Agriculture, University of Peradeniya, Sri Lanka.1. INTRODUCTION
Most of the developing countries are dependent on agriculture for their economic as well as industrial development. In some of the Asia-Pacific countries, agriculture is the backbone of the economy and they are sensitive to changes in agricultural production, prices and other related policy options in the Region as well as in the global markets. Agriculture development will remain as the mainstay of the developing countries, in spite of the fact that most of them are moving towards industrialization. Therefore, the role of the agricultural sector in any developing country is focussed on food production, gainful employment, foreign exchange earnings, capital accumulation and labour replacement.
2. AGRICULTURAL LAND VS AGRICULTURAL POPULATION IN THE REGION
The total land area of countries in the Asia-Pacific Region vary widely, being highest in China (932.64 million ha) followed by Australia (768.2 million ha), India (297.3 million ha), Indonesia (181.1 million ha). Many small countries such as Bhutan, Fiji, Republic of Korea, and Sri Lanka have land areas below 10 million ha. Agricultural land as a percentage of total land has shown insignificant variation in the last decade. The average was 20.5 percent in 1988 and 21.0 in 1997; except in developed countries namely Australia, Japan and New Zealand, where some decline has been recorded. However, an interesting feature is the decline in the agricultural population to total population, which is common in the developing countries (66-62 percent) and also in the developed countries (7.6-4.9 percent) from 1988 - 1997. The agricultural population has shifted to the industrial sector not only in the Asia-Pacific Region but also in the whole world. The shift in the population from the agricultural to industrial sector focuses on two major issues on crop intensification in the Region. These are the high cost and the non-availability of labour even at any price during the cropping season. The high cost of labour has burdened agricultural production, particularly in the least developed nations, where labour cost alone account for over 50 percent of the total cost of crop production. The labour shortage is likely to continue, and its repercussion can be adverse unless crop production techniques are rapidly changed. The need for less labour intensive production technologies is emphasized.
The growth of population in the world has been rapid, intensifying the pressure on land. The total population in the Region has increased from 2.6 billion to 2.9 billion from 1988 to 1997. The largest populations are seen in this Region with China exceeding 1.2 billion and India (0.98 billion) which is on the verge of reaching the one billion mark. Of the 5.8 billion people in the world, about 50 percent of the people live in the Asia-Pacific Region. The growth of population is rapid, exceeding 3.5 percent in some countries. On the other hand, the size of an average holding is smallest in the Region, and the land to man ratio has declined rapidly over the years. The per capita agricultural land available in the Asia-Pacific Region in 1961 was 0.35 ha, which declined to 0.27 in 1988 and further reduced to 0.25 ha in 1997. A further decline in land availability is inevitable due to urban development and industrialization in many of those countries, leading to unprofitable units for crop production.
Crop production can be increased by increasing the extents of agricultural land, which as evident from the above becomes an impossible task. The other alternative is to bring additional land under cultivation by expanding into marginal lands in different countries, but these have been almost exhausted and even with heavy investment may remain marginal. Hence, of the available options, increase in intensity of cultivation and in yields per unit area are the only available options to meet future food needs to feed an ever increasing population.
Technologies continue to be developed in various countries that will have an impact on future crop production. Most of these technologies are directed towards increase in yield due to less land availability. In the future, therefore, increases in food production to enhance food and nutrition security have to be achieved through intensive cultivation and high yield and to a minor extent through increase in land areas. Over 75 percent of the high yield increases will arise from improvement of the yield of crops, with the balance from expansion of land area and cropping intensities.
In the future the potential for yield improvement will be through technological innovations. The potential yield increases are likely to be greater in the developing countries than in the developed countries. It could be argued that the yields in the developed countries have reached optimum levels due to the full exploitation of the available technologies, a “technology fatigue”, whereas the yields in the developing countries are always lower than the potential yield under experimental conditions. The yield gaps, which exist in most crops and the actual volumes at varying levels in different countries, point to the need for technologies which are less expensive. Estimates indicate that the yields, obtained in the less developed countries are about half to one third of those of the developed countries and even within the Region wide variations are observed. Therefore, there is much scope to increase the yield of crops.
