|Agro-forestry in the African Humid Tropics (UNU, 1982, 162 pages)|
|Considerations for the future development of agro-forestry|
United Nations Environment Programme, Nairobi, Kenya
Trees are the dominant vegetation in tropical areas, and deforestation leads to a variety of other problems. Deforestation is large/y a result of economic deprivation, for trees are traditionally an integral part of rural life. Agro-forestry provides one solution that is widely applicable. In UNEP's view there are several problems hindering the development of agro-forestry. Among these is the lack of co-operation between those working in different geographical areas and between foresters and agriculturists. However, the greatest need is to collect and disseminate existing research results to field operators. UNEP would also like to see a coordinated programme to develop agro-forestry methods and technologies that are consistent with traditional practices.
Longman and Jenik (1974) have stated that the tropical forest contains the earth's largest biomass, and that its total primary production is greater than that of any other ecological region. In addition to wood fibre, the forest yields fruit, nuts, leaves, flowers, resins, gums, bee products, and drugs, all of which are useful to human beings.
Borlaug 11976) has emphasized that trees are the dominant natural vegetation in most tropical ecosystems and must to a large extent remain so if production from the available land is to be maximized. Only 11 per cent of the land in the tropics is flat enough to be worked with the plough. One-quarter of the land surface is too infertile to produce conventional crops. The remaining area, that forms more than one-half of all land in the tropics, although too dry, too steep, or too rocky to be classified as arable land, is suitable for growing trees and crops interspersed with trees (Bene et al. 1977). The balance in the tropical forest can be irreversibly upset by forest clearance, intensive grazing, or burning.
The problem of deforestation is now recognized by governmeets and international organizations. Some of the problems include rapid siltation of reservoirs, reduction of water supply for human and agricultural use, decrease of electrical power-generating capacity, intensified flooding, loss of badly needed wood products and firewood, loss of valuable plants and animals, and the permanent loss of plant nutrients through leaching.
The largest loss of tropical forests is due to the transfer of forest land to food production. This is done in several ways, such as indiscriminate shifting cultivation and exploitation for fuelwood as well as poles for shelter. The people who inhabit the areas and are involved in the process of deforestation are, on average, the poorest in the country. Thus, tropical deforestation is largely a result of economic deprivation. Any solutions designed to solve the problem must take this fact into consideration. The basic needs of the people compel them to over-exploit a resource that they will need always, or at least in the foreseeable future- a resource, the very existence of which influences not only the lives of the exploiters, but those who occupy areas far removed.
The World Bank (1978) has stressed the need to give much higher priority to the protection, conservation, and wise use of forests on a long-term basis, and to consider forestry as an important component of integrated rural development programmes. The World Conference on Agrarian Reform and Rural Development (WCARRD) held in 1979 recognized the importance of diversification of rural economic activities, including integrated forestry development, as an essential component of a broad-based rural development programme. The 78th session of the FAO Council approved "A Forestry Strategy for Development," which lays emphasis on an approach that integrates the protective, productive, and social functions of forestry activities within agriculture.
Bene et al. (1977) have pointed out that, in most of the tropical zones, trees and agricultural crops usually do best in combination. All through history, people have depended on trees for food and feed, and to maintain the productivity of the land. In the humid tropics, trees are a very productive crop and yet remove relatively few nutrients from the soil. Also, in very dry areas deep-rooted trees such Anacardia sp. (cashews) grow large volumes of valuable food where nothing else will thrive. Between these extremes of climate and land quality, trees, agricultural crops, and animal raising, if carefully planned, can be combined to the best advantage in terms of output.
Bene et al. (1977) and King and Chandler (1978) have described agro-forestry as "a sustainable management system for land that increases overall production, combines agricultural crops, tree crops, and forest plants and/or animals simultaneously or sequentially and applies management practices that are compatible with the cultural patterns of the local population." There is enough evidence to indicate that trees were used in combination with farming and animal husbandry thousands of years ago. Unfortunately some of this knowledge has been forgotten. A study of oral history among certain communities supports this view.
Shifting agriculture (also variously known as swidden cultivation, slash-burn agriculture, kaigin, ladang, chena cultivation, etc.) has been practiced traditionally by communities with strong historic, social, and economic roots in the forests. Customs and knowledge of the development of both crops and trees ensured a relatively stable balance with the ecological environment. Because of population pressures, the interval between cropping periods has been shortened in many areas, the soil does not fully recover, and the ecosystem rapidly deteriorates.
Agricultural systems that may at first glance seem haphazard are found throughout Africa and Latin America. However, different crops are grown in mixtures because the species have root systems that tap different layers of the soil for nutrients and water, they possess different solar energy requirements, they stimulate the many-storeyed physiognomy of natural tropical forests, and in general complement rather than compete with each other.
In Kenya, for example, such a system of agrisilviculture has been demonstrated. At Kijabe there was sporadic failure of seedlings in several compartments at the time of planting out, and in these no replanting was done. Now 11- to 16-year-old plantations of Eucalyptus spp. with gaps in their canopies are intercropped by local farmers, who report that there have been no reductions in their yields since the establishment of the plantations.
Nair (1979) has demonstrated that tree crops established in the manner normally followed in most forestry operations do not utilize available nutrients, water, and solar energy efficiently in the early growth stages of the plantation. Accordingly, the intercropping of these plantations with suitable food species and cash crops-especially during establishment- more efficiently utilizes the available nutrients, water, and solar energy.
