Technical
background
document
© FAO, 1996
1.1 This paper analyses interactions between the use of natural resources (i.e. land and water, plant and animal genetic resources, vegetation and soils) for food production and technical options for reducing negative, environmental impacts. Food production is carried out by people for people, and there are strong social and economic forces that affect the way food is produced. While these forces are recognized and briefly reviewed in this first chapter, their full breadth is not addressed here. (See also WFS companion papers 1 to 9).
1.2 The information was analysed according to FAO’s agro-ecological zones (AEZ) framework (Map 1). To provide quantitative analysis, a selection of 84 countries, whose boundaries fall within specific AEZ, has been taken and the relevant data concerning population and agricultural production assessed (Table 1). This selection represents over 50 percent of the world’s total land area, but excludes countries where several AEZ occur for which data cannot be separated.
1.3 If the figures of the selected countries are compared, the humid tropical regions are relatively lightly populated, although there are great regional differences. Collectively, the population density in the countries of the warm humid tropics has increased from 32.7 persons per km2 in 1970 to 51.9 persons per km2 in 1990, an annual rate of change of about 2.5 percent. Although the arid regions are also lightly populated, their density increased from an annual growth rate of 3.2 percent in the 1970s, to 3.9 percent in the 1990s. Countries in the temperate and boreal zones have dense populations but annual rates of increase are barely above zero.
1.4 Since most statistical data are based on national geopolitical boundaries and not on AEZ, there are limits to how much one can link biophysical, economic and demographic factors. Nonetheless, the agro-ecological zone system used by FAO is the most commonly accepted way to identify areas based on their agricultural potential. High-potential areas have high soil fertility (or the potential for it), reliable, adequate water supplies from rainfall or irrigation, a suitable length of growing period for producing crops, and a climatic regime that is favourable, within a normal range of variation, for annual crop production (see Table 2). They are capable of sustaining intensive crop production with existing technologies, provided care is taken not to exceed the soil’s regenerative capacity. Three categories of land with capacity to sustain intensive production are identified:
Table 1: Countries and areas selected for agro-ecological zone (AEZ) analysis
Table 2: Definitions used for the agro-ecological zones
1.5 Chapter 3 describes the natural-resource base and the major food production systems. Chapter 4 discusses the potential of improved, environment-friendly technologies. Chapter 5 reviews some of the policies and actions required to promote ecologically sustainable food production. It stresses the need for better soil and plant nutrition management, efficient use of land and water resources, improved access to energy in rural areas, safe use of pesticides and fertilizers, and the important benefits to food security of integrated production systems such as agroforesty and sylvo-pastoralism.
2.1 An increasing world population means that the arable land per person is steadily decreasing. The pressure is strongest in the Near East and Africa (Figure 1) where population densities have increased by 73 and 66 percent, respectively, over a 20-year period. These regions also have limited options to raise production because of their limited arable land base and/or weak infrastructure.
2.2 A key issue in future food supply will be the use of scarce land and water resources. One inevitable conclusion is that further intensification of food production must take place. Scientific and technological advancement has allowed this in the past, and there are many reasons to expect that it will continue to do so in the future. However, even in well-endowed areas there are limits to the environmental impact that natural and human systems can tolerate if agricultural science does not take these factors into account.
Figure 1: PERCENT INCREASE IN POPULATION DENSITY PER HECTARE OF ARABLE LAND (1969/71-1992)
2.3 Food shortages and undernutrition were major issues that led not only to the establishment of FAO, but also to extensive international cooperation in the aftermath of the Second World War. In the 1950s, it was accepted as a fundamental principle that food should be produced in the regions where it would be consumed. The developing countries were considered especially in need, and it was thought that investments in modern agricultural technologies and related infrastructure would promote development and steady food supplies. Gradually, environmental concerns gained recognition as both the public and policy-makers became more aware of the significant economic and human costs of pollution and resource degradation.
2.4 During the past 20 years, there has been a gradual evolution from technological approaches to food production towards those that address underlying environmental, social and economic factors. Among the central elements in strategies to reduce environmental impact is a better balance between reliance on technology and more information- and management-intensive approaches.
2.5 It was not until 1987 that the report of the World Commission on Environment and Development (the Brundtland Commission), Our common future, introduced the concept of sustainable development. This report helped to shift the debate from narrow sectoral interests to one that comprehensively embraced environmental, social and economic factors. It called for more attention to the quality of economic growth, social disparities, the needs of present versus future generations and balancing local, national and global concerns.
2.6 The concept of sustainable agriculture and rural development (SARD) was developed at the 1991 den Bosch Conference on Agriculture and the Environment, organized by FAO and the Government of the Netherlands. It was subsequently elaborated in Chapter 14 of Agenda 21 of the United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro, Brazil in 1992.
2.7 The form in which SARD is implemented, as recommended in Agenda 21, is based on the national context where it is applied. The use of external inputs in the developing countries is usually much lower than in the developed countries, especially in Africa. The challenge is to maintain a balance between environmental quality and impacts that arise from increased food production. For example, as pesticide use increased in Asia in the 1970s there was a parallel increase in human-poisoning environmental pollution resulting from inadequate controls on formulation and mishandling. Integrated pest management (IPM) is a preferable solution, and in most cases more economical, but it requires a shift in thinking away from purely technological solutions towards the use of participatory research, education and extension systems.
2.8 In the developed countries, there is a trend towards a more balanced use of external inputs resulting from their high costs. There are also growing numbers of farmers who use fewer pesticides and fertilizers and target their products at consumers prepared to pay a small premium for “green” produce, but production is limited relative to the total food produced. Many developing countries have green food markets that cater to consumers who wish to purchase food that has been produced using environmentally sound practices. There is ample evidence that these production strategies, in addition to being more environmentally friendly, are economically viable for the market niches to which they cater. Most large-scale commercial producers still find it economically profitable to make intensive use of pesticides and mineral fertilizers and have not widely adopted environmentally sound production technologies such as IPM and integrated plant nutrition systems (IPNS).
2.9 The worst famines of the last century were, almost without exception, the result of political instability and/or institutional failures which blocked the mechanisms required to produce, transport and provide access to food for those who were most in need.
2.10 Poverty, food insecurity and environmental impact often coexist and are characterized as a self-reinforcing cycle. It is necessary to distinguish between different types of rural poverty and how they are linked to environmental impacts (see Reardon and Vosti, 1995). One has to pose the question, “poor in what way?” in order to understand whether the poverty is primarily related to income, poor resource endowments, exclusion from access to productive resources (including investment capital) or, and most likely, combinations of these.
2.11 Natural-resource endowments and poverty interact in different ways. For example, the humid tropics of Brazil are rich in natural biological diversity and land area but limited in fertile soil for annual cropping, financial resources, labour and infrastructure; the Sahel is rich in land area but limited in land quality, physical resilience and financial resources; and Rwanda is rich in land quality and labour but limited in land area and off-farm physical and financial assets.
2.12 Income diversification within agriculture as well as in non-agricultural activities is often touted as an avenue for improving the lot of the rural poor, but many of these people are located in marginal areas that are more environmentally sensitive and offer fewer development options. Thus, poverty alleviation schemes, if they are to be successful, must address the underlying causes, whether they be natural-resource endowments, low savings and investment or other factors. China has met with some success in establishing rural and township enterprise zones that provide skilled and value-added jobs to the rural economy.
2.13 The poverty/environment degradation cycle is reinforced by low farm-gate prices that do not sufficiently compensate producers for their crop and high local transportation costs; the first prevents fertilizer from being delivered, and the second prevents produce from being delivered to markets on time. Invariably, resource-poor farmers lack crucial information about inputs, market conditions or prices for the crops they produce.
2.15 The second trend, related to the first, is in the area of planning and decision-making. Today provinces, counties, districts and other subnational entities have, on the whole, greater autonomy in the fields of strategic and physical planning and in the implementation of infrastructure works. Concomitant with this devolution from centralized development is greater international regulation in some areas [notably the establishment of the World Trade Organization (WTO) and regional trade agreements(1) and environmental conventions relating to biological diversity, climate change and desertification].
2.16 These trends are relevant because new groups are now, and will be in the future, making decisions about how to use natural resources and what levels of pollution and degradation are acceptable. More development decisions will be made at the local level, and more conditionality is implied at the international level. Since there are few absolute scientific environmental standards for sustainable food production, there will be a wide array of social, political and economic choices to be made as to how resources are allocated, for example how to produce food and protect biologically important areas.
2.17 Land tenure may be among the most important constraints on environmentally sound agriculture and is an area where government action is essential. There are numerous cases where insecure tenure holds back investment in land conservation and productivity-enhancing measures. Here, enlightened legislation can have an important positive impact. Similar action is needed for water tenure; users must recognize the scarcity of water and respond to incentives to conserve resources and invest in water-saving technology.
