Research and technology Knowledge

Posted July 1996

Plant production


Science and technology for sustainable development, Part 8

Introduction

Part 1
Forest management and conservation

Part 2
Land and water development

Part 3
Protecting fisheries resources

Part 4
Plant protection and pesticides

Part 5
Sustaining small farm enterprises

Part 6
Post-harvest technology and food quality

Part 7
Aquaculture

Part 8
Plant production

A few cereals provide the staple food for the majority of people in the developing regions. Rice, wheat and maize supply globally more than 50 percent of human calorie requirements. Other cereal crops that figure strongly in the diet of people in particular developing regions are barley, sorghum and millet.

Roots and tubers are also important staples. They supply up to 20 percent of the calories in the diets of people in wetter tropical regions. Some are relatively drought resistant, and may therefore also be important in less humid climates. Cassava (manioc) is an example of this group of crops. Food legumes and some oilseeds supply protein to round out the diet, and vegetables and fruit are major sources of the minerals and vitamins people need for a healthy, active life.

For most developing countries, food crop production and the harvesting, storage, handling and shipping, processing, trading and marketing of foods, food products and other products from plants are the major source of both food and employment. Often agricultural crops and products earn a share of the foreign exchange used by the nation for its development. Additionally, grass and forage crops, and crop by-products yield much of the feed needed for livestock production.

On a world basis the application of science and technology has driven food production to levels unimaginable even 50 years ago. Breakthroughs in production, however, have only been realized in some crops and in some ecologies. Food shortages are still prevalent in many regions of the world. Much remains to be done to increase food production in developing countries. Cropping practices capable of sustainable production need to be elaborated, especially for fragile ecologies such as those found in tropical high rainfall zones and also in the savannah of West Africa, which could potentially become the breadbasket of the region's densely populated countries.

Science and technology help FAO to assist its member nations to increase food production. Typical applications include the conservation, improvement and use of genetic resources; crop management and diversification; diffusion of improved varieties; adaptation of production techniques to local conditions, development of a cropping systems and low-risk technologies for rainfed agriculture; sustainable cropping systems for areas prone to environmental degradation; use of agroecological data for crop production forecasting; and networks for regional coordination, data exchange and technical cooperation. New technology is important to the growth of agriculture. FAO therefore promotes technology generation and technology transfer so that, ultimately, farmers can be more productive.

Plant genetic resources

The genetic diversity shown in the plant kingdom is indispensable for improving agricultural production. This diversity also serves as insurance, as a buffer, against harmful environmental changes. Its role in sustainable development in agriculture and forestry as well as in environmental conservation and stability cannot be over-emphasized. The conservation of genetic diversity is an investment for and moral obligation to future generations of people. Concern over the loss of plant genetic resources for agriculture has increased in recent years because the threat of destruction of natural biotypes is growing and the existing genetic diversity is being eroded. The necessary intensification of agriculture with widespread cultivation of improved varieties is thought to be one of many factors that can lead to loss of genetic diversity. To counter this threat, since 1983 FAO has been developing a global system for safeguarding and utilizing plant genetic resources. This system consists of:

The International Undertaking, the Commission and the Fund for Plant Genetic Resources aim to ensure the conservation, sustainable use and unrestricted availability of the germplasm of useful plants and of sources of genetic diversity or special characteristics. Necessary scientific and technical activities are the description and classification of genetic material; construction, operation and maintenance of gene or seed banks; and genetic evaluation of plant material in base and working collections for use in plant breeding and in adaptation leading to introduction of improved varieties in farmers' fields.

Many of these activities were developed and are implemented by FAO in cooperation with the International Plant Genetic Resources Institute (IPGRI), a centre of the CGIAR. FAO is establishing a worldwide information system on plant genetic resources. This will have a component to give early warning of serious threats to genetic diversity. A periodic report of the state of knowledge on plant genetic resources is to be issued. The FAO Conference has adopted a Code of Conduct for Germplasm Collection and Transfer, and a Code of Conduct on Biotechnology as it affects the conservation and use of plant genetic resources is being developed. FAO is also seeking to establish an international network of ex situ base collections.

New and improved varieties and agricultural practices

The development and use of improved varieties will continue to provide the farmer with one of the most easily adopted and cost-effective innovations. Great advances have been made in the yields of the world's most important staple food crops, but further improvement is possible. In particular, improved varieties and other technologies are needed that fit specific production locations and socio-economic conditions more fully. Other contributions will also be important: resistance to pests and diseases, the improvement of quality, and the adaptation of the crop to more efficient production practices, such as mechanized seeding and harvesting. For small-scale farming under difficult conditions, adaptation to low input/low soil fertility levels is a core criterion for varietal development.

