Amaranth to Zai Holes, Ideas for Growing Food under Difficult Conditions (ECHO, 1996, 397 p.) 1: Basics of agricultural development (introduction...) Background in agricultural development (introduction...) Nature of small-scale tropical agriculture Some common problems Steps toward improving small-scale agriculture Summary Book reviews Selecting suitable tropical crops (introduction...) Technical note: selecting the right crop for your location in the tropics or in the subtropics (introduction...) Introduction Principal factors determining crop potential Prediction of suitable crops Table I. Ecological or life zones of the tropics, sub tropics, and warm temperate zones Table II. Annual crops (or perennial crops grown as annuals) - climatic needs crop : rainfall - temperature - other considerations Table III. Important perennial and tree crops climatic needs Table IV. Suggested crops for specific climatic zones Discussion Appendix I. Maximum ecological amplitudes for some tropical crops Technical note: Comparison charts of tropical crops What seed would you take to an uninhabited tropical island? How can I garden in the hot humid tropics? Resource centers for agricultural development

Amaranth to Zai Holes, Ideas for Growing Food under Difficult Conditions (ECHO, 1996, 397 p.)

1: Basics of agricultural development

There are certain basic and important questions we receive which are so encompassing that we cannot answer them in a personal letter. One such question is, "I have just begun work in this country. My degree is not in agriculture, but I want to help local farmers. They know much more than I do about farming in this area, but there must be some ways to make improvements. Where do I begin?" This chapter gives a framework of theories and ideas on getting started in agricultural development, guidelines for selecting crops and innovations, some resources to assist you in the field, and a model for experimental work in your community.

Background in agricultural development

TECHNICAL NOTE: A GUIDE FOR BEGINNERS IN SMALL-SCALE TROPICAL AGRICULTURE by Dr. Franklin W. Martin, a researcher and consultant on small farming systems in the tropics.

You want to help people in the tropics. Beautiful! The tropics are waiting for you. No matter what your abilities, you can offer your service to others in the tropics. Your concern for the physical and spiritual well- being of people can be translated into fruitful work. Your first asset is your goodwill, your willingness to serve.

As you begin to get acquainted with the tropics, you will find that common problems include the production and use of food. Among the poor, those that most need your help, obtaining one's daily bread is a constant concern. This is not only a question of eating. It is first a matter of production, second of distribution and storage, and third of preparation of meals and balancing of the diet. It is highly probable that when you arrive in the tropics you will not have all the knowledge you need of food production and use in order to help tropical people with their priority needs. It does not matter what experience and training you may have had in your temperate homeland; you cannot be fully prepared in advance. This is normal, and do not let it discourage you. Frequently, however, to accomplish your purposes you will need to help others with their needs to produce and use food better.

The tropics are different from the temperate zones. While in theory it might be possible to produce food crops all year round, in reality a wide range of biological and social factors determine what crops are produced and during which seasons. The soils are formed by different processes than those of the temperate zone. They tend to be acidic and heavy, with low natural fertility; but there are numerous exceptions. Day length is short during part of the year, but never as short as in the temperate zone during the winter. Day lengths are longer 6 months later, but never as long as in the temperate zone during the summer. Many tropical plants are very sensitive to length of day, and flower in response to small differences.

Time and length of the rainy season vary, making some climates very dry while others have regular rains almost all year. The most common weather pattern in the tropics is the monsoon, characterized by drought during short days and rain during long days. Tropical crops are often distinctive from the crops of the temperate zone, but even when they are the same, the varieties are almost always different. The methods of producing them are highly varied, but usually include small-scale techniques. Even the layout of the garden is different, often an irregular and undisciplined mixing of trees and vines with mostly perennial vegetables. Add to these differences those due to local custom, food preferences, and personal preferences and you will quickly understand that the tropics are not like home.

This is a problem only if you make it so. If you try to teach in the tropics the patterns and customs that you are familiar with, you will almost always fail. Therefore, your task will be first to learn the techniques that local people are already using. In so doing your respect, understanding, knowledge and abilities will grow, and you will pave the way towards improvement of the local techniques. It can help you become a small-scale food production expert.

Nature of small-scale tropical agriculture

The scale of agriculture in the tropics ranges from the small household farm to very large farms. Tropical agriculture is usually labor-intensive, seldom machinery-intensive. Large farms, sometimes called plantations, are often concerned with production of crops that can be exported. Large and medium-sized farms are always concerned with sales and making a profit.

On the other hand, small-scale agriculture has a double purpose: subsistence (feeding the family) and marketing (cash or barter). Food which is produced on the subsistence farm is itself a savings in that income need not be expended. However, subsistence is more than just a way of life. It is often the only alternative that a family has. The food produced on the small farm is often not just a financial matter, but also a matter of life or death. This is the reason that some small farmers seem to follow traditions rigidly and resist change. The price of a mistake may be too high.

The crops grown on the small tropical farm are usually basic subsistence crops: grains, legumes, roots and tubers. These crops often are the best crops to grow to sell, for they are the crops used in great amounts by others. Often very little attention is paid to fruits and vegetables. Fruits are often neglected because they are so abundantly produced, at least during their season, that they are available to most and surpluses are difficult to sell. Their value in the diet, chiefly in terms of vitamins but sometimes carbohydrates and oils, is seldom appreciated. Vegetables, as known in the temperate zone, are produced even less than fruits, but there are many exceptions to this rule. European vegetables are often unadapted, but can be produced in the highlands, during the cool season, or when varieties adapted to heat or other specific conditions are available.