2.18 Trade in food and other agricultural products has been an important component for almost all of the developing countries that have experienced economic growth during the last two decades.(2) It enriches the trading partners by providing income and foreign exchange and, used properly, exploits the comparative advantage of a country to produce the crops and products it can grow most efficiently. However, price volatility means that a steady rate of return on investment is not guaranteed and farmers can be exposed to more financial risk with few options for spending on environmentally sound farming practices.
2.19 Trade in food and other agricultural products is often seen as the cause of environmental damage, especially the loss of soil fertility in the exporting country. Provisional estimates indicate that the effects of trade liberalization arising from the Uruguay Round should be almost environmentally neutral for agriculture, at least over the next five to seven years. Some shift in production is likely to take place from subsidizing countries towards lower-cost producers, a trend which on the whole is positive for the environment.
2.20 There remains a strong bias in many countries in favour of the urban sector, such as the desire to maintain low food prices and to concentrate investment in urban areas for industry, infrastructure and services. This limits the ability of agricultural producers to earn sufficient income, to save and to invest in and manage their natural resources in a sustainable manner.
2.21 The concept of urban agriculture has been emerging in recent years as a complement to the classical paradigm of producing food in distant, open rural spaces and transporting it to urban areas for consumption. Although there has not yet been much empirical analysis or experience to indicate how it can be better exploited, urban and peri-urban agriculture offers important potential to increase food production and security in areas of high population density. It can also help countries respond to shifts in dietary patterns; research in Asia indicates that people who move into cities consume more vegetables, fruit and animal products as opposed to being dependent on starchy products such as grains.
2.22 Frequently overlooked is the key role that women play in agriculture as food producers and users of natural resources. Although women often participate in the cultivation of food crops and are active managers and users of resources, in most cases they do not own land and therefore lack collateral which could give them access to credit. Less rigid and more creative lending policies on the part of financial institutions could unleash a powerful dynamic for increasing food production. The Grameen Bank in Bangladesh has successfully assisted the urban poor by putting new ideas into action based on sound economic principles that could equally be applied in many rural areas.
2.23 Emphasis on producing cash crops for export tends to be dominated by larger producers and controlled by men; subsistence crops are usually found on the poorer soils where, for survival, women overexploit the land to meet household needs and in the process become agents of land degradation. Few research programmes have been sensitive to the role of gender in food production, labour distribution or decision-making processes and have thus lost important opportunities to increase efficiency, productivity and sustainability.
2.24 Human activities in food production take many forms: vegetative clearing, soil tillage, drainage and introduction of new plant and animal species. Their effects depend on the extent of the exploitation. For example, clearing an isolated patch of forest, although destructive for the species living there, may create less forest impact than selective logging over extensive areas. Temporal impact depends on the frequency of disturbance and the permanency of the effects: a single cutting of tropical forest will be followed by secondary regrowth so that in about 200 years the original biomass, if not necessarily the species composition, will be restored.
2.25 The chain of on- and off-site effects further complicates the food/environment nexus (see Figure 2). Examples of on-site effects include removal of indigenous vegetation, increased weed or insect infestation, and soil compaction caused by animal trampling or heavy machinery. Off-site effects include downstream silting resulting from soil erosion, off-site runoff (through concentration of water flows into lower-lying areas) and eutrophication or pollution of surface and groundwaters by excess fertilizer use.
Figure 2: SOME INTERACTIONS AMONG POPULATION GROWTH, FOOD PRODUCTION AND ENVIRONMENTAL IMPACTS
2.26 In some cases, population growth (Figure 3) has led to land-use intensification and increases in land productivity on already-cleared land. For example, India’s cereal production has increased from 87 million tonnes in 1961 to 200 million tonnes in 1992, but on an arable land base that has remained almost constant, thus helping to limit the extension of cereal cultivation on to other lands (Figure 4). In other cases, population growth has not been matched by increases in productivity and has led to expansion of land used for food production. In these areas, widespread in Africa, productivity on newly cleared land has declined after a short time, triggering further expansion.
Figure 3: TRENDS IN AVERAGE POPULATION DENSITY BY AGRO-ECOLOGICAL ZONE
Figure 4: LAND SPARED IN INDIA BECAUSE OF GAINS IN PRODUCTIVITY
3.1 The ways in which natural resources are used for food production are strongly influenced by human, economic, cultural and social conditions. This is evident in the great variety of changes made to the natural environment through the modification of landscapes, the use and removal of natural plant and animal species and varieties and the manipulation of water and soils.
3.2 Level land with favourable climate and fertile, well-drained soils is a highly valuable natural resource, but such areas are also sought after for industrial activities, housing and recreation. With 45 percent of the world’s population now living in urban areas, many thousands of hectares of the most agriculturally productive land are lost each year as cities expand, motorways and airports are constructed, and new commercial and industrial enterprise zones are created. Urban and rural settlements now cover some 4 million km2.
3.3 Structural modifications to the landscape have been made by human beings throughout history. Locally, these have significant effects on the land surface and hydrology, as the natural vegetation and the soil, subsoil and even underlying geological strata are moved to provide a new, level surface. Spectacular examples of terracing may be found in China, Indonesia, the Andean countries of South America and other parts of the world. In China alone there are approximately 26.6 million hectares of terraced land.
3.4 The impact of food production systems on the environment reflects the characteristics of agro-ecological and socio-economic conditions around the world. For the purposes of this analysis, the following zones were used: warm humid tropics, warm seasonally dry tropics, cool tropics, arid regions, subtropics (summer rains), subtropics (winter rains), temperate zone and boreal zone.
3.5 Increased food production is possible in the warmer AEZ, but soil, plant nutrition, pest control and moisture management are critically important. On the other hand, the cooler temperate areas of the world have higher per caput food production because of more favourable soil and climate and capital available for investment.
3.6 The current extent of cultivated land throughout the world is about 1 400 million hectares (of which 270 million hectares are irrigated), but there is considerable variation in the percentage of land used for arable cropping in the AEZ. Arable cropping occupies just over 30 percent of the total land area in the temperate zones and the warm seasonally dry tropical zone, with the least amount in the arid zone. The wide range of crops that can be grown in the cool tropics increases the area of cultivated land to between 15 and 20 percent of the total land area.
3.7 Many farming systems reflect the characteristics of their agro-ecological zones. However, some systems transcend these zones, especially irrigated farming, subsistence systems, mixed farming, home gardening and horticulture.
Irrigated farming systems
3.8 Irrigated lands occupy a relatively small area globally, less than 300 million hectares (about 15 percent of all arable land), but they produce 36 percent of all crops and more than half of the total grain production of the developing world. Between 1991 and 2010 it is expected that the area of irrigated land will increase from 248 million to 311 million hectares. This type of farming system can be highly productive; in many areas of Southeast Asia it has remained productive for many centuries.
3.9 In arid regions, some 10 percent of all irrigated land is affected by salinization, and the area is increasing. Water-use efficiency is low; at least 60 percent of the irrigation water does not reach the plant because of seepage and deep percolation from canals. In the fields, overuse of water and a lack of effective drainage systems cause waterlogging and salinization. Salinization affects 23 percent of China’s irrigated land and 21 percent of Pakistan’s. Environmental risks associated with large-scale irrigation include non-point source pollution, build-up of pesticide residues, pest resistance, salinization and health-related water-borne diseases such as bilharzia, malaria, diarrhoea, river blindness, cholera and typhus.
3.10 Extraction of fresh water from aquifers in coastal plains can lead to saltwater incursion. Once displaced, the fresh water cannot easily be restored and the land becomes unproductive. Overextraction of water for irrigation has resulted in the dramatic shrinkage of the Aral Sea, and lower river flows have caused saltwater incursion into the delta of the Nile in Egypt and the Ganges-Brahmaputra in Bangladesh. Any rise in sea level as a result of global warming would compound the situation.
Subsistence-oriented practices
3.11 Nearly all subsistence-oriented farming systems now include cash crops, some of them perennial. The revenue can alleviate problems that small farmers experience because of their restricted access to credit, but it can also increase the risk by requiring greater reliance on external inputs. Cash crops tend to occupy the more fertile areas, while food crops are relegated to lands of lower potential (although the reverse also occurs, leading to declining yields of perennials such as cocoa in Africa). Gender considerations are important because in developing countries women are often responsible for cultivating food crops but lack capital, have limited educational opportunities and spend a large proportion of their time in work that is unpaid. This combination forces women to overexploit the land available for household needs, and they become both agents and victims of environmental degradation.
3.12 Land degradation occurs mainly in the form of soil-nutrient mining as a result of low fertilizer availability, use of marginal land because of land shortage or tenure constraints, soil erosion resulting from poor knowledge and lack of income to carry out protective measures, and pollution by agrochemicals (when used) because of insufficient understanding of application methods.