Crop improvement has always been central to FAO's food security strategy for developing countries. Hybrid maize trials began in the late 1940s. In the early 1950s FAO had a major role in the creation of the International Rice Commission. The Commission's support to a breeding programme using the variety “Mashuri”with intercrossed Japonica x Indica rice led to an improved variety that is still cultivated by farmers. In 1952 wheat and barley breeding projects were launched in the Near East. The 1960s saw increasing efforts to enable the transfer of tree and other crops formerly grown on plantations to small-farm operations.

FAO, as a sponsor of the CGIAR, supports varietal improvement and other research done at the International Agricultural Research Centres on major field food crops and is constantly exploring mechanisms to assist in the transfer of new technology from these centres to national research programmes. Such activities are expanding with increase in collaborative projects, training of staff of national research institutions and support to strengthen national and local research capacity.

Many FAO projects are designed to help national researchers develop better varieties and management practices so as to overcome constraints such as pests, diseases, drought and soil acidity that limit productivity in the specific ecologies where the crops are grown. These are continuing and recurring problems that must constantly be attacked locally by better science to find and apply effective technology. FAO also assists national researchers in their efforts to verify that research findings obtained under experimental conditions can be reproduced as closely as possible on the farm, to transfer proven technology to the farmers, and to ensure that scientists have a fuller or more accurate view of the constraints faced by farmers.

In the tropics the management of crop agriculture to sustain the agroecosystem without degradation is a major need now and for the future. One way to attain sustainability is by deliberate integration of woody perennials in crop or livestock production systems in a manner that suits local conditions and is profitable for smallholders. Several FAO projects are exploring the merit of such systems in which agroforestry has a role.

Microscopically small forms of plant life can also be harnessed to improve crop management. In rice production systems, the incorporation of blue-green algae or of Azolla can provide weed control, biologically fixed nitrogen from the atmosphere, organic matter, malaria control, and livestock feed (30 percent protein). FAO is promoting applied research on Azolla technology and its use in suitable ecologies, as well as on Sesbania, a woody plant with symbiotic nitrogen fixing capacity that can serve as green manure for crop production.

Modern biotechnology offers solutions to some old problems, especially the elimination from planting material of viruses that cause extensive losses in crop production. Biotechnology may in future defend crops against insect pests, help in breeding stress-tolerant varieties, and fix hybrid vigour in crops such as maize so that millions of small farmers will one day be able to save their own hybrid-derived seed for planting.

FAO organizes workshops, study tours and regional cooperation networks through which participating scientists can share ideas on how to solve difficult research problems and can promote technical cooperation among countries and institutions concerned with the development of agriculture in the Third World.

Seeds

The farmer uses plant genetic resources by way of seeds or vegetatively propagated planting materials. Seed is the bearer of hereditary traits and therefore essential for the continuity of the species. It is often the one input which the farmer can produce on his own farm. At the same time, seed is an excellent change agent, a tool for transfer of improved technology. The availability to farmers of quality seeds of superior varieties in adequate amounts at the right time and at fair prices is one of the most important contributions to modern agriculture.

FAO provides seed samples - more than one million since 1953 - and information on seed and sources of plants to national and international research centres, scientists and field projects. The samples are used for crop introduction, evaluation and breeding. FAO assistance includes projects for the production and use of good quality seed, training and guidance in the fields of crop plant micropropagation and multiplication, quality control, processing, storage, distribution and promotion of improved seed. Field trials and demonstrations help countries to develop the necessary technical information for their proper use and specifically for identifying new or improved varieties that are adapted to local conditions. FAO has set up a computerized seed information system to promote the collection and dissemination of information on:

The publication FAO Seed Review is issued at 5-year intervals. It gives information on seed-related activities in member countries.

Crop plant nutrition

Plant growth is made possible by energy and materials for photosynthesis. Soil serves both as a structural support and as the source of the moisture and nutrients that are absorbed through the plant roots. Proper plant nutrition depends on the availability of nutrients at the right time, in suitable quantity and in the needed form and balance.

Nutrients needed by virtually all crop plants are nitrogen (N), required in the greatest amount, and lesser amounts of phosphorus (P) and potassium (K). These elements are present in all soils in varying amounts. Good agricultural practices aim to compensate for deficits which arise from many causes, including continuous crop production without restoration of the nutrients removed in plant growth.

A good, well-nourished plant cover (leaves) with active photosynthesis and a well-developed root system help to maintain the proportion of oxygen in the atmosphere, use carbon dioxide in photosynthesis, reduce the risk of erosion, minimize surface run-off of water and reduce downward leaching of nutrients. Good plant nutrition, by stimulating plant growth, also increases the humus content of soil via an enlarged root system and increased litter fall.