There are many tropical vegetables that are seldom if ever seen in the temperate zone. Newcomers to the tropics do not recognize them and may wrongly assume that the local people do not grow vegetables. Many of these are the young and tender leaves of shrubs and trees. Some are wild but protected, and others are conscientiously planted. Any one of them is likely to be many times more nutritious than civilized lettuce. Some tropical vegetables have many edible parts including young leaves, shoot tips, flowers, tender pods, immature seeds, dried seeds, and roots or tubers. People often know these other uses of local vegetables, while they may be unaware of many uses of introduced plants.

When starting out, experimentation with very obscure tropical plants is not advisable. The properties of most plants that have a great deal of potential for the small farm are known and described somewhere (though often in hard-to-find publications). The first place to start is always by learning from local people. Then you may also look for plants which may be unknown in your location, but are important in other parts of the world. You can learn about many of these plants through ECHO Development Notes, and seeds for many of them are available from ECHO's seedbank. But remember, learning from local people is always the best way to start.

Small-scale tropical agriculture is also characterized by small amounts of available resources, especially purchased inputs. While labor tends to be abundant, it might be committed to other tasks. Purchased fertilizer or pesticides might be out of the reach of the small farmer. Some small farmers may lack even the most elementary hand tools. Techniques you introduce should ideally be capable of reaching the people with few resources, and yet afford opportunity to those who can take advantage of more advanced technology.

It is appropriate here to discuss what some consider a resource: credit. Indeed, there are many places where agriculture is deemed impossible without credit. As a general rule, the larger the farm, the more easily credit can be obtained. Yet, credit implies an obligation. Farmers, small or large, assume an obligation every time they accept credit. The obligation is hard and absolute, while the ability to pay is soft and full of risks. Small farmers are usually better off when they do not resort to borrowing. Without borrowing the farming risk is the same, or less, and the profit is the same or greater. You must decide whether credit is a resource or liability.

Tropical agriculture on a small scale is an adaptation. In many respects it is the result of an evolutionary process, the growth and change of small farmers in response to the physical and social environments they face. Change is a never-ending process. Agriculture may need to change rapidly sometimes, or not at all at other times. The techniques of small-scale agriculture should not be considered primitive, but as adaptations to reality. They should not be considered sacred and unchangeable either, because change is inevitable. Change represents opportunity: for innovation, for experimentation, for winning cooperation, and for bettering life physically and spiritually.

Finally, small-scale tropical agriculture represents an integration. In the sense used here, integration is the use of one resource to stimulate the production of an "unrelated" output. As simple examples, integration might be the use of crop residues to increase animal production, and the use of manures to increase crop production. Integration is a way of maximizing outputs (food for the family, farm products for sale, etc.) and minimizing inputs (purchase, labor). Integration on small tropical farms is often lacking even when possible. Integrating is one of the easiest ways to contribute to the welfare of the farm family, and may cost no more than some thought and discussion or demonstration.

Some ideas for integrating activities include:

1. Use of moveable cages where animals might feed on and destroy weeds, scratch the soil, and deposit manure in garden areas. This can be done with moveable cages on tethers.

2. Restraining chickens from household gardens.

3. Use of crop residues as litter in animal cages, and subsequent use as compost.

4. Weed control with mulches that are later incorporated into the soil as compost.

5. Off-season green manuring with appropriate species.

6. Disposal of human waste in deep pits, later planted to trees.

7. Use of crop residues as fuel, as building material (roofing, etc.), and as clothes.

8. Use of animal furs or skins as clothes and shoes.

9. Location of small animal cages and outbuildings under fruit trees.

10.Use of ashes as fertilizer and in soap making.

11.Use of trees with edible products as fence posts. Rat control with poisonous seeds of fence trees (Gliricidia sepium).

12.Uses of crop plants for a variety of compatible uses.

13.Location of farming facilities to permit labor saving.

14.Planting crops taking into account the amount of family labor that will be available later.

In most cases farmers have integrated many aspects of their operations. However, on almost all farms there are still opportunities to be discovered. Integration cannot be practiced until all elements of the farmers' systems are understood!

Some common problems

Water. Water is almost always a problem with small-scale agriculture in the tropics. The availability of water will determine what crops can be grown and at what seasons. However, availability of water to the plant is conditioned by many factors, especially the nature and treatment of the soil. Water management is complex, and therefore only generalities can be given in this publication.

Excess water can damage crops by flooding (excluding oxygen from the soil), loosening roots followed by lodging (falling over) of plants, leaching away nutrients, eroding soil, stimulating weed growth, and making work in the fields difficult. The first solution to excess water is to reduce its effects by providing better systems of drainage (ditches, furrows, or planting mounds).

Lack of water is a constant problem. One solution is to use irrigation. If this cannot be done, loss of water is partially controlled by plowing, terracing, use of pits to capture runoff, mulching, incorporating organic material in the soil, etc. Drought requires the use of appropriate crops (millet is more drought resistant than sorghum; sorghum more than corn). Some crops have drought-resistant varieties. Some soils retain water so well that certain crops can be planted and grown to maturity after rain ceases, without addition of more water. You can expect that small farms will need water management systems to maximize production.

Weeds. Weeds are a major problem on every tropical farm, large or small. As living plants they compete with crop plants for space, light, water and nutrients, and thus reduce yield. Furthermore, they usually produce their seeds before cultivated crops do, and thus assure their future. Seeds of many species live for years in the ground, and cultivation to destroy existing weeds brings previously buried seeds to the surface where they can germinate. Weed control is a major subject. A brief guide to weed control has been printed by ECHO and is available by request.

