ECHO Tech Notes are subject-specific publications about topics important to those working in the tropics and subtropics. Our material is authored by ECHO staff and outside writers, all with experience and knowledge of their subject. These documents are free for your use and will hopefully serve a valuable role in your working library of resources in agricultural development!


ECHO Technical Notes are moving to this location. Tech Notes published prior to May 1, 2015 are available as PDF downloads here.

20 Issues in this Publication (Showing 1 - 10)

TN #84 Understanding Salt-Affected Soils - 2016-08-17

Farmers and gardeners in semi-arid and arid regions of the world face two associated but separate problems, which limit the crops they can grow and the yield of these crops. The underlying problem is lack of rainfall needed for growing plants. The second is accumulation of salts in the root zone. The two are interrelated, but do not necessarily occur together.

Plants need a certain amount of soluble salts, but excess salts in the root zone reduces plant growth by altering water uptake. When the salt content of soil water is greater than that of the water inside the plant cells, the plant roots cannot absorb the soil water. They may even lose water to the soil. Excess soil salts can also cause ion-specific toxicities or imbalances. In some cases, the cure for these problems is to simply improve drainage. However, salinity problems are often more complex and require proper soil management as well as use of salt tolerant crops.

What’s Inside:

  • Introduction
  • Formation of salt-affected soils 
  • Soil remediation
  • Soil management 
  • Plant management
  • Measuring soil salinity

TN #76 Charcoal Production in 200-Liter Horizontal Drum Kilns - 2016-02-05

Until recently, firewood was taken for granted in northern Thailand.  With vast forests full of many types of trees, upland households could afford to be choosy concerning the wood they used for cooking.   

However, in recent years, more and more communities are facing restricted access to forest products due to the establishment of national parks.  In many areas, deforestation caused by agricultural activities, such as the encroachment of large plantations, is also resulting in declining access to firewood.

In upland communities, commercial types of cooking fuel like propane are not readily accessible or affordable.  With limited options, communities and development organizations have begun considering alternative fuels.

TN #83 Agriculture Extension with Community-Level Workers: Lessons and Practices from Community Health and Community Animal Health Programs - 2015-11-04

Active learning and exchange of knowledge are key to farmer adoption of beneficial agricultural innovations.  Community health worker (CHW) and community animal health worker (CAHW) programs have led to a rich body of knowledge about extension, much of which is applicable to efforts aimed towards small-scale farmers. Drawn from the literature on these programs, this document captures key lessons and practices relevant to developing, implementing, and sustaining effective community agriculture extension endeavors.  The objective of this paper is to inform and strengthen agricultural extension programs that provide services through community-level workers.

TN #82 SRI, the System of Rice Intensification: Less Can be More - 2015-09-21

The System of Rice Intensification (SRI) is a method of raising rice that produces substantially higher yields with the planting of far fewer seedlings and the use of fewer inputs than either traditional methods (i.e., flooding) or more “modern” methods (using mineral fertilizer or agrochemicals). This approach involves various practices for plant, soil, water and nutrient management. SRI has been successfully used in more than 50 countries and has been promoted extensively by Dr. Norman Uphoff with Cornell University.

TN #81: Introduction to Tropical Root Crops - 2015-02-16

Tropical root and tuber crops are consumed as staples in parts of the tropics and should be considered for their potential to produce impressive yields in small spaces.  They provide valuable options for producing food under challenging growing conditions.  Cassava and taro, for instance, are excellent choices for drought-prone or swampy areas, respectively.   In this document, tropical root crops are compared both to enable people to recognize and appreciate them as well as to familiarize readers with their strengths and weaknesses in different tropical environments. Though tropical root crops initially seem to be very similar in their uses, they exhibit important differences. 

TN #74 Agriculture Components for Small Institutions - 2013-01-01

The ECHO Asia Regional Office receives frequent inquiries from small organizations seeking input and other assistance related to their agricultural initiatives, including questions such as the following:

  • How many acres would it take to grow enough food (other than rice) to feed 38 people year round?
  • What crops are most likely to be grown for that purpose?
  • How would you quantify the amount of labor that such an endeavor would require?

Essentially, many inquirers are asking, “How realistic is it to combine agricultural components into small institutions, and are there any examples of effective efforts?”