Mixed-farming practices
3.13 Mixed farming is based on a diversified combination of plant and animal husbandry, often including forestry. In many zones these mixed systems are being supplanted by specialized systems that may be more productive but are more risk prone. Mixed systems offer many environmental advantages, such as the recycling of crop residues and animal wastes, maintenance of soil organic matter, animal traction, windbreaks, diversified sources of nutrition and income, soil conservation, increased agro-biological diversity, and biofuels. In terms of the combined environmental and economic benefits, mixed systems merit greater promotion, especially among poor farmers. Much less research has been done on these kinds of systems than on others.
Home gardening and horticulture
3.14 Home gardening and small-scale horticulture take many forms and can make important nutritional contributions to millions of food-insecure households. Traditionally, these systems present a permanent land cover and involve little environmental risk, since they tend to be carefully managed, closed systems using manure, night-soil, ashes and composted kitchen waste as fertilizers. However, home gardening is changing as a result of urbanization and specialization. Although a greater amount of staple foods is grown, there is also more indiscriminate use of agrochemicals.
3.15 At the other end of the spectrum, highly specialized, even computer-controlled greenhouses have been built to produce high-value crops, for example in the Netherlands, where about 6 percent of the cultivated land is devoted to horticulture. These systems are expanding, notably into Southeast Asia. Major environmental problems are pest control and energy demand (for heating or cooling) and the disposal of polluted waste water. However, considerable progress has been made in designing closed systems with total climate control, including CO2 fertilization, which allows production levels that approach the biological maximum attainable.
3.16 Practices that have a beneficial effect on specific kinds of soils used for agriculture include deep cultivation, liming of acid soils, addition of organic materials, fertilizer applications, sedimentary additions during irrigation, drainage and control of soil erosion.
3.17 Additions of organic matter to soils stabilize soil structure, improve moisture and nutrient retention and provide necessary minerals for healthy plant growth. The impact of adding mineral fertilizers to soils in order to increase productivity has been dramatic, and without them high crop yields cannot be maintained. However, they are far more efficient when used as one element in a comprehensive plant nutrition management strategy.
3.19 Water erosion can occur as an insidious loss of a few millimetres of topsoil each year. The evidence points to a continued increase of erosion on cultivated lands despite the availability of technology to limit its impact. The erosion of 1 cm/ha/year of topsoil is equivalent to a loss of between 100 and 150 tonnes of soil, and each 100 tonnes of soil lost per hectare may include a loss of 2 000 to 2 500 kg/ha of humus, 200 to 300 kg/ha of nitrogen, 100 to 200 kg/ha of phosphorus and 500 to 1 000 kg/ha of potash.
3.20 Reductions in yield can be significant (up to 34 percent) even at a level of soil loss of 5 percent per year. A study of crop productivity on eroded soils in Africa suggests a reduction of 2 to 5 percent for each millimetre lost. In Africa as a whole, yield reduction caused by past erosion has been estimated at 9 percent.
3.21 Soil erosion by wind occurs throughout the arid regions and in seasonally dry AEZ as well as on sandy and silty soils of other regions during periods of drought; most widely in Africa and southwest Asia. Over 22 percent of all land in Africa north of the equator is affected by wind erosion. Loss of vegetation through overgrazing and drought has extended the desert 90 to 100 km further south in the Sudan. Wind erosion is a serious problem in many countries, including Mali, Mauritania, the Niger and Nigeria, and it also affects parts of the western United States.
3.22 Depletion of soil fertility and the accumulation of substances that inhibit plant growth are the main consequences of the chemical degradation of soil. Leaching and removal of plant nutrients by crops gradually lowers the fertility status of certain soils. As a result, crops are stunted and the sparse cover leaves the soil with insufficient protection to resist erosion. The GLASOD survey (UNEP/ISRIC, 1991) estimated that at least 6 million hectares of soils have been degraded by acidification, while nutrient decline has been recognized in 135 million hectares worldwide, with Africa (see Map 2) and South America among the main areas affected.
3.23 Compaction of soil resulting from the use of farm machinery changes soil structure and reduces water and root penetration as well as root growth and density; it also affects microbial activity and increases root diseases. It affects 68 million hectares, mainly in Europe (33 million hectares) and to a lesser extent in Brazil, western Asia and Africa. As the use of wheeled farm equipment increases, losses in yield also increase and cause financial losses to the farmer.
3.24 Domestic animals are a crucial element in meeting future global food requirements. At present, 4 500 breeds from 40 or more animal species provide at least 30 percent of human needs in the form of meat, milk products, eggs, fibre, draught power, manure and fuel. Livestock provide for 60 percent of the draught power needed for cultivation and transport of crops and serve as a major cash reserve for small farmers. The genetic diversity of these animals and their wide environmental adaptation underpin the productivity and sustainability of agriculture, representing the only assurance of food security for the estimated 12 percent of the world’s population whose livelihood depends solely on livestock. As with food crops, there has been a tendency to concentrate on a relatively narrow genetic base, leaving many domesticated breeds vulnerable to extinction. Few developing countries are actively conserving livestock genetic resources.
3.25 Aspects of livestock farming that have a negative effect on the environment include overgrazing, trampling, deposition of wastes, water depletion and pollution and the reduction of genetic diversity. Of considerable debate in some countries is the use of arable land to produce grain for animal feed, which some groups perceive to reduce the food that could be available to lower-income, food-insecure households. Indirect benefits of animal husbandry are the use of animals for power, supply of manure and the introduction of nitrogen-fixing fallow pastures in rotation with arable crops. Important by-products include leather goods, although environmental problems can result from processing in tanneries.
3.26 Livestock ranching is an important part of the economy of the warm, seasonally dry tropics and a significant component of many temperate zone farming operations. Clearing of tropical forest for ranching, strongly influenced by government policies, has had devastating effects in some Latin American countries.
3.27 The area used for grazing is more extensive than that of croplands, totalling 3 424 million hectares. Approximately two-thirds of permanent pastureland is in the developing countries, and the percentage area decreases through the subtropics and temperate zones to the boreal zone, where there is only slightly more than 10 percent of land given over to permanent pasture. The warm humid tropics also have a small percentage (10 to 12 percent) of pastureland (Figure 5).
3.28 In the warm, seasonally dry tropics and arid AEZ, such as the Sahel, extending into Kenya and the United Republic of Tanzania, and the southwestern zone of Botswana, Namibia and parts of Zimbabwe, pastoral systems, based mostly on cattle or goats, predominate. In the past, these systems were highly mobile and extended over a large area which allowed vegetation to recover. Growth of the human population has led to conversion of pastures to arable land, thus concentrating livestock on a reduced land area. In the seasonally dry zones, animal numbers tend to increase during years of normal rainfall, so that in times of drought there are more animals than the land can support. The northern temperate zone equivalent of drought is a late, cold spring with heavy snowfall prolonging the winter and delaying the regrowth of pastures.
Figure 5: CHANGE IN SHARE OF PERMANENT PASTURE BY AGRO-ECOLOGICAL ZONE
3.29 Fisheries play a significant role in food supply, income and wealth, supporting more than 120 million people, and providing about 19 percent of the total animal protein consumed in the developing countries. The world’s total production of fish (including finfish, crustaceans and molluscs) increased from around 20 million tonnes in 1950 to about 100 million tonnes in 1989. In the 1990s, marine capture fishery landings have been declining. This decline has been offset by increases in aquaculture production, but annual production has reached a plateau of about 70 million tonnes for direct human consumption.
3.30 In 1993, marine capture fisheries contributed 79.5 million tonnes of fish as compared with 6.5 million tonnes caught in inland waters. Production by inland and marine aquaculture was 10.7 million and 5.6 million tonnes, respectively. Almost 70 percent of those stocks of marine fisheries for which assessments are available are at exploitation levels close to or beyond the maximum sustainable yield.
3.31 Capture fishery practices may damage aquatic habitats, affecting bottom fauna, sea-grass beds and coral reefs through the intensive use of mechanized fishing gear, such as bottom trawls and dredges, and the use of explosives. An average of 27 million tonnes of unprofitable species are discarded each year in commercial fisheries such as shrimp trawling, bottom trawling, long-line and pot fisheries and high-seas driftnet fisheries. Given the growing gap between supply and demand, higher prices are inevitable which could pose a threat to the food security of some rural poor who rely on fish as a major source of protein.
3.32 The environmental effects of aquaculture and culture-based fisheries come primarily from intensive systems (e.g. cage culture of salmon and large-scale shrimp culture in coastal areas) which involve excessive nutrient and organic enrichment of water bodies, degradation of wetlands and the loss of biological diversity from the introduction of exotic species.