The major goal of weed control is to reduce the competition with cultivated crops. The elimination of weeds from a field is impossible. Often when one pesky species is controlled, another arises to fill its niche. Practical control is achieved through one or a combination of methods, which might include reduction of germination, reducing the growth rate, or killing the weed during its growth.

It is almost always possible to improve weed control on the small farm. Better weed control will almost always improve yields. Yet, you should be aware that weeds can be tolerated in some situations. It may be uneconomical to control them, especially if they are few in number, not very competitive, or only present as the crop is maturing. A good rule for the time of control is as early as possible.

Soil Fertility. Problems with the fertility of the soil almost always occur on the small tropical farm. Only on those farms of exceedingly rich soil where primary or secondary forest has been cut does one occasionally find fertility that cannot be improved. Soil fertility problems vary in terms of nutrients that are lacking. A soil analysis may be helpful, but is often not adequate. It will not measure other equally important factors such as the availability of nutrients that are present (this is determined in part by the form in which they are held), or the texture of the soil. It appears that the field is very complicated, and it is! The best analysis of the soil may be a small-scale trial of its ability to support crops.

Nevertheless, some very important generalities can be made. No matter what the nutrient problem of the soil, improvement can be made by the addition to the soil of organic material (any refuse from dead plants and animals). This material is best if first composted (rotted by fermentation, producing heat). This is feasible in the home garden, but may not be feasible on the farm. Useful results can be obtained when the organic material is mixed into the soil, or even when it is applied as a deep layer on top of the soil. For best results large amounts are needed. It is difficult to apply too much. The most useful organic material is animal manure. Crop refuse often contains abundant carbon, but little nitrogen. Applying some nitrogen in the form of manure or as chemical fertilizer is desirable. Growing of a crop that can later serve as organic material (green manure crop) is often good practice. The best of such crops are legumes, including the vigorous velvet bean and lablab bean.

Where sufficient organic material is not available, mineral fertilizer will almost always improve yields. When no guidelines are available, equal parts of nitrogen, phosphorus, and potassium can be used. The first 100 kg/hectare gives the most dramatic response. Since crop growth may be limited by factors other than fertility, very high rates (e.g. 1000 kg/hectare) are seldom economical on the small farm. Too much mineral fertilizer, especially nitrogen, may even reduce crop yields. It will result in crops that are too soft, have few roots or tubers, or are susceptible to drought.

Appropriate Species and Varieties. Newcomers in a rural area often try to help local people by quickly introducing something that they know to be useful through their previous experience elsewhere. This is such a common error that each would-be reformer or teacher must be on guard for this mistake. Techniques developed elsewhere often do not work out when transferred to another area. New crops are often ill-adapted or not culturally accepted. New varieties of an acceptable crop may fail for numerous reasons. Nevertheless, often the introduction of a better variety of an already commonly used crop will dramatically improve the welfare of the people. It is appropriate to look for innovations. Just remember that all innovations must be carefully tested in the immediate area.

The testing of a new variety can be very complicated or very simple. The simplest approach is to grow the new variety alongside the old, using the same techniques for both, and to harvest, eat, sell, and store both with the farmer, who will rapidly discover which is better. A more advanced approach is to become familiar with what other agencies are testing or developing, and test these materials first.

An even more complicated task is to describe the deficiencies of the existing varieties with the production systems, and to seek the advice of an expert. Often a newcomer will see a problem without understanding it. Low yields, for example, can be caused by a large number of factors. Very high yields are utopian, and may be achievable only when all growing conditions are maximized or all limiting factors are controlled. You may never achieve the maximum, but with improved techniques and better varieties, you should be able to improve yields. What should you do? Proceed cautiously. Find out what has been attempted. Find the rationale behind existing varieties and techniques, and then proceed with caution. Look for new crop varieties first from the agricultural experiment stations and departments of agriculture in the region or country, and from your colleagues in similar situations.

Finally, crop adaptation is often very location- and technique-specific. Changes of area and of technique may change the variety desired. There is no end to the development of new techniques or the testing of new varieties. Don't expect to reach perfection, but strive for improvement.

Pests and Diseases. Every crop plant has its pests and diseases. While the crops, their pests, and diseases may be different in the tropics, the principles of control are about the same. These are mentioned in ECHO's document "Control of Weeds, Insects and Diseases on the Small Farm or Home Garden." Pests and diseases may limit the production of a given crop in a particular region. When resistant varieties are available, their use is usually the most satisfactory and least expensive control. However, resistance cannot be obtained for many crops.

The use of chemical controls has many disadvantages: danger to the user and to others, possible contamination of the farm, killing of beneficial insects, and increased costs. Very often partial control can be achieved by changes in the method of production or cultural practices. Usually farmers know something about these conditions, but may not have developed an integrated approach in which all knowledge available is incorporated into the system of control. There is great opportunity for progress on the small tropical farm through control of diseases and pests. Quite often the disease or pest problem occurs after harvest; thus special knowledge of appropriate harvesting and post-harvesting practices is important.

Interaction of Agriculture and Human Welfare. Agriculture on the small tropical farm is intimately related to the health of the farm families. Both ignorance and custom, as well as lack of food or facilities, may interact with farming plans, food produced and methods of use. A knowledge of good nutrition and good hygiene is desirable if farm families are to be helped. A newcomer who chooses to accept local customs uncritically may literally die. By example and by teaching, families can be taught the basics of nutrition and hygiene.

