soil Preparation - 01-01-1984

The purpose of soil preparation is to develop a planting medium that will foster the best possible growth of agricultural crops while preventing the deterioration of the land through erosion, destruction of soil structure, or nutrient loss. The soil preparation system used must be economical, since a large part of the expense in raising a crop occurs before the seed is ever placed in the ground.

OBJECTIVES OF SOIL PREPARATION

The immediate goals to be accomplished in soil preparation are:

  • destruction of weeds,
  • incorporation of organic material,
  • incorporation of fertilizers and lime, and
  • development of the proper seed bed.

Understanding Agricultural Waste Recycling - 01-01-1984

This paper discusses the general theory involved in recycling agricultural wastes and several popular methods. It does not present detailed practical examples. It is important to stress that the choice of recycling method will depend on the type of waste available and on the end use the farmer has in mind for the recycled waste. It is hoped that readers will adapt the general methods discussed in this paper to their own local conditions.

How To Perform An Agricultural Experiment - 01-01-1981

The purpose of this book is to show local farmers and others the basic steps to design, execute, and measure an agricultural experiment. This book does not cover statistical anlysis; it is assumed that trained statisticians are available for this purpose.

Volume III Of Small Farm Grain Storage - 01-01-1980

Small Farm Grain Storage is a set of how-to manuals. Together these volumes provide a comprehensive overview of storage problems and considerations as they relate to the small farmer. The authors recommend the volumes be purchased as a set because the material forms an excellent and complete working and teaching tool for development workers in the field. This grain storage information can be adapted easily to meet on-the-job needs; it has already been used as the basis for a grain storage workshop and seminar in East Africa.

Chris Ahrens' Greenhouse - 01-01-1981

This prefabricated greenhouse can be added to the south side of an existing house for under $225.