3.33 Many land-based sources of pollution arising from human activities have an adverse impact on the regenerative capacity of aquatic resources in near-shore and coastal areas. The prime cause of the reduction in fish abundance is due to the loss of habitat combined with industrial, urban and agricultural pollution, landfills, damming and diversion of rivers, clearance of mangroves, sedimentation, resource mining and deforestation. Degradation of aquatic environments can affect fishery resources both in inland waters as large as river or lake basins and in coastal waters or enclosed and semi-enclosed seas.
3.34 Wetlands, comprising 48.7 million hectares worldwide, are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary. Their water can be static or flowing, fresh, brackish or salty, including areas of marine water to a low-tide depth not exceeding 6 m. The characteristics that make wetlands valuable for agriculture and food production also make them vulnerable to degradation.
3.35 Agricultural practices present a number of threats to wetlands. Watershed degradation may produce erosion that silts up the wetlands and impairs their biological and hydrological systems. Flushing of fertilizer and other chemical residues into wetland areas can create eutrophic conditions or poison plants and animals.
3.36 Among the wetlands, mangroves cover 15.5 million hectares, their greatest extent being in Asia, with 6.28 million hectares; tropical America and Africa have 5.78 million and 3.40 million hectares, respectively. Mangrove areas are used locally for agriculture, mainly rice, and are heavily exploited by rural people on all continents for a number of wood and non-wood products; but their most important contribution to food production and security is in the conservation of fishery systems, as they represent important spawning grounds for a number of species, as well as being production areas for shrimps, oysters, mussels and other shellfish. Conversion to aquaculture or the felling of mangrove forests can reduce reproductive habitats for many economically important fish species, simultaneously increasing the vulnerability of inland agriculture to storms and floods.
3.37 Food production has had several important but opposing effects on biological diversity: it reduces the extent of natural areas and the diversity of ecosystems and wild species they contain; and it develops, over centuries of domestication and adaptation, an agro-biological diversity made of the multiple landraces of crops and breeds of livestock. This pool of agro-biological diversity has been reduced as traditional landraces and animal breeds have been displaced by the introduction of a more limited number of high-yielding varieties and breeds with a narrower genetic base. This is reported to be the most important cause of genetic erosion.
3.38 Ecosystems contain biological diversity which is part of the natural capital of the earth. Although the total number of plant and animal species is unknown, a commonly cited estimate is between 13 and 14 million, of which only 1.75 million have been scientifically described. Between 5 and 20 percent of some groups of vertebrates and plants are already listed as being threatened with extinction. The primary reason for rapid loss of biological diversity during the last 50 years is the conversion of natural habitat, primarily forest, to other uses, especially food production.
3.39 Domesticated species are a tiny fraction of animal and plant life: of 320 000 known vascular plants only 3 000 are regularly exploited for food, and only 30 of an estimated 50 000 terrestrial vertebrates and more than 200 species of fish, crustaceans, molluscs, frogs, turtles and aquatic plants are used for food. Among domestic animals, 30 percent of all breeds of livestock have less than 20 breeding males or less than 1 000 breeding females remaining. The genetic diversity of these species, in both improved and other races as well as in related wild species, is vital to future food production, which requires a broad range of agro-ecosystems and genetic resources that are adapted to local conditions.
3.40 Pest and disease resistance, tolerance to drought and other desirable traits are among the important benefits of genetic diversity in crops. In recent years efforts have been made to collect and document genetic characteristics of wild and domesticated species, especially landraces, in order to identify valuable characteristics of use to agriculture. This material has been stored ex situ in gene banks. Recently more attention is being given to the in situ conservation of wild relatives in protected areas and on-farm conservation of landraces. Such dynamic forms of conservation allow continued adaptation of plant varieties, including co-adaptation with insect pests and diseases.
3.41 Some cultures subsist by hunting and gathering food in forests, obtaining sufficient fruits, nuts, leaves, gums and wild game in addition to fibre, fodder and fuelwood. This occurs locally in South and Southeast Asia, some West African countries and parts of Latin America and Europe. People derive benefit from forests through collection, processing and sale of forest products (e.g. mushrooms, nuts, berries and game).
3.42 The percentage of forest compared with the total land area in 84 countries and the trends that emerge over a 20-year period are shown in Figure 6. The greatest change is in the seasonally dry tropics, where the annual decrease has been 0.69 percent during the past decade. The figures for the warm humid tropics do not show a clear trend, perhaps because of the regrowth that is taking place in many cut-over areas.
3.43 Shifting cultivation, a traditional method of land use still widespread in areas of low population density and infertile soils, involves clearing an area of its natural vegetation, cultivating the land for a two- to five-year period, and then leaving it fallow until the land regains its fertility, whereupon the cycle is repeated. Chronic degradation is caused by shifting cultivation when the fallow period is not long enough for restoration of vegetative cover and soil fertility.
3.44 With a low population pressure, the natural regrowth of trees and other biomass is sufficient to meet the demand for fuelwood, but when shifting cultivation is intensified it affects an area’s biological diversity by consuming a larger land area and reducing the time available for regeneration. In addition, when population pressures force the cultivators to reduce the length of the fallow period, there is a loss of soil fertility, resulting in lower crop yields and less wood for fuel. This may force farmers to expand their cultivation on to other wooded and forest areas.
3.45 Overexploitation of a forest product or unsound logging practices can degrade the forest vegetation and harm the wildlife habitat. This damage not only affects the forest’s food and wood resources, but may also affect soil, water and food production systems downstream. Opening up a forest area for habitation or agricultural expansion, as in tsetse eradication programmes, or driving logging roads through previously inaccessible forest areas, increases the potential for uncontrolled use and overexploitation.
Figure 6: Change in forest area by agro-ecological zone
3.46 Nearly 2 000 million people are dependent on biofuels (wood, crop residues, dung, etc.) as the main source of household energy. In the tropical zones, fuelwood use is between 1.5 and 2.5 kg of wood per person per day, whereas the amount used in temperate zones is less than 0.5 kg per person per day. A general decline in per caput fuelwood use (Figure 7) is a result of populations increasing faster than fuelwood consumption, greater scarcity of fuelwood and substitution by fossil fuels. In Latin America, substitution of wood by other fuels has led to a decline from 356 000 barrels of oil-equivalent consumed as fuelwood in 1970, to 307 000 barrels in 1990. However, in Central America, an area with a strong food-security challenge, the share of fuelwood increased from 42 to 50 percent of the total energy consumed during the same period.
Figure 7: Trends in fuelwood use by agro-ecological zone
3.47 In absolute terms, the total volume of wood consumed as fuel is increasing in the world. Around large urban centres and where there is a concentration of industrial and commercial activities using wood fuel, great pressure is exerted on neighbouring forests and woodlands. Since in the warm tropics wood is mainly used as fuel for cooking, any technical innovation and/or dietary change will serve as a substitute for wood and reduce its consumption.
3.48 As fuelwood becomes scarce, it is often substituted by dung, whose fertilizing effect is then lost. However, the population’s need for fuelwood and charcoal can become a driving force for tree planting using agroforestry, community or commercial plantations on private and public lands where they can be a source of income and employment, thus paying environmental, social and economic dividends.
4.1 Sustainable food-production systems must meet three goals:
4.2 Achieving these goals requires a different approach to food production than has been used in the past. Nearly all technical options for increasing food production have environmental, social or economic trade-offs, but important benefits can be realized by concentrating on practices that build on ecological characteristics such as diversity, resilience and efficient energy use.
Soil conservation
4.3 Although the effects of erosion on crop yields are important at plot level, the off-site effects (e.g. on fish resources and habitats) are also paramount at the watershed level. In some cases ecological measures such as live hedges, grass strips and orchards, combined with simple bench or ridge terraces, can be more successful than the more costly stone-wall terraces. Many techniques have been employed to suit prevailing soil, climate and land-use conditions or practices. These include reduced tillage, deep ploughing, contour ploughing, strip or multiple cropping, rotation, green manuring, mulching and fertilization.
4.4 In the arid zone and in drier parts of the seasonally dry tropics, there is considerable scope for applying soil and water conservation techniques, as has been demonstrated by FAO’s Keita project in the Niger. Using various participatory techniques, trees have been planted for fuelwood, for their food value and as windbreaks; water harvesting has been employed, and measures to counter wind and water erosion have been undertaken.
4.5 In drier areas, measures may be as simple as smoothing the soil surface to direct runoff towards basins where it can be collected, or creating ridges with gentle gradients to gather water from uncultivated slopes and channel it on to the cultivated lands, as is practised by the Nabatean people at Advat in the Negev Desert.