There is a school of thought that the majority of small-scale farmers could be lifted out of poverty without the use of modern technologies such as improved seed, fertilizer and crop protection chemicals. They believe that soil fertility could be increased by organic manures, farmer bred and maintained indigenous varieties, biological or mechanical control of pests, diseases and weeds and human power to carry out farm operations. Although the low input sustainable agriculture (LISA) is getting popular in some industrialized countries its direct transfer to developing countries will have some resistance. With the present changes in the labour market and global trade, it cannot be applied and may not be relevant to the Asia-Pacific Region.
3. CONCEPT OF CROP DIVERSIFICATION
Crop diversification can be a useful means to increase crop output under different situations. Crop diversification can be approached in two ways. The main form and the commonly understood concept is the addition of more crops to the existing cropping system, which could be referred to as horizontal diversification. For instance, cultivation of field crops in rice fields or growing various types of other crops in uplands have been defined as crop diversification. However, this type of crop diversification means the broadening of the base of the system, simply by adding more crops to the existing cropping system utilizing techniques such as multiple cropping techniques coupled with other efficient management practices. The systems of multiple cropping have been able to increase food production potential to over 30 t/ha, with an increase of the cropping intensity by 400-500 percent. The other type of crop diversification is vertical crop diversification, in which various other downstream activities are undertaken. This could be illustrated by using any crop species, which could be refined to manufactured products, such as fruits, which are canned or manufactured into juices or syrups as the case may be. Vertical crop diversification will reflect the extent and stage of industrialization of the crop. It has to be noted that crop diversification takes into account the economic returns from different crops. This is very different to the concept of multiple cropping in which the cropping in a given piece of land in a given period is taken into account. Besides the above, some other terminologies are also used to define crop diversification. There are terms such as “crop substitution” and “crop adjustment”. It is necessary to indicate here that crop substitution and adjustment are linked to the main concept of crop diversification and are strategies often used to maximize profit of growing varieties of crops. The level of diversification will also be different in various countries. Diversification at farm level will involve growing of several crops for achieving self-sufficiency, but it may be a totally different approach at the national level. Crop diversification at national level will demand more resources and require selection and management of a specific crop or a group of crops sold freshly or value added to achieve higher profits.
There are several advantages of crop diversification, which could be listed as follows:
· Comparatively high net return from crops.In order to achieve the above benefits the process of diversification should be changed from very simple forms of crop rotations, to intensive systems such as relay cropping and intercropping or specialization by diversifying into various crops, where the output and processing etc., could be different. This process could be similar at farm level and national level.
· Higher net returns per unit of labour.
· Optimization of resource use.
· Higher land utilization efficiency.
· Increased job opportunities.
4. CROP INTENSIFICATION
As stated earlier, primary constraints to achieving food security are the low yield per unit area, high population pressure, and negligible scope for expansion of the area of land for cultivation. Under these circumstances available options will be crop intensification and diversification through the use of modern technologies, especially seeds, fertilizer, irrigation, mechanization of agricultural production, post-harvest processing, storage, marketing and development of new technologies by research.
4.1 Crop Nutrition
A major contribution towards increased yield and sustained production could be achieved by using fertilizers and manures. The actual usage of fertilizers is generally lower in the developing countries than in developed countries and dangers of overuse, as observed mostly in the highly industrialized countries, has not been a problem. Organic matter usage has been less in most countries, but its incorporation into the agricultural systems will make the soils fertile and less degradable. Several problems exist in the use of organic manures such as the volume required, time, labour and opportunity costs. Another recent development is in the development of crop rotations, a strategy towards diversification of agricultural systems to increase productivity and crop yields. This involves the insertion of green manure cover crops or other legumes in the cropping systems as seen in several countries. The popular crop mixes are legumes in maize and other cereals.
The consumption of fertilizers in terms of plant nutrients is a reliable indicator of nutrient usage by different countries in the Region. During 1973-1983 nutrient consumption increased from 17 to 35 million metric tonnes. During 1988-1997 further increases have been recorded from 47 to 63 million metric tonnes in developing countries of the Region, with an average annual growth rate of 3.7 percent. The countries using the highest rates of fertilizer nutrients were China (36 m Mt) and India (16 m Mt). The developed countries of the Region (Australia, Japan and New Zealand) also recorded average annual growth rates of 9.3 percent.