Land is a limited resource that is becoming very scarce because of the current population increase. Bene et al. (1977) reckon that one needs 2-3 km² of unmanaged rain forest to feed one human being, whereas traditional methods of shifting agriculture will sustain 30-50 people on 1 km² Unfortunately, the high-yielding crop varieties that are being promoted for use in the tropics often require costly inputs such as fertilizers, water, pesticides, and energy, which few developing countries can afford. Also, suitable areas for growing and producing these high-yielding cereals are quite limited in tropical areas. This type of agriculture alone, therefore, cannot be relied upon to produce enough food for the populations; other alternative production systems must be explored. Agro-forestry stresses the planning and upgrading of shifting agriculture with a view to maximizing sustained production on less well-endowed land, whether the produce is food, feed, fuel, building material, or products of commercial value.
Charrean and Poulain (1963), for example, have demonstrated that in regions of seasonal rainfall (250 mm or more a year), careful interplanting of Acacia albida trees with millet increases millet yields by 500-600 per cent. Allowing livestock to graze on the grasses between trees and on the tree leaves and pods is a system that maximizes available land for optimal production.
The View of UNEP
UNEP recognizes the existence of opportunities such as these to increase production and improve efficiency by growing trees in combination with other crops or livestock; these practices promote environmental health and should be encouraged within national development plans. Certain problems, however, need to be overcome if programmes on agro-forestry are to be developed for maximum benefit to the human race.
First, there is an apparent lack of co-operation between workers in similar or related fields in different parts of the world. There are many cases where operators in one region remain completely ignorant of some very successful but undocumented agro-forestry trials and practices in other regions. Second, there seems to be a serious communication gap between those who carry out research and those who need to apply the results. Third, research workers in agriculture and those in forestry tend to operate in complete isolation as if the two fields have nothing in common.
UNEP believes strongly that these serious communication problems must be overcome before a sound programme can be established in agro-forestry. The wealth of scattered and un-coordinated research information must be assembled and disseminated in appropriate form to all that are involved in this work, i.e., scientists, technicians, decision-makers, and the general citizenry. Ongoing and planned research programmes must be closely integrated with national development programmes in order to ensure that they are aimed at satisfying the people's aspirations.
In the vast majority of developing countries, only a very small proportion of the results from research establishments ever reaches the people who are supposed to apply them. Quite a sizeable amount of research in agriculture and forestry, albeit in isolation, has been carried out in most of these countries over the years; unfortunately, the bulk of these results is shelved away in various annual reports, with nothing ever reaching those who need the information most -the farmers
It is UNEP's view, therefore, that probably the greatest benefit developing countries can derive from various research activities is the identification of methods for the efficient collection and timely dissemination of existing research results to field operators. This is particularly urgent with respect to the information on various research projects designed to demonstrate the feasibility of integrating forestry with agriculture and animal husbandry. Most developing countries have very efficient extension services in agriculture and livestock husbandry; in forestry the services are almost non-existent; extension services that would develop integrated programmes in agriculture, livestock husbandry, and forestry do not even fail within the planners' world view. If properly developed, co-ordinated extension services that embody forestry, agriculture, and livestock production could play a major role in the transfer of existing knowledge to the field operator at the professional, technical, and peasant farmer levels.
In the past, forestry and agriculture have been so effectively separated that the two fields have developed in total isolation. Until recently, there were grain surpluses in industrial countries and virtual self-sufficiency in most developing countries because of the existence of a lot of fertilizer and seemingly unlimited cheap energy. Foresters were therefore concerned with nothing but forest conservation and the production of timber and any programme that involved opening parts of the forest for agricultural production was unwelcome. This attitude, therefore, effectively isolated the foresters from the farmers in developing their respective industries.
Over the last few years, a combination of factors has led to serious shortages of food, especially in developing countries, and in those countries self-sufficiency in food has become a priority. Coupled with the increasing numbers of landless people, this trend places a lot of political and economic pressure on governments to open rich, forested areas for agricultural cultivation. There is less appreciation of the fact that clearing forests for farms will not be the answer to the problem.
UNEP would like to see a co-ordinated programme designed to develop methods and technologies necessary for maximizing the use of available land. Application of agro. forestry systems on marginal lands and a planned system of intercropping of agricultural crops with forest trees are regarded as important.
UNEP believes strongly that close co-operation between forestry and agricultural research workers must be developed and that a careful assessment of the potential of different trees, shrubs, grasses, and other crops is needed so that the most suitable combinations for agro-forestry can be identified. A close study of existing practices in agro-forestrv, and their modification where necessary, will not only improve outputs but also reveal important gaps in knowledge and opportunities for improving the systems. It is UNEP's belief that relevant national and international agencies must be entrusted with the important task of carrying out the necessary research to secure this new knowledge and that these agencies must take the lead in researching various combinations of trees, crops, and Iivestock.
Although agro-forestry systems are not the answer to all problems of tropical forestry development, they are low-input systems that are designed for fragile ecosystems. They are therefore complementary to, rather than a replacement for, traditional forestry development practices. Through dynamic growth forestry can play a significant role in a sustained improvement of social welfare. The forestry industry, as an important component of integrated forest management, needs a still greater emphasis so that it can meet the everincreasing demand for forest products.
UNEP places a high priority on the development of agro-forestry systems compatible with traditional practices in given areas. This priority is demonstrated by UNEP's programmes covering 1981, 1982-1983, and 1984-1989. Various projects in multiple land-use systems are either in progress or soon to be initiated. UNEP is collaborating very closely with other relevant United Nations agencies such as FAO and UNESCO in the development of agro-forestry systems. UNEP's future plans stress the importance of even closer co-operation with other UN agencies, international organizations, and relevant national institutions in the development of agro-forestry systems.