Water resources
4.6 Sustainable water use requires that adequate flows, especially during critical low-flow periods, be maintained to protect stream, river, lake and wetland systems. This same water is used for growing crops, fishing, food preparation, preservation of foodstuffs and in some cases to generate energy. As water flows from the watershed regions to the sea, it is used and reused many times, changing in quality and amount. Agricultural or forestry activities in upstream areas can have a negative impact on users downstream if runoff contaminates the water with sediment, fertilizer and pesticide residues. By contrast, areas that keep their natural forest cover and wetlands function efficiently to maintain water quality, regulate supply and maintain riparian habitat for fish and other animals.
4.7 FAO has estimated that the potential exists, based on physiography and soil conditions, for an eventual total of 400 million hectares of irrigated land, three-quarters of which would be in the developing countries. Irrigated areas are 2.5 times more productive than rain-fed agricultural land, and there is a strong presumption that their extent (some 300 million hectares at present) will increase. However, expansion beyond present levels is constrained by the shortage of suitable land, limited water supplies and the high cost of installing large-scale irrigation schemes. In many cases it is more effective to improve the management and production efficiency of existing irrigated areas than to open up new irrigation schemes.
4.8 Waterlogging usually results from overuse and/or poor management of irrigation water. Lining and covering of water conduits from the storage dams to the point of delivery improves water usage and at the same time reduces the risk of a rise in the water-table in many irrigated areas. This procedure needs to be applied to the 11 million hectares of land in Asia that have been degraded through waterlogging, but it would also benefit areas suffering from salinization, which limits the productivity of 50 percent of the world’s irrigated land. Waterlogging and salinization impacts can be further reduced in most cases by more investment in education and management capacity rather than in drainage and soil improvement works.
4.9 Arable cropping, particularly in the tropics, poses significant environmental difficulties in that regular soil tillage opens the soil and leaves it vulnerable to erosion. In addition, intensification through reduced fallow and multiple cropping implies the need for attention to soil fertility and pest management; traditionally this has meant more use of mineral fertilizers and pesticides. However, alternative technologies, such as IPM and IPNS, will need to be applied ever more intensively.
Integrated plant nutrition systems
4.10 Plant nutrients are in the soil, in manure and in crop residues, forming part of the nutrient flow. Nutrients stored in soils are available for crops, but those in crop residues and organic manures are only available as they are broken down by bacteria. IPNS are designed to balance the nutrients available to the farmer from all sources, including mineral fertilizers, for their optimal use.
4.11 Organic matter helps to maintain good physical soil structure and microfauna needed for water-holding capacity, aeration and the conditions to supply nutrients to plants. There is no fundamental difference whether plant nutrients come from organic or mineral fertilizers. However, organic sources help maintain soil structure and texture, usually involve minimal direct cost to the farmer and when combined with the careful application of mineral fertilizers, enhance their effect on yield and help to compensate for nutrients lost in food production.
4.12 Many farmers do not achieve good yields because the fertilizer supply is inadequate to meet demand, the range of fertilizers is limited and delivery is unreliable. Inappropriate applications can be counterproductive, and the non-availability of nutrients at certain stages can reduce the beneficial effects of previous applications. For example, mango is fertilized to enhance flowering, but if insufficient nutrients are available during ripening, fruits fall from the tree before they are ripe.
4.13 It is therefore necessary to address the problems of plant nutrition in an integrated way and to maintain the overall balance and flow of soil nutrients, seeking maximum efficiency and reducing waste and loss (Figure 8). To this end, research, education and training activities should be more focused on the promotion and application of IPNS.
Figure 8: Simplified diagram of nutrient flows
Integrated pest management
4.14 Since their introduction 50 years ago, synthetic pesticides have become the dominant response to pest problems in agriculture. Their use has led to more stable yields and increased fertilizer use. However, in numerous cases this approach has proved to be unsustainable and inefficient because of the development of pest resistance, the rising costs of pesticides, the loss of beneficial insects and negative effects on human health and the environment. The response to these difficulties has been a gradual shift towards IPM, a system in which farmer participation and biological control are fundamental.
4.15 IPM empowers farmers to take direct control of pest management in crop cultivation. Farmers themselves regularly monitor the health status of their crops and the activity of beneficial insects and, based on this information and their knowledge, decide on appropriate control measures. In general, IPM combines a number of available control techniques that, among other things, keep pesticides and other interventions at levels that are economically justified and environmentally safe. Four technical elements can be distinguished: sound crop management wherein farmers apply all available knowledge to grow a healthy crop; adoption of practices such as monitoring of beneficial insects and using understanding of the ecology of pest life cycles to enhance biological control, which uses natural predators and ecological characteristics; use of crop varieties bred for durable pest resistance or techniques such as genetic engineering of host-plant resistance, in particular to viruses; and, as a last resort and only when the net effect on natural control measures will be positive, chemical control.
4.16 Major increases in production in developing countries can be achieved by a combination of IPNS and IPM technologies. Successful implementation of these options, however, requires strong involvement by the people who will be using them. Policies that reduce pesticide and fertilizer subsidies need to be directed towards increased farmer training, and reorientation of research, education and extension services to ensure that they are driven by farmers’ actual needs. Governments should review policies relating to the purchase, registration, formulation, application and disposal of pesticides, taking into account the 1985 International code of conduct on the distribution and use of pesticides as amended in 1989 to incorporate the principles of prior informed consent (PIC) (FAO, 1990).
4.17 As standards of living rise in many parts of the world, increasing numbers of people will demand more meat and dairy products in their diets. In 1994, world meat production amounted to 184 million tonnes, or 33 kg per caput. Globally, about 16 percent of cereals, 20 percent of starchy foods and 3 percent of oilseeds are used for livestock feed. The demand for cereals to feed livestock is forecast to rise to 30 percent of total production by the year 2050. As a result, there will be increased pressure for land to produce cereals for animal feed.
4.18 Permanent pasture occupies 3 424 million hectares and is the most widespread of land uses. Multispecies grazing systems, long used in traditional pastoral systems (cattle, horses and small animals in northern Asia) assure better use of available feed and maintenance of the vegetative balance. An energy-efficient alternative is to keep the animals confined, and there is a trend towards increased reliance on fodder crops and feed concentrates rather than free-range grazing.
4.19 Loss of genetic resources will diminish the capacity of plant and animal breeders to respond to changing conditions and demands on the food industry. It is necessary to document existing animal genetic resources; to promote increased productivity of a wider range of animal genetic resources; to make these available to agriculture; and to maintain the unique genetic resources not currently of interest to farmers. The management of animal genetic resources must involve a wide range of governmental and non-governmental organizations (NGOs) at a scale similar to that already attained for plant genetic resources.
4.20 Emissions of methane from ruminants are forecast to double in the period 1990 to 2050, and difficulties are expected in the disposal of animal wastes. Through appropriate feeding and genetic improvement, methane emissions can be restricted, and methane from slurry can be used as biofuel. Direct and indirect pollution abatement costs in the livestock industry are reported to be only 0.72 percent of total costs, which allows considerable margin for further reducing impacts from this sector.
4.21 The average annual supply of fish available for direct human consumption from marine capture fisheries was reported to be 50 million tonnes in the period 1990 to 1993. If no action is taken to reverse present levels of overfishing, declines in supply from marine fisheries can be expected. Major inland fisheries may face similar prospects. Aquaculture production, though expected to continue to grow, may also be constrained by poor management and its attendant environmental impacts.
4.22 Measures likely to bring about environmentally sound fisheries resource management include restrictions on the present free and open access to resources, but this requires ensuring equitable allocation of resources and establishment of use rights. In artisanal fisheries, use rights are particularly important in protecting fishermen from unequal competition with industrial vessels.
4.23 Measures to control fishing, however, depend on extensive participation among those affected if acceptable and durable agreements are to be reached; this entails adoption of equity principles and devolving management to the lowest practical level of responsibility. Where allocation is difficult, conventional fisheries management measures need to be strictly applied, including closure of critical fishing ground habitats, regulation of fishing gear, closed seasons, catch quotas and minimum size at landing.
4.24 The fisheries and aquaculture sector also needs to be taken into account in land-use planning, river-basin and watershed management and integrated development and management of catchment and coastal areas.
Use of natural forest products
4.25 Food gathering in humid tropical forests, while ecologically sound, can support only a limited number of people. There is scope for the use and export of non-wood forest products for development, as occurs in some parts of the Amazon basin. Most of these are non-food products such as pharmaceutical materials, although mushrooms, honey, fruits and nuts are also important. The income from this type of use can play an important role in the food security of people living in and around the forest by allowing for diversification of both incomes and sources of nutrition.
4.26 Fuelwood is an essential resource required for food preparation and for food preservation through smoking and drying. When the demand for fuelwood exceeds the natural forest growth, the fuelwood supply can be increased locally through agroforestry and plantations of locally adapted species.
4.27 One option for coping with wood shortages in the humid and subhumid zones includes forest fallows planted with fast-growing species that can produce fuelwood in a relatively short time. Around homesteads and in peri-urban areas various tree species can be used for production of fruit, furniture, brooms, rope and twine which provide useful additions to household income, often going directly to women and assisting in food security.