Nutrition. Farm families often fall far short of eating balanced diets of the four basic food groups (meats and eggs, milk and milk products, breadstuffs, and vegetables and fruits). In the third world, three kinds of malnutrition are evident, often combined: protein, carbohydrate, and vitamin and mineral. Ample information is available in this field and often is printed in the local language and is related to local custom. Publications are usually available from local government agencies.

Attacking only part of the nutritional problem is seldom the solution. An integrated approach is almost always necessary, including growing the right foods, producing animals, and using the foods rightly. Sometimes good nutrition involves introducing foods into the diet that are not customarily used. This is often difficult because people do not change their preferences easily. Sometimes the new food can be incorporated into traditional dishes. Sometimes acceptance begins first with the children.

Some of the crops or foods with great nutritional promise are high-lysine corn (also called hard endosperm opaque-2 corn) which is useful for its balanced amino acids, leaves of many kinds for vitamins A and C, new legumes for protein (including white in place of colored beans), soybeans for soybean milk, seeds of heavy- seeding squashes and their relatives for protein and edible oil.

On the other hand, rural peoples of the third world often eat more than enough starches, and thus might consume too many calories in relation to oil, protein, vitamins, and minerals. This is often because such foods are readily available. These people may need to adopt new dietary habits for a healthier diet.

Hygiene. The life span of rural people is often shortened due to poor hygiene. Dehydration of babies due to diarrhea is a major problem in the third world. Some of the basic problems in hygiene are the following: Pigs and chickens distribute their excrement throughout the yard, and thus parasites and intestinal infections are common. Personal hygiene (use of toilet or latrine, bathing, washing before eating) may be difficult, impossible, or neglected. Proper precautions may not be used for preparation, storage, or consumption of food. Water for drinking and bathing may be contaminated. Disease-bearing pests may be present.

In advanced countries, the normal practices followed for good hygiene are so common that their essential nature is overlooked. It is dangerous to assume that rural conditions are equally valid alternatives. Good hygiene is always desirable and often will make a life-or-death difference.

Family Economy. Farm families, like many others, need money. The lack of money often leads to poor nutrition. A pig on a small farm may be saved to sell when there is great need. The eggs are collected not to eat, but to sell. Crops are grown which have a market, not for their nutritional contributions.

A good farming system integrates crop production (food, feed, fuel), animal production, and making money, with preserving and improving health. (Growing vegetables for a cash crop can sometimes increase on-farm vegetable consumption because there are so many nutritious but not marketable culls.)

Steps toward improving small-scale agriculture

As with many good things in life, improvement of small-scale agriculture is not easy. Since every region (and indeed every farm) is distinctive, there are no automatic solutions to the improvement of agriculture. Nevertheless, from the experience of many persons, a few principles can be instilled as follows:

Literature. Agriculture requires information. Follow this document with other publications that teach principles. Be sure to obtain a subscription to ECHO Development Notes (free for those who work overseas with small farmers) and your own copy of this book, plus back issues after EDN 51. Enrich your library with publications of the country or region in which you will serve. Be cautious with information developed for other regions or countries with different soils, climates, and social-economic conditions. Do not believe that miracle solutions can be found or that any publication will solve your problems. Information is like a set of tools to be used judiciously.

Diagnosis. The first step in improving rural agriculture is to ask the right questions so as to arrive at a diagnosis. These may include the following, and others: What land is available, and what are its limitations? What crops are grown, during what seasons, with what techniques, and with what results? How are the crops harvested, stored, transported, and used? What crop residues remain, and what is done with them? What animals are produced on the farm, using what techniques? What is done with the animals and their by-products? What do people eat? How is food prepared and stored? What parts of the diet are inadequate? How does this change with time of year? How does animal production interact with human welfare? What do people buy, trade or share? Where do they get the money? What markets exist for new products? What purchased inputs are available (tools, mineral fertilizers, fungicides, etc.)? What is the health of the people? What are the social and economic factors influencing distribution and marketing? What is the infant mortality rate and the life expectancy? Does the diet appear balanced? From what diseases do people suffer? As answers are compiled, you will form an impression of the fundamental problems in the community. In addition to general problems faced by everyone, there will be idiosyncratic problems belonging to specific families or persons. Some decisions will need to be made about the most important problems to be attacked as well as their root causes. The fundamental problems may not be agricultural.

Selection of Alternatives. From this point, the discussion will concern only agriculture, the theme of this article. While other problems are too numerous and complex to be discussed here, they merit equal or perhaps greater concern.

From the diagnosis of the agricultural situation, plan several alternatives. The closer the alternatives are to current practices, the more likely they will succeed. Select rational alternatives, based on knowledge and previous experience if possible. They may have experimental aspects (in the sense that one can never be sure of the results). By organizing alternatives that address real problems as the people perceive them, chances for success are enhanced. Some of the alternatives may be...

A new crop, a new variety
An improved system of soil preparation
A different season of planting
A changed physical arrangement of the plants
A better way of fertilizing
A better nursery (if the crops are transplanted)
A new way to control weeds or pests
Improved harvest or storage
Better ways of food preparation
New uses of crop residues

Similarly, additional alternatives may be sought for the animal component of the farm.