Although the rate of fertilizer used has increased, per hectare usage has been less impressive. Many of the developing countries use less than 20 kg nutrients per hectare and this is regarded as a major reason for low yields. In 1997, the highest rates of fertilizer/ha have been used by the Republic of Korea (471 kg/ha) followed by China (266 kg/ha), Vietnam (218 kg/ha) and Malaysia (158 kg/ha). Among the developed countries of the Region Japan has used the highest amount of nutrients (366 kg/ha) followed by New Zealand (211 kg/ha).
Further analysis of nutrient usage indicates that a large proportion of the fertilizer is used in rice cultivation and insignificant amounts for other field crops. It is necessary to increase the use of fertilizers and manures to ensure high crop responses to the applied nutrients. It is also necessary to encourage the use of organic fertilizers to renovate soils and improve their physical and chemical properties and biological activity. Slow release organic fertilizers are also used in some countries where about 80 percent of total nitrogen is present as organic nitrogen. At normal soil temperatures of around 27° C, about 60 percent of this nitrogen is released over the first four months. The losses due to leaching and volatilization will be less, hence the efficiency may exceed that of mineral fertilizers in the locations where these processes are likely to occur.
4.2 Agricultural Mechanization
Farm power includes human, animal and mechanical sources. In developing countries 80 percent of the farm power comes from humans. There is a trend for the shift of labour from agriculture to industry in most of the developing countries. This has already taken place in the developed countries. This would mean that the few remaining people in agriculture would be required to produce food for more and more people living in urban areas, showing 7 percent growth per year. Besides, labour costs are escalating, accounting for a high proportion of the cost of production. For instance in Sri Lanka, approximately 50 percent of the total cost in rice production is accounted for by labour. Sometimes, labour is not even available at any price during cropping seasons and lands are left fallow due to shortage of labour. On an average a farmer using his own labour could feed himself and three others, using draft power he can feed 6 persons and use of tractor could increase the number to over 50. Hence, it will be futile to believe that the regional food demand could be met by traditional farming systems. Therefore, mechanization will be an urgent need for all developing countries in the Asia-Pacific Region and benefits of machinery use are generally apparent.
The use of appropriate farm machinery in the production chain will make farming more efficient and enable farmers to diversify cropping by growing more crops. In many countries mechanization at various levels has lead to improved yields and high labourer productivity. It is reported that in China use of mechanization has led to 10 percent yield enhancement and 15 percent if irrigation is included. Use of machinery for harvesting and processing increases yield by simply reducing crop losses. The post-harvest losses in developing countries are reported as 20-40 percent. Saving this amount is equal to increasing the yield without any added costs. Use of agricultural machinery shows an upward trend in the Region. Agricultural tractors in use have increased from 2.2-3.3 million over the period 1977-1987 showing a growth rate of 4.2 percent. Some countries of the Region have developed local agricultural machinery manufacturing industries. Sri Lanka has made remarkable advancements in the commercial manufacture of water pumps, paddy, threshers, dryers, ploughs, puddle wheels, pruning shears, sprayers, milling machines etc., at prices affordable by the farming communities.
It is, therefore, necessary to make realistic assessment of the use of machinery in the agriculture sector with adequate government support to develop an agricultural machinery industry in the Region, to counteract the labour shortages during the growing seasons.
4.3 Irrigation
Water, which was considered a free resource in many countries, has suddenly become a scarce commodity and major threat to food production and food security. According to the International Water Management Institutes nearly 1.4 billion people, a quarter of the world population or a third of those living in developing countries, will face severe water scarcities in the first quarter of the century (Seckler, 1999). While the regional water consumption is increasing rapidly, the water supply is decreasing. The increasing demand for water has several components, while agriculture uses a large proportion of water, non-agricultural water uses are also increasing. Urbanization and higher per capita availability are the main reasons for increased water use. Per capita water availability is already declining rapidly. In Asia, water availability has decreased from 99,600 m3 in 1952 to 3,300 m3 in 1999. It is predicted that water availability for domestic and industrial use will increase in developing countries from 13 percent to 27 percent in 2020. When water is rationed industry and domestic supply are protected and agriculture will have to make the best out of what is left.