Increasing use of marginal land and the pressure to extend cultivation to unsuitable areas such as shallow soils and steep slopes, together with inappropriate land use practices, has led to soil degradation, nutrient “mining”and declines in crop yields. Studies on larger-scale intensive cereal production have shown that an average yielding grain crop removes some 100-150 kilograms of major nutrients per hectare per year, and a 5-6 t/ha crop of rice or wheat removes up to 360 kg/ha. In addition, secondary nutrients, such as sulphur and micro-nutrients, only traces of which are required, are also lost.

Where supply of fuelwood is inadequate, animal manure is often used as fuel by small-scale farmers together with crop residues. By not returning organic material to the land, the soil's fertility and water-holding capacity decline, increasing the vulnerability of crops to drought and reducing the productivity of soil, crops, labour and energy.

Restoring soil fertility

In areas where shifting cultivation based on “slash and burn”is still practised and land can not be left fallow for long after cultivation, soil fertility is lost and must be made good. Loss of fertility also occurs wherever crops are produced continuously on the same piece of land, no matter how fertile the soil may be initially. Once soils are on the verge of degradation, crop production technologies that use minimum inputs are unlikely to prevent further degradation. Restoration of soil structure and fertility will require application of mineral fertilizers and/or large dressings of manure of plant or animal origin.

Thus sustained and ecologically sound farming will depend largely on the external provision of plant nutrients. Green manure from plants, animal manure and biological nitrogen fixation all have an important contribution to make, with mineral fertilizer covering the remaining deficit.

The use of mineral fertilizers in developing countries is limited by cost and availability to the farmer. These depend on local production capacity, availability on the international market, having the foreign exchange to purchase them, and subsequently on efficient distribution and marketing systems within the country. These systems, in turn, depend on adequate infrastructure such as roads, vehicles and warehouses, as well as on an adequately trained workforce. Current fertilizer production, consumption, trade and price data are published annually in the FAO Fertilizer Yearbook.

FAO activities in plant production

Plant nutrition

FAO's activities to improve crop plant nutrition started in the late 1950s with a call for increased use of fertilizers by Third World farmers. A Fertilizer Industry Advisory Panel, and later an FAO Fertilizer Industry Advisory Committee of Experts (FIAC) worked with FAO to improve fertilizer quality and give guidance on formulations and modes of application appropriate for different soils and climatic zones. An International Fertilizer Supply Scheme was created by FAO in 1974 at a time of severe shortages of fertilizer in developing countries. Using resources contributed by donors in cash and kind, the scheme has provided assistance to more than 60 developing countries.

To promote technology for sound use of fertilizer on small farms, FAO has assisted developing countries in: (i) conducting trials on farmers' fields including testing of local resources like rock phosphates; tailoring fertilizer recommendations for specific localities; (ii) making plot and block demonstrations on farmers' fields; (iii) training national research and extension staff; and (iv) improving the distribution, pricing and related policies of fertilizer and other inputs. Information from over 80,000 field demonstrations and trials in Africa, Asia and Latin America is held in a readily accessed data bank.

Efficient use of fertilizers requires often the incorporation in the formulation of secondary nutrients such as sulphur and micro-nutrients such as boron. FAO organized trials in countries of Asia and Africa have demonstrated spectacular crop responses to the application of secondary and trace micro-nutrients when included in balanced applications with major nutrients.

To support sustainable crop production that makes use of all available plant nutrients, FAO in recent years has elaborated an integrated plant nutrition system (IPNS) approach that is environmentally sound and socially and economically viable. The cropping system rather than an individual crop is the focus of attention in this approach. In addition to mineral fertilizers it envisages the use of locally available materials of plant or animal origin such as by-products of agricultural activities or, where such materials are not abundantly available, in situ production of green manures.

Alternative sources of organic materials which have considerable potential as plant nutrients for use in IPN systems are: quick growing leguminous shrubs grown as a part of the cropping system and incorporated into the soil as green manure; leguminous trees or shrubs grown in alley formation, their loppings being used as mulch materials or incorporated into the soil; nitrogen-fixing Azolla and blue-green algae; and forage legumes or food legumes, properly inoculated with nitrogen-fixing rhizobia, grown in rotations. To foster the development of biological nitrogen fixation, FAO assists in selecting the best available strains of Rhizobium and in arranging for supply of small-scale production units for their local production.