This technical document goes through how to approach answers, proposes some potential benificial practice and shares lessons learned.

What’s Inside:

  • An Effective Farm for Children
  • Realistic Expectations at Suan Aden
  • Good Management – Clear Priorities
  • Lessons Learned
  • Agricultural Options for Institutions with Land Constraints
  • Outreach Potential

TN #78 Zai Pit System - 2013-01-01

“Zai” is a term that farmers in northern Burkina Faso use to refer to small planting pits that typically measure 20-30 cm in width, are 10-20 cm deep and spaced 60-80 cm apart.  In the Tahoua region of Niger, the haussa word “tassa” is used. English terms used to decribe zai pits include “planting pockets”, “planting basins”, “micro pits” and “small water harvesting pits.” Seeds are sown into the pits after filling them with one to three handfuls of organic material such as manure, compost, or dry plant biomass. The following quotes provide further detail.

What’s Inside:

  • Introduction
  • Historical background
  • Technical Details
  • How to optimize the zai system
  • Other plant basin systems
  • References

TN #71 Foundations for Farming (FFF) - 2012-01-01

Dawn Berkelaar, working with Dr. Martin Price and Danny Blank, featured this farming system in EDN 98. At that time, the technique was known as “Farming God’s Way” (FGW). Subsequently, the name was changed to “Foundations for Farming” (FFF); however, it continues to also be promoted as FGW. FGW and FFF Internet URL’s, links to much more detail, are given at the conclusion of this section. The article from EDN 98 is summarized here using the name, FFF.

What’s Inside:

  • History and Background
  • Principles
  • Step-by-Step Instructions
  • Success Stories
  • Conclusion

TN #72 Sloping Agricultural Land Technology (SALT) - 2012-01-01

Asia makes up less than one third (30%) of the world’s land area and yet carries over half (56%) of the world’s
population. Moreover, the average population density of Asia becomes a significant long-term problem when food production is considered. Some countries in Asia have a population density of up to eight people per hectare. In addition, the Food and Agriculture Organization (FAO) of the United Nations predicts that the world have to double its food production by the year 2030 to feed its exploding population. However, Asia, when compared to the rest of the world, has very little land that is suitable for cultivation that has not already been exploited.

To compound the problem, much of the land now under cultivation in Asia has been classified as degraded or as having undergone moderate-to-severe erosion. According to FAO, many Asian countries now have 20% or more of their lands considered “degraded,” with some countries approaching 50%.

What’s Inside:

  • The Problem: Deforestation
  • leading to soil erosion
  • Introduction to SALT
  • The Ten Steps of SALT
  • Advantages of SALT Farming
  • Conclusion

TN #69 Tree Gardening - 2011-01-01

Lack of food security is one of the biggest challenges that Central Africans face each day as they toil in their gardens, trying to produce enough food to simply feed their families and afford other expenses in life such as health care or schooling for their children. 

Main factors limiting production include trees, and the lack of means to renew farming supplies. But the fact of the matter is this: how well Central Africans’ gardens do determines how well they will survive.  In order to combat this form of poverty, we have found one major principle Central Africans can practice that we believe will improve their chances of survival—and that is simply to practice “diversity,” both in what they eat and in what they grow.  

Diversity in the diet helps to guarantee enough nutrients from each of the three major food groups of protein, fat and carbohydrate (energy), as well as the vitamins and minerals that are necessary to achieve healthy bodies and strong minds.  

A diverse agricultural system must be established to ensure that the proper foods are available for a family to eat.  Over the decades that we have served here in Central Africa, we have found that a type of agroforestry system known as “tree gardening” has been the most successful way to promote this kind of diversity. Education, via seminars, has been the method for sharing information on this kind of system, along with demonstrations and visits to Gamboula’s Garden of Eden where we have planted over 500 different kinds of fruit and other useful trees and vines.  Eden is also the hub of the agroforestry part of our ministry; the agroforestry staff go out to villages (over 100 villages were visited over a 10 year period prior to the writing of this document in 2011) to train local farmers interested in establishing agroforestry cooperatives and in planting tree gardens.  Our ministries here in Africa have been based on learning new ways to raise nutritious foods from both annual crops and tree crops, and then teaching others about them. 

What’s Inside:

  • Introduction
  • What is Tree Gardening?
  • Establishing a Tree Garden