In the Asia-Pacific Region about 35 percent of the agricultural land is irrigated showing an increase of 6 percent from 1988 - 1997. The irrigated area as percentage of agricultural land in Pakistan is over 81 percent, DPR Korea 73 percent, Japan 63 percent, and the Republic of Korea 60 percent, while in the other countries the figures vary from 1.1 percent in Fiji to 1.4 percent in Bangladesh. The total agricultural land under irrigation has increased from 130 million ha to 158 million ha from 1988-1997. Large extents are in China (52 million ha), India (57 million ha) and Pakistan (17.6 million ha). In the other countries land under irrigation varies widely. There appears to be potential for further increases in irrigated land in most countries of the Region.
However due to the impending water scarcities in various countries some strategies and action plans may be required to alleviate any adverse situations. The following strategies could be used to overcome these problems:
· Ensure productive use of water in surplus areas for food production without being under-utilized owing to adequate food supplies.· Develop markets or international mechanisms for reallocation of food from surplus to deficit areas.The principle of micro-irrigation to deliver water to the root zone as the crop needs it, is no less valid for fertilizer. The combination of irrigation water with fertilizer, known as “fertigation” will be an obvious solution to get maximum benefits from their inputs while conserving the environment. Micro-irrigation will be an efficient tool to increase water use efficiency and its adoption is increasing. In Israel where these technologies have been perfected, the micro-irrigated area has increased from 10,000 ha in 1975 to 104,000 ha in 1999. FAO estimates that about 30,000 ha in the Near East Region or around 1.4 percent of the total area is under irrigation. In the Asia-Pacific Region also micro-irrigation is catching up. In Sri Lanka many crops such as banana, vegetables and other floriculture crops, coconut etc., are micro-irrigated. This method has many advantages: all nutrients are applied in soluble form and are readily available to the roots; absorption and precipitation processes in the soil are minimized, which is particularly important in the case of P and K; nutrients are placed in the active root zone increasing fertilizer use efficiency and reducing labour cost; and nutrient formula and ratio can be changed according to the crop. These changes can be made at different growth stages, and small doses at frequent intervals minimize osmotic stress in crops grown under saline conditions. Therefore, fertigation could economize on both water and nutrient use, and hence it can conserve natural resources and protect the environment.
· Reduce pollution of surface and ground water due to unscientific irrigation practices.
· Construct reservoirs for harvesting excess water especially in monsoonal regions.
· Conserve water by better irrigation management practices such as drip irrigation.
· Re-use and recycle waste water.
· Transfer water from surplus locations as already practiced in some countries of the Region.
There is significant scope for increasing food production through integration of water-based production and services. These include integrating aquaculture and fisheries, a concept referred to as the farming of aquatic organisms into agricultural development efforts.
4.4 Use of Improved Seed
Improved seed is one of the major contributors to crop diversification through development of appropriate cropping systems. The quality seed development at national level will be essential for yield improvement. The increase in annual yield of rice from 1.9 percent in the 1970's to 28 percent during the 1990's was attributed to use of improved seed coupled with better management practices. In most of the countries, estimated area planted to HYVs has increased as shown in Table 1.
Table 1. Estimated Areas planted to HYVs and Hybrid Rice (percentage of total rice areas) in Major Rice-Producing Countries of Asia
Country
|
1989
|
1997
| ||
HYVs1
|
Hybrid Rice2
|
HYVs
|
Hybrid Rice3
| |
| Bangladesh |
40.7
|
-
|
65.0
|
-
|
| India |
62.0
|
-
|
70.0
|
Neg
|
| Indonesia |
73.0
|
-
|
85.0
|
-
|
| Myanmar |
51.9
|
-
|
51.9
|
-
|
| Philippines |
88.5
|
-
|
93.0
|
-
|
| Sri Lanka |
90.0
|
-
|
95.0
|
-
|
| Vietnam |
-
|
-
|
85.0
|
Neg
|
| China |
-
|
50.0
|
45.0
|
50.0
|
1 IRRI, 19952 Yuan, 1996Among other cereals, the highest coverage under modern varieties is for wheat. It is estimated that more than 70 percent of the wheat acreage in major wheat producing countries (Bangladesh, China, India and Pakistan) is under improved varieties. In other crops, use of improved varieties is not extensive, but there is plenty of scope as farmers are quite responsive to the new varieties and have increasingly adopted them as and when they are released for cultivation.