Field food crops

Research on most cereals of importance in agriculture continues at the international centres of the CGIAR and elsewhere. FAO activities focus on assessing available production technologies and on the transfer and local adaptation of proven technologies. For example, new hybrid rice technology appears to have exciting promise for hybrid seed production in countries where labour costs are low. The hybrids outyield other rices by 15 to 20 percent. FAO already has projects in several countries in Asia.

The use of improved plant varieties and production practices is still very limited in most African countries. In cooperation with national institutions FAO is using on-farm demonstrations to show farmers some of the possibilities to improve production. Among the improvements are suitable growing areas for different cereal crops, appropriate agronomic practices, and identification and field introduction of improved varieties. Special emphasis is given to demonstration of improvements in growing food legumes.

Compared with other field crops, yields of food legumes are frequently low in most developing countries. This is due to the limited introduction of improved varieties and the inadequate use of production inputs. Increased research on food legumes is needed to obtain improved technologies, as these crops have important roles in human nutrition and in the sustainability of agricultural production.

For some field food crops, such as perishable roots and tubers, increased production should be linked to increased capacity for postharvest processing and handling. Similarly, the potential of tropical soybeans as a protein and vegetable oil source can be best realized by coupling to village-level processing. FAO is developing projects that integrate processing, especially at rural level, with improved production techniques.

Root and tuber crops can be improved through the use of tissue culture techniques. The aim is to increase the genetic variation available for breeding work and to free germplasm and planting materials from virus infections which are extremely difficult to remove by other means. In collaboration with international research centres FAO promotes application of these techniques and of such other developments as the novel practice for production of some crops (e.g. potato, cassava) from true seed.

Other crops

Tissue culture techniques have also been used to good effect for the improvement of so-called industrial crops grown for fibre (cotton), edible oil (oilpalm), beverages (coffee, tea), sweetening (sugarcane), flavouring (spices) and medicinal use, and also for vegetables. For example, the use of tissue culture in sugarcane promises to almost double the sucrose content of the plant, thus releasing areas planted to this crop for production of other needed crops.

Tree crops, often grown in plantations, are sources of foreign exchange earnings for many developing countries. Such crops, and also spices, are important for smallholders as a source of income and to reduce risk through diversification of the farming system. FAO promotes science-based technology that allows more of the value added in the processing of such crops to remain in the rural areas. Equipment and techniques are adapted and demonstrated for village-level use, e.g. pressing of oilpalm kernels, extraction of essential oils from spices, and processing of a number of locally important tree crops.

FAO assists developing countries in the development of horticulture programmes aimed at supporting small farmers and rural communities. Such programmes have a wide range of objectives: to increase food security, improve consumption and nutrition, intensify production, improve income-earning capacity, and create opportunities for employment in production, processing and marketing of vegetables and fruit. Protected cultivation (greenhouse production of higher-value crops) offers considerable possibilities to improve productivity and quality and make better use of limited soil and water resources. The use of appropriate covering materials, climate control measures and integrated pest management (IPM) can increase yields substantially and provide better quality produce with low pesticide residues.

Most of the ruminant livestock production in the developing world has pastures, crop residues and fodder as its feed base. Ruminants are especially important in smallholder agriculture. Natural grazing lands still provide most of the feed used by ruminants. The availability of these lands is decreasing and their maintenance in a productive condition is often difficult or neglected because complex social issues of land tenure and grazing rights are involved.

FAO promotes recognition of the importance of grazing lands among the natural resources of developing countries. Such lands, which cover large areas of the earth's surface, have environmental value for all people as watersheds, wildlife habitats and recreational areas, and as a means for in situ conservation of genetic resources. These valuable uses should be taken into account in land-use policies and plans, and in the design of range management systems.

The development of grazing management systems suitable for the traditional livestock sector is a major preoccupation of FAO. Grazing does not always supply sufficient feed for sustained livestock growth. The cultivation of supplementary fodder is then necessary. In arid and semi-arid areas, fodder shrubs and trees (acacia) are frequently planted because of their better dry-season productivity and resilience in drought years. In very humid areas, grass production can be problematic and shrubs (Leucaena) are useful. FAO has advised and assisted with the selection of fodder species suiting particular ecological conditions.

The productivity of both the pasture and the animal is dependent on the available nitrogen supply. Where fertilizer nitrogen is expensive or unavailable in developing countries, the cultivation of legumes as a means of fixing atmospheric nitrogen symbiotically has long been encouraged by FAO. Providing facilities for production of nitrogen-fixing Rhizobium inoculant is part of this effort. FAO also promotes use of crop residues and by-products to supplement and diversify the feedstuff base.

SD Homepage Back to Top FAO Homepage