Sustainable Agriculture and the Environment in the Humid Tropics (1993) / Chapter Skim
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3 Technological Imperatives for Change
3 Technological Imperatives for Change
Pages 138-158
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From page 138... ...
The study has identified sustainable land use options suitable for a broad range of conditions in the humid tropics. That so many instances of diverse production systems was found is not surprising; that they appear to have such broad applicability across the humid tropics is of great development interest.
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From page 139... ...
It is a tool that researchers, resource managers, policymakers, and development planners and practitioners can use in devising land use strategies. The biophysical attributes in Table 3-1 include the nutrient cycling capacity of the system, the capacity of the system to conserve soil and water, the resistance of the system to pests and diseases, the level of biological diversity within the system, and the carbon flux
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From page 140... ...
bThe capacity to cycle nutrients from the soil to economically useful plants or animals and replenish them without significant loss to the environment. CThose areas having fertile soils with little slope and few, if any, restrictions to agricultural land use.
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From page 141... ...
. At higher government levels it is assumed that generating cash flow through national or international channels usually takes precedence, but with the well-being of local communities having increasing consideration.
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From page 142... ...
Perennial tree plantations, however, have a higher capacity for nutrient cycling than annual crop systems, and are better able to conserve soil and water due to the presence of a permanent, often stratified, vegetative cover. Plantations, due to the large biomass of the trees, also store about 10 times more carbon than do annual crops.
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From page 143... ...
These land uses rate high in social and political acceptability in that they promote social well-being and generate income. Cattle ranching, perennial tree crop plantations, and plantation forestry offer some desirable biophysical attributes but somewhat fewer social benefits.
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From page 144... ...
The need for widely adaptable sustainable land use systems in the humid tropics has brought increased attention to traditional systems of agricultural production and land management, and indigenous knowledge of tropical resources. Until recently the long history of agricultural adaptations among indigenous people was neglected as researchers focused on transferring modern crop production models and techniques perfected in the temperate zones.
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From page 145... ...
At the national and regional levels, general land use characteristics need to be appraised and monitored in forming national policy, allocating development resources, and fashioning broad resource use guidelines. General land use planning requires data on soil type, topography, forest cover, and other geographic factors, as well as data bases on demographic and other socioeconomic factors.
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From page 146... ...
Progress toward this goal could be hastened if: · The attributes and long-term environmental and socioeconomic effects of various land uses were better understood; · The biological and agricultural characteristics of humid tropic landscapes, watersheds, or other areas amenable to areawide management plans were more fully ascertained and useful land use classification systems were developed; and · Appropriate land use planning and development efforts, involving people and institutions at the farm, community, regional, and national levels, were further advanced. The spatial and temporal integration of land uses is fundamental to sustainable agriculture and the conservation of natural resources.
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From page 147... ...
different types of land uses in close proximity. The spatial arrangement of various land uses affects biophysical factors (for example, the presence of pollinators and pest predators or the rate of soil erosion within a watershed)
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From page 148... ...
As population density increases or decreases, the appropriate role of shifting cultivation will change. The conditions that define this role are not easily predicted.
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From page 149... ...
The land management problems that undermine agroecosystem sustainability soil erosion and sedimentation, nutrient depletion, declining water quality and availability, the loss of biological diversity, pest outbreaks, and destructive floods and fires should be addressed through coordinated responses at scales larger than the field or local village level. Solutions require critical understanding of how the mosaic of land types and land uses within a given landscape or watershed supports or destabilizes local physical, biological, and ecological functions.
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From page 150... ...
The design of forest reserves needs to be coordinated with agroecological zoning to avoid, to the extent possible, the effective destruction of habitat through isolation and fragmentation, to establish effective buffer zones and corridors, and to provide opportunities for integrated management. This is especially important in areas where forest reserves provide critical environmental services, such as the protection of upland watersheds.
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From page 151... ...
If land pressures in the village are high and markets are available, appropriate land use systems could include lowland rice with winter crop rotation, terraced rice, terraced mixed upland crops, growth of animal fodder on terrace faces, agroforest~r, mixed forest plantings, highland grazing, animal feed gathered from
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From page 152... ...
Holdridge's classification of life zones based on climatic data is an important tool for understanding plant species adaptability and comparing forest system properties, and may be of value in indicating the potential of management options most appropriate for different lands (Holdridge, 1967; Lugo and Brown, 1991~. In general, these and other land classification systems have not been designed to incorporate socioeconomic factors, such as human population density and access to roads, or important biological factors, such as the degree of biodiversity.
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From page 153... ...
The same holds for data on groundwater pollution, salinization, sedimentation rates, levels of biological diversity, greenhouse gas emissions, and other environmental phenomena (Ruttan, 1991~. In addition to collecting these data, this effort should include assessments of the social effects of environmental change on human populations, especially the health of individuals and communities.
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From page 154... ...
of the United Nations Environment Program is an example of international efforts toward making data more readily available to resource planners and other analysts who might use them to advise development decision makers. The GEMS has activities related to air and water quality in 142 countries.
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From page 155... ...
Continuous crop or crop residue cover from appropriately managed systems is crucial to maintenance of productive potential. · The efficiency and degree of utilization of sunlight and soil and water resources.
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From page 156... ...
156 SUSTAINABLE AGRICULTURE IN THE HUMID TROPICS A farmer in Zaire tends his coffee trees. Coffee is one of the country's most profitable crops and is well suited to mixed crop small farms.
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From page 157... ...
Surface runoff containing phosphorus and nitrogen enriches water and accelerates the aging of lakes, whereby aquatic plants are abundant and oxygen is deficient. Nitrate buildup in water at levels above 10 parts per million poses serious health risks to humans.
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From page 158... ...
An appropriate economic environment must be maintained to continue and expand private sector technology development in the capital-intensive, vertically integrated industries, such as poultry, hogs, fish, and silk production, and in the development of appropriate inputs. Above all, farmer-collaborative networks for integrative technology adaptation and dissemination are needed.
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