Testing Alternatives. Try selected alternatives first in plantings completely managed by the innovator. These plantings could be in schools, churches, backyard gardens or rented fields. Test alternatives alongside plantings which use the farmers' technology. As soon as possible, involve farmers in testing alternatives alongside their own plantings. The same principles are applicable if the alternatives include storage or cooking techniques or any other aspect of production and use of food. Trials should be made for comparisons before new technology is introduced to farmers or cooks. If the alternatives require new markets or marketing techniques, these should also be worked out before the alternatives are presented to farmers.

In normal practice, a foreign innovator is closely watched. It is a serious error to introduce a technology that is not a significant improvement. (However, you should expect some disappointing results along with successes on your personal trial plots!) On the other hand, successful aspects of a technology (successful alternatives) will be watched and tried by others.

Verification in Farmers' Situations. Even when new alternatives have been demonstrated to be successful they must be verified in the hands of the farmers. Farmers will put them into use in their own way and will find strengths and weaknesses not obvious to the innovators. These verification trials allow farmers to adapt and adopt innovations useful for them. A grassroots approach is the most useful in the spreading of innovations; but as acceptance becomes generalized, new doors may be opened for more formal training in agriculture, food processing, nutrition, and hygiene.

Relating to Local People. While learning about a new culture it is not necessary and may, in fact, be undesirable to practice wholehearted local rural ways. You may wish to dress, eat, and balance the diet, practice hygiene, and comfort yourself in your own way. But, private and personal practices which are so important to you may not be appropriate for the people around you. The virtues of tolerance, understanding, and appreciation ought to be your guidelines at every step of the way. You will undoubtedly find that those you work with are loveable and will love you.

Summary

The Best Ways To Help A Small Farm: Become acquainted with what people do, diagnose first, select alternatives, try them out in small experiments-first under your control and then progressively with farmers. Promote that which proves to be better. Never give up, because improvement is always possible.

THE CHALLENGE OF AGRICULTURAL MISSIONS: Notes from ECHO's staff. Doing agricultural missions is not an easy task. Many mission agencies with projects in evangelism, health, education, water, sanitation etc. hesitate to add agricultural projects to their program. Why? Because it is often much less clear what they should do to have a major impact in agriculture than it is in these other areas. It has been said that if you can provide clean drinking water and build latrines you take care of up to 80% of a village's health problems. Likewise, medicines already exist to treat most of the diseases in the developing world. But, if a community is "sick" due to the poverty of farmers, it is much less clear what should be done.

Requirements for a satisfactory agricultural project include the following: It must involve only minimal risk to local farmers who are already living on the edge. It must be something they are not already doing. The plants or innovations should be suited for local conditions, culturally appropriate, and address a felt need among the people. It should not exceed realistic labor and time investments for the users. It should make such a major difference that farmers will readily adapt the innovation on their own. And, it must have a ready market (or be liked as food locally) if it involves sale of a product.

It is almost impossible to meet all of these criteria and some projects have failed miserably. But, there have been successes and well-prepared agricultural missionaries are still needed. Below are a few ideas to keep in mind for designing a successful agricultural project. The list is not all-inclusive, but these are points that come up over and over again.

Be committed to the people and the work. Effective change takes time. Get to know the people and understand their needs. Live with them, learn their language and culture. Earn the right to help them. Cultivate your powers of observation; keep your eyes open. Go as a learner, see why people do things the way they do (most things are done for a reason, even if it seems foolish to you at first). Practice humility and listening. Admit when you are wrong, and expect good ideas to come from local counterparts. Be flexible, as you may become involved in more than you expected. You may find yourself involved in agriculture, regardless of your background in food production or skills and responsibilities in other areas.

Nationals, the people from the communities, must own the project. If they are not involved in every aspect from start to finish, your work will not effect lasting improvements. Use local resources and technologies which are appropriate. Do not do for the farmers what they can do for themselves. As far as possible, they should provide the labor and materials needed. Teach folks to teach others and do not make yourself indispensable. You will not be there forever. All this helps people keep their dignity, avoid dependency, and assure sustainability. Whenever possible work with the government and leadership, not against it.

Identify a few important technologies and test them. There are a lot of technologies which have already been proven in a particular setting. These are well worth a trial in similar circumstances, but nearly everything will require some adaptations to the local situation. A good approach might be to start by promoting a good idea from one area of the country or world in a new area, and work with it until it is recognized as an improvement. Be patient. We visited missionary Bob Ekblad in Honduras who rented the worst piece of land on a very visible hillside along a well-travelled road. People thought he was crazy to try to farm such poor, steep land, but after watching the contour ditches and other soil improvement processes work effectively, they adapted and adopted these practices and soon enjoyed reduced soil erosion and much-improved yields. Even some abandoned fields were brought back into production.

Sometimes you may be called upon to develop a new technology from scratch. If so, be prepared and committed to adapting and promoting the idea over the long term. Joshua Tsujimoto, who developed a raised bed mini-greenhouse system for out-of-season vegetable production in Bangladesh, tells how farmers laughed at him and suggested that they would benefit more if he were sent home and his missionary support divided among the people. But after many years of trials and errors, he developed a very workable system for people to produce vegetables in the rainy season when no one else can, thus greatly increasing their incomes. Persevere.

Expect frustration. We once read that a farmer in the Philippines was able to multiply his cash income 15 times by planting disease-resistant tomatoes. But he declined to plant them again because of social pressures from his less successful family and neighbors. Resist the temptation to become cynical or overly critical when reactions to your efforts are not as you had hoped. We have also heard over and over of plants which succeed brilliantly in one area or season but fail miserably in another. Anticipate such problems.