3 FAO estimate (Neg = hybrid rice was planted to about 120,000 ha in India and about 180,000 ha in Vietnam)
4.5 Protected Agriculture
The most recent addition to crop diversification is the introduction of crop production under controlled environments. This concept known as protected agriculture has made rapid headway, becoming popular among middle income agriculturists. Protected agriculture or controlled environment agriculture is the modification of the natural environment to achieve optimum plant growth. In these systems various factors of the environment such as air, temperature, humidity, atmospheric gas composition, nutrient factors etc., are controlled. These technological developments coupled with use of high quality crop varieties are integrated into a system of agricultural production, which is referred to as protected agriculture.
The main forms of protected agriculture include the use of mulches, row covers and poly-tunnels. It has been a common practice to use organic mulches such as straw, dead leaves, coir dust etc., to modify the environment to make soil more favourable (weed and moisture control) for plant growth. However, in the recent past these low cost agronomic practices have received less attention from the farmers. Plastic mulches are also used for the production of high-value crops and pineapple plantations in Hawaii. Plastic mulches with drip irrigation are widely used as irrigation water and fertilizers (fertigation) could be applied together with the added advantage of reducing cost of production. Row covers have also been used since the 1950's. These are polyester sheets stretched over rows of plants as seen in tobacco nurseries. These also help to prevent crop damage by insects, sunlight and sometimes frost in cooler areas. These technologies are used with other related technologies, such as hydroponics and drip irrigation and these are the major areas of protected agriculture practiced in different countries. In Sri Lanka, poly-tunnels, drip irrigation and hydroponics are commonly practised and demonstrations have been established by the Department of Agriculture.
In most countries soil is the medium used to grow vegetables and other crops. When plants are grown in the soil several problems are encountered due to many soil borne diseases and pests. These problems increase the cost of production due to the use of pesticides and soil fumigants. This has lead to the use of hydroponics. Hydroponics culture/soil-less-culture is a means of growing plants in a nutrient medium without soil to support them. This method began around the 1930's on a commercial scale with research conducted on many aspects by the University of California, USA. Hydroponics culture will facilitate growing of plants in areas with marginal conditions for crop production, such as adverse climate, soil, disease and pest occurrences. The controlled system with soil-less-culture could be used to obtain high yields but requires good management skills for successful crop production.
Many benefits could be obtained by practicing controlled environment agriculture. Some of the major benefits could be summarized as follows:
The land available for agricultural production is continuously decreasing due to the development of industries, urbanization, housing projects etc. The per capita agricultural land in the Region at present is only 0.25 ha. Therefore, future food production will have to come through intensive cropping on small extents of land and crop production strategies may have to be changed. It is here that the protected agriculture has to be considered due its specific advantages in food production.
Labour is a major limitation in open field agriculture. As protected agriculture requires less labour, it could offset the initial high investment.
Excessive uses of inputs such as fertilizers and pesticides, frequent cultivation, and lack of proper erosion control systems are constant threats to the environment. As input use, particularly fertilizers and pesticides, is controlled in protected agriculture, not only will it be economical in terms of input use but also environmentally friendly and provide products of high quality free of pesticide residues for human consumption.
In drought prone areas, scarcity of water during periods of droughts, and irregular rainfall has been responsible for crop losses. Under controlled agriculture water use is controlled and is minimal. This will be a major advantage in introducing protected agriculture to dry regions.
The major advantage of protected agriculture is high crop yield compared with open field agriculture. These high yields are achieved through the provisions of optimum conditions such as balanced plant nutrition for plant growth, which the open field agricultural operations can never provide.
It is very essential to develop low cost poly-tunnels so that the system could be adopted by many entrepreneurs. The development of structures with locally fabricated material having sufficient durability should be undertaken to make the systems affordable to as many groups of the farming community as possible.
Another major issue is regarding the type of crops having a competitive advantage that could be grown. The diversification into selection of high-value crops that have markets both locally and overseas and those with high genetic potential for yield and quality will be essential for success. Today, some of the crops grown under controlled environments include: tomato, sweet corn, red, green and yellow bell peppers, strawberry, cauliflower, cucumbers, cantaloupe, lettuce, green peas and ornamentals/cut flowers. To achieve maximum benefit these systems will require easy access to good seed, preferably hybrid seeds, which are commonly used in advanced countries. There is a need to study the feasibility of developing hybrid seeds as imports will be costly and non-affordable by the farmers as they will have to be replenished every season.