Agroforestry
4.28 A wide variety of land-use systems use woody perennials (trees, shrubs, palms, bamboo, etc.) on the same land-management unit as agricultural crops and/or animals. Some of the more common (and most researched) systems in the humid tropics include plantation crop combinations (e.g. shade trees over cacao, coffee or tea), plantation crops (e.g. coconut) with livestock, home gardens or multistorey tree gardens, and improved fallows in shifting cultivation systems.
4.29 Windbreaks and shelterbelts, multipurpose trees on croplands and sylvo-pastoral systems (trees and shrubs on ranchland or pastureland) are common agroforestry systems in semi-arid and subhumid zones which increase the production of wood products (fuelwood, poles, timber), food (fruits), fodder or various other non-wood products (medicines, fibres). They also improve the microclimate for plants and/or animals by providing shade and raising humidity. Planting trees as live fences and for fruit or supplementary fodder production is common in many countries.
4.30 The yields of some food crops can increase under agroforestry systems but have been thoroughly researched for only a few uses (i.e. windbreaks, parklands, shade trees over tree crops and alley cropping) (Table 3).
4.31 Other benefits of agroforestry include enhancing the value of the crop produced and diversifying farm incomes. For example, windbreaks established to protect fruit-trees or other horticultural products have not increased total crop yields but have resulted in a higher-quality product worth more on the market. Maintaining shade trees over cacao plants provides shelter for the tree crops in their first two years of establishment, reduces soil erosion, provides nutrients when fertilizer is not applied and reduces pest incidence, diseases and weeds.
4.32 It is widely agreed that an effective way to conserve natural biological diversity is to improve productivity on already-cleared lands and to establish suitable mixed-use buffer zones to protect existing areas. It is equally important to conserve agro-biological diversity by retaining a wide variety of beneficial plants, animals and insects from different races and subspecies.
4.33 Crop diversity can be enhanced through crop rotation (temporal) and sequences (spatial) in the form of cover crops, intercropping and agroforestry or crop/livestock mixtures. The release of a wider range of varieties and participatory and site-specific approaches to plant breeding can also make a positive contribution. Crop and varietal diversification helps to regulate pests and contributes to soil nutrition and conservation.
Table 3: Types of agroforestry systems that can increase crop yields
4.34 In general, the wider the range of species present in an ecosystem, the more stable it is and the greater its resistance to disturbance. Although the gross output of diversified cropping systems may not be as high as that of specialized monoculture systems, they are generally less vulnerable to production risk. Traditional crops, the cultivars of the nineteenth century and varieties of rice, roots and tubers used by indigenous people also possess a diversity which counters the risks from pests and disease. Reduction of the genetic variability of plants and animals reduces their ability to adjust to stress. Hence mixed plant/animal systems generally provide flexibility, productivity and sustainability, characteristics that are particularly well suited to rural, food-insecure populations.
4.35 Because of the success of the green revolution that started in the 1960s, some groups are calling for a similar effort to increase food production in the poorer, most food-insecure regions. Map 3 shows the distribution of productive areas of the world with the estimated agricultural productivity classes given in grain equivalents [the amount of cereal grains (in t/ha/year) that could have been grown with the energy used by the current crops or livestock]. Large parts are seen to have low productivity relative to what could be produced under higher input levels (Map 4). Map 5 presents an estimated yield gap, produced by overlaying of Maps 3 and 4.
4.36 This yield gap, the difference between what researchers can produce under experimental conditions and what farmers actually achieve, is seen by many to be the primary barrier to increasing food production. A number of factors would be required to launch a second green revolution, but they should not be limited to the scientific challenge of reducing the yield gap. They include the need to accompany science and technology with participatory enabling mechanisms, training and institutional and policy reform.
4.37 Some persons have adopted the term “double green revolution” or “new green revolution”,(3) since the aim is not just to raise food production but to do so in an environmentally sound and sustainable manner. The green revolution as experienced primarily in Asia in the 1960s and 1970s helped immensely to raise food production but carried with it a number of avoidable environmental consequences resulting from the failure to retain many important principles of agro-ecology, such as diversity and resilience, which benefit the very people who need food.
4.38 Asia, which clearly benefited from the green revolution, is only barely able to maintain its gains because of population growth and limited arable land. Africa, which did not benefit, is clearly in need of a renewed effort. However, in Africa the human resources and institutional infrastructure are notably weaker. Natural constraints in the form of variable climate, soils of low fertility, limited water resources and lack of crop varieties specifically adapted to these variable conditions also pose challenges which are fundamentally different from those encountered during the first green revolution but which can be overcome. Thus, the experience of the first green revolution is unlikely to serve as a pattern for the next one.
4.39 Success will depend much more on better use and management of social and natural capital (i.e. human resources, natural resources and agro-ecosystems), accompanied by the enabling mechanisms that allow the concerns of the poorer farmer, herder or agricultural producer to be the focus of the new green revolution. The classical ingredients of plant and animal breeding, fertilizer and irrigation will be essential, but they alone do not hold the key to success.
5.1 As noted above, there is an abundance of technical options to make food production more efficient and higher yielding on approximately the same land area currently in use. Even though all the techniques are not fully researched and ready for extension, people should be able to continue to feed themselves provided that there is a rapid spread and adoption of best working practices and that other enabling conditions for sustainable food production are fulfilled. Three key elements in achieving this are efficiency of resource use, planning and implementation frameworks, and good governance.
5.2 Efficiency of resource use is the conversion of scarce resources (natural, social and financial) into useful products and services in a way that is economically viable but that minimizes the impact on the environment. However, the introduction of more sustainable, environmentally sound agriculture will not advance evenly; food production will still involve negative environmental impacts for the foreseeable future. Thus, future strategies must have a dual objective: to accommodate long-term transformation of food production into sustainable and environmentally sound resource use; and to mitigate any harmful short-term effects.
5.3 Although there is a scientific foundation for the belief that food production can keep pace with projected population growth and be environmentally sound, the aggregate picture is clearly misleading. Many areas where marginal land is farmed today are also those where population pressure, poverty and food insecurity are intense. These areas are usually difficult to reach and lacking in infrastructure and investment capital as well as in technical expertise. They are usually not endowed with the necessary resources for the production of market commodities and are therefore frequently excluded from food production initiatives. Governments have a special role to play in assisting and promoting rational development in these areas.
5.4 Appropriate planning and implementation frameworks are required to facilitate and diffuse science and technology and to put policy into action. In some countries this will require diversification through creation of employment in other economic sectors, more efficient transportation infrastructure and the removal of obstacles that impede efficient market mechanisms. In other cases, income and employment opportunities should be promoted within the agricultural sector itself, in areas such as processing, marketing(4) and support services.
5.5 Environmental conservation and enhancement plans are essential to building a lasting national food security system. In addition to the usual elements of conserving land, water and biological diversity and controlling pollution, such plans should be integrated with efforts to reduce the loss of high-potential arable land to other uses, to improve food security and to use an AEZ approach in planning processes in order to assess population-supporting capacity, so that national investment in food and agriculture can be directed most efficiently.
5.6 The environmental price of food production is usually found in the loss of natural vegetation and biological diversity, soil erosion and surface and groundwater depletion. Inevitably, there are divergent views about how land should be used, whether for industrial crops, food, nature conservation or industry. These conflicts exist for coastal and inland areas and common property resources (e.g. forests, grazing lands, oceans and seas). Thus, clearly defined procedures are required to resolve different needs and interests in society, not only of current generations but also taking into account future needs. This means involving the stakeholders (farmers, local land managers, NGOs, government, consumers and others) and evaluating the environmental costs of different land-use options.
5.7 Democratic structures and public opinion on environmental issues help to identify preferences and set appropriate land-use goals, taking into account the need for access to food and for an adequate diet for a healthy, active life. Transformation of current and future food production systems requires a land- or resource-use planning approach and the formulation of explicit goals for alternative land uses. Planning is also necessary to define incentives for sustainable use and to promote changes of attitudes and values for improved land-use options. The severe pressure currently on marine fish stocks is an example of how misguided policy and lack of planning can lead to indiscriminate use of a common natural resource.
5.8 Market forces seldom respond well to environmental problems unless encouraged or directed by government policy. Table 4 suggests, by region, some key areas where environmental performance is already strong or could be improved. It could also serve as a general reference for countries to evaluate their own environmental impacts arising from food production in order to set priorities and allocate resources.