Start small and be an experimenter. Identify naturally innovative farmers in your area and work with them. Do not be overeager to convince many farmers to implement ideas you have not tried personally or locally; in doing so, you may inadvertently do more damage than good and lose respect in the community. Keep things simple. Truly good ideas will often spread themselves without elaborate promotion.

ECHO's role is to help you find technical ideas to try. You must evaluate which innovations hold potential for your area, and weigh the risks and benefits of introducing these ideas in your community. This book will not teach you the process of community development; it is meant as a resource for people seeking ideas with potential to improve the life of small farming families. But this process of development is essential, and we encourage you to consider the social, cultural, and spiritual aspects of your work alongside the technical part. A few books which deal with the development process are highlighted below.

Book reviews

TWO EARS OF CORN AND OTHER WORLD NEIGHBORS MATERIALS. We have had countless occasions to recommend Two Ears of Corn: A Guide to People-Centered Agricultural Improvement (250 pp.) by Roland Bunch since it was published in 1982. Those of you with minimal experience and reading in the area of community development could find it revolutionary. The rest will find it helpful, as well as a good introduction for those coming to work with you. If you have not read a book such as this I would put it in the must read category. The needs around you are too great to ignore them just because you are not an "expert." But there is great wisdom in learning what you can before moving ahead. We arranged for a copy to be sent to John Douglas in Zambia after he asked our comments on some interesting agricultural projects that he was beginning. He wrote back, "I don't think I have ever read anything that had such a practical grasp of both village problems and solutions. I can already see that the book will make a difference in the way we carry out our program."

The book is divided into 5 sections: (1) General orientation (2) Getting started (3) Choosing and using technology (4) Administration and (5) Expansion and Consolidation. Here are some selected chapter headings: The program goals; the program area; planning; start slowly, start small; limit the technology; choosing an appropriate technology; small-scale experimentation; teaching the technology; employees; supporting services; evaluation and phase-out; multiplying our efforts; building institutions; integrated programs. I especially appreciated the chapter on small-scale experimentation because this is at the heart of much that ECHO does. The author shows that it is possible to find new and better methods or resources with your own experiments and by involving the farmers in experimentation.

You can order the book in English, French, or Spanish for $7.95 each plus $7.50 airmail postage from World Neighbors, 4127 NW 122 St., Oklahoma City, OK 73120-8869, USA; phone 800/242-6387 or 405/752-9700; fax 405/752-9393. Orders for 10 or more receive a 20% discount. Other organizations have also translated it into Indonesian, Vietnamese, and Portuguese; while these languages cannot be ordered from World Neighbors, they can give you the addresses to contact.

World Neighbors also has an excellent catalogue of filmstrips, videos, and printed materials designed to be easily understood by village audiences. The materials are practical and relevant for communities, and can be used for training extension workers. Many of the filmstrips are available in English, French, Spanish, Portuguese, and Hindi. Topics include specific areas in community development, health and nutrition, family planning, small animal raising, and agriculture, trees, and soil conservation. A few filmstrip titles from the latter category are "Planting cultivated pastures," "Fodder trees," "In-row tillage," "New dryland farming technology," "How to take soil samples," "Using the A-frame," "Quinua: protein for the highlands," "Growing mushrooms in tropical climates," and "The use of velvet bean to improve cropping land." A few projectors and accessories are available through them as well. Order the catalog from the above address.

PEOPLE IN RURAL DEVELOPMENT (228 pp.) by Peter Batchelor, veteran agricultural missionary in Africa, is an excellent, thoughtful book on Christ-centered agricultural development. Chapter titles include: People First, Getting Started, The Church and the Rural Poor, Good Stewards, Classroom and Fields, On the Job Training, Health the Key, An Appropriate Response, Whole Families, Workers, Ownership, Working Together, and God and Development. Contact the Paternoster Press/STL, P.O. Box 300, Kingstown Broadway, Carlisle, Cumbria CA3 0QS, UK; fax 0228 51 49 49.

PARTNERS WITH THE POOR (158 pp.) by Jerry Aaker is subtitled "An emerging approach to Relief and Development." The author writes a personal journey through 25 years of international service with church agencies, tracing different trends in assistance, education, relief, and transformation. It is a fine resource for those who wish to examine different theories and issues in development. Order from Friendship Press, P.O. Box 37844, Cincinnati, OH 45222-0844, USA ($12.95).

SOYBEANS AND THE KINGDOM OF GOD: AN APPROACH TO HOLISTIC MISSION (159 pp.) by Sharon Soper recounts her work with developing and promoting soybean flour while serving as a nurse in Bolivia. She discusses how holistic theology of God's kingdom, culture change, and value differences related to the technology of introducing soybeans into the diet. Available from Evangelical Mennonite Mission Conference, Box 52059, Niakwa P.O., Winnipeg, MB, CANADA R2M 5P9; fax (204) 256-7384; Cnd$13 in Canada, US$11 in USA, and US$13 International, postage included.

"COMMUNITY DEVELOPMENT AND CHRISTIAN DISCIPLESHIP: The Wedding of the Great Commandment and the Great Commission" by Gary Hipp offers a brief introduction to an effective relationship of Christian faith and works in a development situation. Contact Mission: Moving Mountains, P.O. Box 1168, Burnsville, MN 55337-1168, USA.

Selecting suitable tropical crops

THE MOST-ASKED QUESTION. What question do we receive the most frequently from ECHO's network? Easily it is some variation of, "What crops can people consider for the region where I work?" This is usually followed by some description of climate, soils, etc. Often some especially difficult condition is outlined-too much or too little rain, farms that are too small, steep, rocky, hot, infertile, swampy, or remote.