Standard methodologies should be developed for crop selection, raising seedlings, production methods, irrigation/fertilizer application, pest control (particularly IPM), which could be used in these high-tech systems. Research and development will be required to refine existing technologies as appropriate to different ecological regions of different countries.
The main markets for protected agricultural products are the super markets, airline caterers, hotel industry and exports to a limited extent. There should be market intelligence, which should be provided to the growers, processors and exporters to encourage and maximize profits.
4.6 Organic Farming
Organic farming includes all types of agricultural production systems, which are environmentally, socially, and economically sound. It has been defined differently by several workers, but all of them lay much emphasis on soil and environment conservation. It is also different to traditional farming in that it involves a holistic approach to sustainable agriculture. This form of crop diversification has spread on the continent, particularly in Germany, Switzerland, Austria, Denmark, Sweden and Finland and is spreading into the Asian and African continents. The demand for organically grown food is gaining momentum all over the world. The USA market volume for organic produce is in the region of 5 billion US Dollars. It is also increasing in developing countries. The question often asked is whether organic farming could feed the rapidly growing world population? This is debatable; but even with the “Green Revolution” with plentiful use of chemical fertilizers, over 800 million people of the world are starving and many may die of hunger.
4.7 Role of the Farming Community
In crop diversification towards sustainability, far greater emphasis should be given to farmer participation in adopting and implementing new technologies. It is also necessary to combine farmers' traditional knowledge with the contribution of sciences, solicited in a way that addresses their needs, values and objectives. Crop diversification strategies have failed in most cases due to ignorance of farmer involvement and external and internal factors that effect the system. One of the major issues is also crop selection. In rice-based crop diversification, crop selection does not pose a severe problem as it depends on the soil type. In upland crop diversification, crop selection and management depends on market values and past experience. A sustainable programme of diversification could be achieved only through farmer participation in the planning process. According to Marambe et. al. (1999) for crop diversification in minor irrigation schemes in Sri Lanka, the major factors are the decisions made on selection of crops and efficiency of resource allocation and utilization.
4.8 New Technology Development
Asian Agriculture has benefited from innovative front line research during the past two decades. Rapid progress has been made in cereal production due to the development of high yielding varieties of rice, wheat and maize. Cereal breeding, including the production of hybrids, is continuing which will enhance crop production in the Region.
Modern biotechnology in which characteristics based on single genes can be transferred from any organism to plants has resulted in transgenic plants combining disease or insect or herbicide tolerance. Therefore, the emerging genetic technologies could be beneficial to farmers due to their cost effectiveness. On a global level, transgenic crops increased from 2.8 to 12.8 million ha from 1996 to 1997. The industrialized countries grow large extents (75 percent) while developing countries (especially China in the Region) grow only 25 percent. The use of transgenic crops has come under severe scrutiny in recent times and some countries have completely banned their import until the actual situation is clarified.
The development and utilization of new technologies have to be supported at the national level, both in terms of capacity building with appropriate training, and policies programmes, and mechanisms for their implementation. Increased resources for agricultural research and development are essential so that conventional and biotechnological applications can be accelerated and integrated to produce high yielding crops and safer foods. It is now widely acknowledged that conventional technologies will be less than adequate to double food production, and biotechnology will be an essential strategy to achieve food security in the Region.
REFERENCES
IRRI. 1995. World Rice Statistics. 1993-94. Los Banos, Philippines
Yuan, L.P. 1996. Hybrid rice in China. In Hybrid rice technology, Directorate of Rice Research, Hyderabad, India 51-54.
Marambe B, Sangakkara, U.R. and Azharul Haq, K. 1996.. Crop Diversification Strategies for Minor Irrigation Schemes. Proceedings of Workshop, 20 Feb. 1966, IMMI, Sri Lanka.
Seckler, D. 1999. Water scarcity and challenge of increasing water use efficiency and productivity. Sustainable Agriculture Solutions. Novello Press, London, 116-126.
For further details log on website :
http://www.fao.org/docrep/003/x6906e/x6906e0e.htm#INTENSIFICATION%20OF%20CROP%20DIVERSIFICATION%20IN%20THE%20ASIAPACIFIC%20REGION%20H.P.M.%20Gunasena*
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