5.9 The political and administrative framework within which food production can increase without leading to widespread environmental damage should have at least four main elements:
Table 4: Major focus areas for controlling environmental impact, by region
5.10 Experience has shown that countries in which there is good governance reap the benefits through more stable and sustainable economic growth. Good governance involves promoting dialogue with diverse interest groups and sharing decision-making authority and control over allocation of resources to district and local levels, while simultaneously discouraging corrupt or inefficient practices. A more enlightened role for government also implies working side by side with NGOs, farmers’ associations and the private sector. The marginalization of women from decisions and resources also has numerous negative effects on food production. Government is in the best position to assist in sensitizing women to environmental concerns by promoting interventions that improve their access to, inter alia, education and training, energy resources and credit.
5.11 A number of governments must undertake the complex and difficult tasks of land-tenure reform, channelling investment towards rural areas and enacting supporting policies that reflect a national ethic of sustainable development, reflecting, in turn, their circumstances.
5.12 Present definitions of economic viability primarily consider productivity and profitability; they do not take into account sustainability. Neither are the costs of harmful effects on the environment included in the system of national accounts whereby countries attempt to measure their net economic gains and losses. The loss of environmental goods and services is particularly detrimental to poorer countries whose economies are more dependent on natural resources and are thus more vulnerable to their loss. Intensive effort is needed to strengthen and test methodologies for national environmental accounting, which includes pricing the costs of soil and water degradation, depletion of plant nutrients, loss of forest cover and biological diversity, and practices that are economically and environmentally unsustainable
5.13 It is also necessary to calculate the environmental costs of producing different crops (i.e. the potential pollution or resource-degradation intensity) in order to understand the conditions required for successful production. For example, in South Africa agricultural income accounts have been adjusted to allow for various kinds of environmental damage such as soil erosion, crusting, compaction, acidity, salinization and loss of plant nutrients that arise from food production.
5.14 For economic, political, food-security or other reasons, many countries will continue to promote policies that are expedient in the short term but eventually become environmentally degrading and contribute little to sustainable economic development. Whereas regulatory (command and control) structures often create new problems, fiscal measures to promote environment-friendly techniques and economic incentives have been found to be cost-effective in correcting policy and market failures. These measures include charges for the destructive use of natural resources (e.g. farming on steep slopes, destruction of hedgerows or windbreaks) or for emissions, based on the costs of meeting agreed target concentra.tions (the “polluter pays” principle). Change may also be accomplished by carrot-and-stick methods which offer rewards or penalties proportional to the environmental damage avoided or caused.
5.15 In the short term, the replacement of command and control regulations by economic instruments is not practical for all environmental problems. It is necessary to begin the process by addressing the highest-priority problems first.
5.16 There is strong evidence that farmers rapidly adopt innovations if they are found to be beneficial. Thus, a challenge to the national and international research community is to design innovations and incentives that are economically rewarding to individual producers as well as being environmentally sound. IPM and IPNS packages work on this basis, but continuous interaction of farmers, extension workers and scientists is required to raise awareness and obtain consensus among the parties concerned.
5.17 A number of actions can help promote environmentally sound production methods and change land-use practices:
5.18 Efficient use of data and information can be critical in avoiding and mitigating harmful environmental effects, but gaps and poor accessibility are major constraints. In addition to the absence of important data and information, there are many examples where existing data are not used because they are not shared, users are unaware that they exist, or they are not organized in a manner that easily allows analysis.
5.19 In the past ten years, environmental impact assessment (EIA) has become an important planning and analysis tool for the rural sector. Most of the multilateral development banks and many countries screen projects to determine whether significant negative effects are likely and whether an EIA should be required. Nonetheless, there remains considerable need to:
5.20 Despite decades of development assistance, there is still a regrettable lack of systematically collected data on land cover, land use, land degradation, water availability, biological diversity and important social and legal dimensions of food production. This situation is being partly addressed through a collaborative effort between the World Bank, FAO, the United Nations Environment Programme (UNEP) and the United Nations Development Programme (UNDP) to develop land-quality indicators (LQI) which will assist countries in organizing their existing data and information and identifying key indicators for monitoring a wide range of land-related issues. Countries will identify key land-quality problems, set policy goals and monitor progress on issues such as soil erosion, fertility decline, decrease in natural biological diversity, food insecurity and rural unemployment. There is also a strong need for new data collection, but the needed resources are seldom allocated.
5.21 Steps are already under way between FAO, the United Nations Educational, Scientific and Cultural Organization (UNESCO), UNEP, the World Meteorological Organization (WMO) and the International Council of Scientific Unions (ICSU) to monitor long-term global changes in land cover and land use through the establishment of a global terrestrial observation system (GTOS), to observe changes in natural and agricultural systems using remote sensing and ground measures. GTOS will gather information on land-use change, land degradation, the sustainability of managed ecosystems, water-resources management, pollution and toxicity and loss of biological diversity, and it will complement global observation systems for climate and the oceans (GCOS and GOOS).
5.22 The past two decades have seen the role of government reduced in favour of greater responsibility of the individual and the marketplace. The arguments have been that governments should limit their interventions to the optimization of the public good (e.g. environmental protection, food security) and that they should decouple income transfers from incentives or disincentives for resource allocation and production. Government interventions have often led to environmental problems. In some developed countries, agricultural subsidies have encouraged intensification that has been costly and counterproductive; in developing countries, prices for farm inputs have been kept artificially low. In these cases, the effect has been to encourage producers to specialize in certain crops and to intensify their use of inputs, contributing to soil and water degradation and other types of environmental mismanagement.
5.23 A general principle should be to reduce government intervention to the extent that significant environmental impact from pollution and degradation does not occur, while at the same time allowing the private sector to take the initiative in promoting efficient and productive agriculture.
5.24 Trade in food commodities will continue to play an important role in national economies throughout the world, but environmental and health safety standards will also continue to grow in importance. In view of the difficulty of applying the same standards to all countries, some concerns have been expressed about their effect on the agricultural competitiveness of countries that have high standards. At the same time, developing countries are concerned about the impact of the use of trade measures based on environmental standards to limit their market access. This topic is currently being debated in international fora in order to reconcile such potential conflicts, but it will probably remain a point of contention for the foreseeable future.
5.25 Continued efforts are needed to conserve natural ecosystems that provide the habitat for wild plant and animal species that are potential sources of future food, pharmaceuticals or other products. Adequate management measures are required to protect the wild relatives of crop species and wild food plants in protected and other areas. Increased efforts are also needed for on-farm conservation of landraces or traditional crop varieties and should be reflected in agricultural development strategies. In marginal areas, where many small-scale farmers live, strengthening on-farm plant genetic resources management and improving landraces through breeding are effective strategies both for improving the livelihoods of farmers and for preventing land degradation.
5.26 In addition, energy availability must be accepted as a pivotal constraint on achieving food security and environmental protection, because of its central role in increasing efficiency of labour and diversifying the range of economic activities that are possible in rural areas. Countries that rely on wood energy for food processing and preparation should allocate a portion of their land area to fuel production. They should, similarly, examine opportunities for growing biomass, specifically for its energy value, and for bringing marginal and/or degraded lands back into production through biofuel initiatives. More importantly, agricultural authorities must work more closely with their counterparts in energy to increase the availability of both conventional and renewable sources of energy in rural areas. This alone would provide a powerful incentive to rural people to remain and manage their natural resources more efficiently, as well as to expand the range of economic activities in which they engage.
5.27 The ways in which governments can work with the private sector and with NGOs to increase the quantity and quality of food include:
5.28 With regard to poverty alleviation and food security, the inability to achieve environmentally sound and sustainable food production is primarily the result of human inaction and indifference rather than natural or social factors. Compounding the shorter-term problems of damage to soil, water, forests and fisheries are longer-term prospects of climate change, loss of biological diversity and the pressure of an increasing human population.
5.29 It is difficult to improve on what was enunciated in the den Bosch Declaration (FAO, 1991), which formulated the principles of sustainable agriculture and rural development. The declaration acknowledged:
“… the wide diversity of ecological, cultural, social and economic conditions under which agriculture is practised and recognised the primacy for agriculture to ensure first and foremost food security for all, both in terms of quantity and quality of food, to provide employment, and to improve livelihoods and security of income in rural areas”.
5.30 UNCED (1992) elaborated on the concept of SARD when in Agenda 21 it called for:
“...major adjustments in agricultural, environmental and macroeconomic policy at both the national and international levels, in developed as well as developing countries, to create the conditions for sustainable agriculture and rural development (SARD). The major objective is to increase food production in a sustainable way and enhance food security. This is best accomplished through education initiatives, utilisation of economic incentives and the development of appropriate and new technologies, thus ensuring stable supplies of nutritionally adequate food, access to those supplies by vulnerable groups, and production for markets; employment and income generation to alleviate poverty; and natural resource management and environmental protection. ...The priority must be on maintaining and improving the capacity of the higher potential agricultural lands to support an expanding population. However, conserving and rehabilitating the natural resources on lower potential lands in order to maintain sustainable man/land ratios is also necessary”.