This is also one of the most frustrating questions to try to answer. We asked Dr. Frank Martin to put together something that would help you answer the question for yourself. He found it the most difficult assignment we have given him. "It should be possible to characterize soil and climate so that areas that are similar, even though widely scattered, could use the same technology. In practice this has proven very difficult." He knows of two large projects which tried to accomplish this, but neither turned up anything that appears to be useful. "The old- fashioned technique of a variety trial is still the best method to determine the value of a particular crop for your region."

The article that follows contains three levels of complexity. In one table, the most complex, he pulls together 140 crops, including both annuals and perennials, and vegetable, field and fruit crops. It will be useful as a rough screen to chose or eliminate crops you might consider. Other tables list several plants based only on rainfall amount and distribution and on temperature. No attempt was made to prepare an exhaustive list. For each of these climates, he has chosen several useful and probably familiar plants that would be well worth a try.

Technical note: selecting the right crop for your location in the tropics or in the subtropics

by Dr. Franklin W. Martin

Introduction

"What crops can I grow?" Consultants in tropical agriculture often receive letters from Peace Corps volunteers, teachers, missionaries, students, and those who have followed their careers to the tropics, with the question, "What crops can I grow?" Leaders and literate farmers often look for new alternatives to basic crops that do not bring in the income desired and write, "What other crops can I grow?" Conscientious persons from the developing world, and even from academic institutions in the United States ask the same question. Choosing the right crop or crops for a particular place is a common problem, and the information necessary for answering the question is not widely available or easily found. Knowledge of agriculture tends to accumulate in regional pockets that represent ecological zones. While the majority of those that write may understand their own area quite well, they are much less familiar with the broader situation or the whole of the tropics and subtropics.

Improvement of Local Agriculture. Quantity and quality of agricultural produce, and usually the diversity as well, can always be improved. However, it is a mistake to assume in any situation that improvements are easy. Agricultural systems represent biological, socio- economic, and technical evolutionary adaptations to particular ecological systems. Agricultural systems are followed because they work under the local circumstances, or at least they work better than easily visualized alternatives.

It is sometimes relatively simple to improve the technology of third world agriculture, yet investigators are often puzzled why the technology is not readily adopted by farmers. Usually the answer is in the socio-economic aspects of the system, which are frequently overlooked. In highly technical systems, yields and quality might already be high. Improving such agriculture is like shooting at a moving target, hard to achieve a hit.

Traditional approaches to answering the question. The most obvious and useful technique to answering the question, "What crops can be grown?" is to observe and talk with local farmers. They are wealthy in appropriate technology with deep and sometimes almost poetic understanding of their particular crops and production systems. Following farmers' techniques, especially those of farmer-leaders or farmer-innovators, one is practically assured of a crop. Yet, farmers have their roots in tradition. Even excellent farmers may be unaware of what farmers do in an adjacent valley or region. They may not know of improved varieties or technological advances. They will seldom be aware of the world situation, or at times even the local market, and how it affects their crops. Thus, the expertise of farmers is valuable but limited.

A second source of information is that of agricultural statistics. While few countries have as extensive a system as that found in the United States, all countries maintain some records of production, and these clearly show what crops are grown, and usually what acreage and what yield. If a crop is already grown in substantial quantity in a region, then you can be sure it is a crop that not only can be grown, but that can also make money-and that it can be improved.

A third technique is to talk to the local agricultural agent, or, if possible, the nearest agricultural extension office or experiment station. The structure of the system developed to help local agriculture varies, but these people have some knowledge of the crops of the region. They will know which crops the government emphasizes (usually the money makers) and often the improved varieties and technology. Do not underrate them and their potential answers to your queries. While the above traditional sources of information may not be adequate, it would be foolish to start any serious long-term endeavor without consulting these sources.

A fourth technique is to observe the wild plants on the land as an indication of what crops can be successfully produced. This technique has not been developed to the extent that it would be a useful tool, and has as a disadvantage the requirement of special knowledge of the flora. Furthermore, in some regions the original native flora has been destroyed.

An integrated approach. This kind of approach tries to use local, national, and internationally available information to answer the question. The ecological situation is emphasized here. If one can learn to distinguish ecological zones and learns the ecological requirements and preferences of crops of the world, then one can match crops with zones with a high degree of confidence that a given crop can be grown in a given locality. But, even so, always remember that there are other questions to be asked.

Principal factors determining crop potential

The principal factors that determine crop potential are both internal (genetic) and external (environment). Not only do species of plants vary with respect to their genetic potentials and responses to environment, but even within a given species different varieties or different individuals are distinct in adaptation.

Availability of water. Water occurs everywhere, including in the driest desert. Nevertheless, not all water is available for plant growth. For example, water in the air is not available to most plants. Since almost all crop plants grow in the soil, water availability for practical purposes is the water available to plants in the soil. When excess water falls on the soil, a part may run off even before it can enter, and part of that which enters will be held in the soil by physical and chemical forces. In dry climates runoff can be reduced by contour planting, by furrows oriented crosswise to rain-carrying winds, by plowing, and other treatments on the soil surface. Plants can also be planted at the bottom of furrows or in pits to increase their chance to obtain water. The remainder of the water will move deeper into the soil attracted by gravity until it comes to rest on an impenetrable basin or joins an underground stream or aquifer.

Water is lost from the soil not only by percolation downward but also by evaporation on the surface. The rate of evaporation depends on the water-holding capacity of the soil, and also on environmental conditions, chiefly temperature, relative humidity, and wind. In general, sandy soils hold the least available moisture, clay soils and soils of high organic matter hold the most. The water-holding capacity of the soil can be increased, for practical purposes, chiefly by the addition of organic material to the soil. Plants can remove water from the excess flowing through the soil, from basins or aquifers, and from the water that is physically and chemically held in the soil, up to a limit. From a practical standpoint, water availability to a plant is determined also by its ability to retrieve water, with a large and efficient root system. Competing plants (other crops or weeds) also reduce the water available to a particular plant.

Seeds may need water almost continuously in order to germinate, and seedlings may need extra water to grow. The growing plant needs large quantities of water, but may be very adept at getting water because of its root system. The plant that is maturing seeds, fruits or tubers often needs less water. A plant that matures in a short period may avoid drought by its ability to mature when water is available.

Life zones (as defined by Holdridge, see Table I) depend in part on the amount of water received annually. The yearly average rainfall, much more than the extremes, dictates the kinds of woody perennial plants that can be grown without irrigation in a particular zone. The suitability of an annual crop plant for growth in a particular region, however, depends not only on life zone, but also on the water availability through irrigation and through water conservation methods. Distribution of rainfall must also be taken into account in interpreting the life zones. If rainfall occurs over a relatively short period, followed by a dry season, some annual crops might not be able to mature.

Temperature. Temperature affects plant growth directly and indirectly. As temperature increases, chemical activity increases and thus over a certain range, higher temperatures increase growth. However, protoplasm cannot survive excessively hot temperatures. At the other extreme, many plants cannot survive temperatures below freezing. Special organs may be more susceptible to heat (reproductive organs, flowers) or to cold (succulent organs). Some organs, particularly some seeds, may resist both heat and cold. Furthermore, loss of water from plants and soil is increased by high temperatures (as well as by low humidity and wind).

Plants are adapted to particular climates in part by their ability to grow and reproduce at certain temperatures. Among vegetable crops one can distinguish cool season crops (cabbage, lettuce) from hot season crops (corn, squash). Some crops grow best where days are hot and nights are cool (tomato). Life zones as defined by Holdridge depend not only on annual rainfall but also on mean annual temperature.

Altitude and Latitude. Altitude influences temperature and in this way affects plant growth. As altitude increases, temperature decreases. Latitude influences temperature by influencing the amount of light intercepted by a unit area. It also influences daylength. Daylength influences plant growth through hormonal mechanisms which are part of a plants adaptability. For example, short-day plants require or flower best in short days. Long- day plants often flower best only during long days. Some plants are day-neutral and their flowering is not influenced by day length.

Thus, life zones are influenced chiefly by annual rainfall and mean annual temperature. Some of the world's life zones as defined by Holdridge are given in the table. In any region of the earth a person should be able to determine the life zone by weather records. It may now be impossible to do so from the vegetation. Agricultural zones, however, are determined also by availability of irrigation water.

Soil acidity. The acidity of the soil, defined in terms of pH, is a third important factor determining crop potential. While almost all crops grow well in soils with slightly acid pH (6.5), nevertheless crops differ in their tolerance of acidic (low pH) and alkaline (high pH) conditions. The acidity of the soil can be increased with the use of acid forming fertilizers (such as sulphates) and organic materials, or decreased with the addition of lime. These are common agricultural practices. Usually soils of the humid tropics are acid and those of the dry tropics alkaline, but there are exceptions.

Prediction of suitable crops

Use of Table I and the Appendix.

As a first step in determining whether a particular new crop (old crops are obviously suitable) may be suitable for your region, determine the life zone for the region from annual rainfall and temperature. Determine the normal pH of the soil of the region. Consult Table I and the Appendix.

A second step. Classify your environment in a less formal manner than that of Holdridge. First, classify the environment during the period of maximum rains as follows: cool (C), intermediate (IT), or hot (H). Then consult Table II for annual crops and Table III for perennial crops.

Note in Table II that irrigation changes everything. If temperatures are favorable, all vegetables can be grown in a dry climate where water is added. This is probably true of fruits as well. Note also the other considerations in the case of some of the other crops.

Finally, you can use Table IV if your region falls into one of the following categories: hot humid tropics; tropical monsoon; dry tropics; beach climate; wet, cool highlands; and dry, cool lowlands. Consult the portion of the table which corresponds to your climate and find the grains, legumes, vegetables and other crops most likely to be a success.

Table I. Ecological or life zones of the tropics, sub tropics, and warm temperate zones

Table I. Ecological or life zones of the tropics, sub tropics, and warm temperate zones.

T = Tropical
d = dry forest
S = Subtropical
m = moist forest
W = Warm temperate
r = rain forest
C = Cool temperate
t = thorn steppe (if tropical) or woodland (if warm temperate)
B = Boreal
v = very dry forest
w = wet forest
x = desert scrub (if tropical or subtropical) or bush (if temperate)

NOTE: In the Appendix you will see life zone symbols of more than two letters. For example, okra grows in life zones Wdm and Txm. The capital letters refer to tropical, subtropical or warm temperate climates. The small letters are for types of vegetation as determined by the life zones. Using the chart you can see that okra will grow in warm temperate dry forests, warm temperate moist forests, tropical dessert scrub and tropical moist forest climates.

Table II. Annual crops (or perennial crops grown as annuals) - climatic needs crop : rainfall - temperature - other considerations

Table II: . Annual crops: climatic needs

CLIMATIC NEEDS