5.31 It would be wrong for any reader of this paper to finish with the impression that the environmental problems and challenges faced in agriculture cannot be solved. In terms of biological potential and technology there is capacity to spare for producing enough food to meet demand, but those people who face chronic food insecurity clearly have immediate food needs that must be met. It would be equally wrong to think that the challenges can be overcome using the same approaches that have been used over the past 40 years; the nature of development must change. The framework for the change, Agenda 21, was adopted by the more than 160 heads of State who attended UNCED.
5.32 National governments, in partnership with intergovernmental agencies, NGOs and the private sector, must commit themselves to strategies that are based on realistic estimates of production potential and population-supporting capacity. These must be balanced against national development priorities and, for the most part, developed, initiated and managed by the people who will feel their effects. It is short-sighted to ignore environmental issues, as this penalizes future development and the quality of life of the people who most need the food.
5.33 The important message that must go out to all countries is that participation, equity, dialogue, enabling mechanisms, empowerment and incentives will be the pathways towards environmentally sound agriculture and food security. Without them, the important technology and policy tools that are available will not have lasting positive effects.
Altieri, M.A. 1994. Biological diversity and pest management in agro-ecosystems. Binghamton, UK, Hayworth Press.
Blaikie, P. & Brookfield, H. 1987. Land degradation and society. London, UK, Methuen & Co.
Borlaug, N. & Dowswell, C. 1996. The acid lands: one of agriculture’s last frontiers. Keynote lecture, 4th International Symposium on Plant-Soil Interactions at Low pH. Belo Horizonte, Brazil, 17-24 March.
Breth, S.A., ed. 1996. Integration of sustainable agriculture and rural development issues in agricultural policy. Proceedings of the FAO/Winrock International Workshop on Integration of SARD Issues in Agricul.tural Policy. Morrilton, AR, USA, Winrock International.
Brown, L.R., Lenssen, N. & Kane, H. 1995. Vital signs: the trends that are shaping our future. London, UK, Worldwatch Institute, Earthscan Publications.
Consultative Group on International Agricultural Research, Technical Advisory Committee (GCIAR/tac). 1994. Review of CGIAR priorities and strategies. Rome.
FAO. 1990. International code of conduct on the distribution and use of pesticides (amended version). Rome.
FAO. 1991. The den Bosch Declaration and agenda for action on sustainable agriculture and rural development. Report of the FAO/Netherlands Conference on Agriculture and the Environment, ’s-Hertogenbosch, the Netherlands, April 1991. Rome.
FAO. 1993a. World soil resources. World Soil Resources Report No. 66, Rev. 1. Rome.
FAO. 1993b. Rural poverty alleviation: policies and trends. FAO Economic and Social Development Paper No. 113. Rome.
FAO. 1993c. 1993 Country tables: basic data on the agricultural sector. Rome.
FAO. 1994a. Assessing the contribution of high potential areas in developing countries to improving food security on a sustainable basis. Committee on World Food Security, 19th session. Rome.
FAO. 1994b. Bioenergy for development. FAO Environment and Energy Paper No. 13. Rome.
FAO. 1994c. Sustainable agriculture and rural development: new directions for agriculture, forestry and fisheries. Rome.
FAO. 1995a. World agriculture: towards 2010. N. Alexandratos, ed. Rome, FAO, and Chichester, UK, John Wiley.
FAO. 1995b. Planning for sustainable use of land resources: towards a new approach. Land and Water Bulletin No. 2. Rome.
FAO. 1995c. Covenant on the effective management of plant nutrients, by R. Dudal. Rome. (Draft)
FAO. 1995d. The state of food and agriculture 1995. Rome.
FAO. 1996a. Training for agriculture and rural development 1995-96. Economic and Social Development Series No. 54. Rome.
FAO. 1996b. Preliminary results and conclusions on population distribution in relation to agro-ecological zones, by F.O. Nachtergaele, L.J.M. Jansen & M. Zanetti. Working paper, Soil Resources Management and Conservation Service, Land and Water Development Division. Rome. (Draft)
FAO/World Bank. 1996. Livestock and the environment: finding a balance. Rome. (Final draft)
Garrett, J.A. 1995. A 2020 vision for food, agriculture and environment in Latin America. Washington, DC, USA, international Food Policy Research Institute (IFPRI).
Griffon, M. & Weber, J. 1995. Economic and institutional aspects of the doubly green revolution. Paper presented at the international seminar Towards a Doubly Green Revolution, Poitiers, France, 8-9 November.
Hoogerbrugge, I.D. & Fresco, L.O. 1993. Home garden systems: agricultural characteristics and chal.lenges. Gatekeeper Series No. 39. London, UK, International Institute for Environment and Development (IIED).
International Food Policy Research Institute (IFPRI). 1995. A 2020 vision for food, agriculture and the environment: the vision, challenge, and recommended action. Washington, DC, USA.
Janssen, B.H. 1993. Integrated nutrient management: the use of organic and mineral fertilizers. In H. van Reuler & W.H. Prins, eds. The role of plant nutrients for sustainable food crop production in inter-tropical regions. Leidschendam, the Netherlands, Dutch Association of Fertilizer Producers (VKP).
Lal, R. 1994. Sustainable land
use systems and soil resilience. In D.J. Greenland
& I.
Szabolcs, eds. Soil resilience and sustainable land
use, p. 41-68. Wallingford, UK, CAB International.
Munasinghe, M. & Cruz,W. 1995. Economy-wide policies and the environment: lessons from experience. World Bank Environment Paper No. 10. Washington, DC, USA, World Bank.
Oldeman, L.R., Hakkeling, R.T.A. & Sombroek, R.G. 1990. World map of the status of human-induced soil degradation. Wageningen, the Netherlands, International Soil Reference and Information Centre (ISRIC) and Nairobi, Kenya, United Nations Environment Programme (UNEP).
Pretty, J.N. 1995. Integrated crop nutrition for sustainable agriculture: technology and policy challenges. Joint IFPRI/FAO Workshop on Plant Nutrition Management, Food Security, Sustainable Agriculture and Poverty Alleviation in the Developing World from Now to 2020. Viterbo, Italy, 16-17 May.
Reardon, T. & Vosti, S.A. 1995. Links between rural poverty and environment in developing countries: asset categories and investment poverty. World Dev., 23: 1495-1506.
Smaling, E.M.A., Fresco, L.O. & de Jager, A. 1996. Classifying, monitoring and improving soil nutrient stocks and flows in African agriculture. AMBIO. (In press)
Tschirley, J.B. 1996. Considerations and constraints in the use of indicators in sustainable agriculture and rural development. Paper presented at the FAO Workshop on Land Quality Indicators, Rome, 25-26 January.
United Nations Conference on Environment and Development (UNCED). 1992. Agenda 21: Programme of action for sustainable development. New York, United Nations.
United Nations Environment Programme (UNEP). 1995. The environment and rural development: towards ecologically and socially sustainable development in rural areas. 23rd meeting of the ACC Subcommittee on Rural Development, Paris, France, 31 May - 2 June.
UNEP/International Soil Reference and Information Centre (ISRIC). 1991. The global assessment of human-induced land degradation (GLASOD). Wageningen, the Netherlands and Nairobi, Kenya.
Watson, R.T., Haywood, V.H., Baste, I., Dias, B., Gámez, R., Hanetos, T., Reid, W. & Ruark, G. 1995. Global biological diversity assessment: summary for policy-makers. Cambridge, UK, UNEP.
World Bank. 1995. Monitoring environmental progress: a report on work in progress. Environmentally Sustainable Development Series. Washington, DC, USA.
World Commission on Environment and Development. 1987. Our common future. Oxford, UK, and New York, NY, USA, Oxford University Press.
Major agro-climatic zones
Source: FAO, IIASA, ISRIC. Projection Miller, April 1995.
severity of land degradation in the major agro-ecological zones of africa, 1996
Source: ISRIC, FAO, ISSA. Projection Miller, February 1996. Computations by J.W. Resink and M.H.C.W. Starren.
Estimated agricultural productivity classes, in grain equivalents, 1995
Potential agricultural
productivity classes, under a high input level
with
limited water availability, in grain equivalents
Estimated yield gap, in grain
equivalents, under a high input level
with limited water
availability
Source: FAO, IIASA, ISRIC. Projection Miller cylindrical, April 1996. Computations by J.W. Resink and M.H.C.W. Starren.
(1)
See also WFS companion paper 3 Socio-political and
economic environment for food security. Back to text
(2) See also WFS companion paper 12 Food and international trade. Bact to text
(3)
See WFS companion paper 6 Lessons from the green
revolution: towards a new green revolution. Back to text
(4)) See also WFS companion paper 8 Food for consumers: marketing, processing and distribution. Back to text
