Indigenous food production systems involve complex processes of producing food from diversified agroecological environments to meet the nutritional requirements of the local people. Women laborers form a loosely structured, informal organization to rear d ucks in common property resources such as communal tanks in south India. Droppings of ducks in the communal tank increase the fish population. The favorable environment for the growth of fish encourages men laborers to spend their leisure time catching fi sh in the tank. The duck-fish production system contributes significantly to nutritional intake of participant households. Sociocultural and economic constraints on the duck-fish production system are identified. Policy options and future directions to s ustain the autochthonous duck-fish production system are suggested.
Increased demand for agricultural labor has created a shift from a labor-intensive cropping pattern to one of extensive cropping in many agricultural regions of India. This has led to a substantial reduction in the area of major food crops such as rice, s orghum, and finger millets. For example, nearly twenty percent of the normal area planted in rice has been converted to casuarina (Casuarina equisetifolia), a multipurpose tree used for fuelwood and house construction, in the Union Territory of Pon dicherry, India during the past few years (Rajasekaran 1992). In addition, rapid urbanization rates have forced marginal farmers to dispose of their lands for non-agricultural purposes. Thus, in spite of a major thrust to increase agricultural production by the Government of India, shrinkage in the area under major food crops has become one cause of malnutrition. DeWalt and Barkin (1991) state that increasing agricultural production through the introduction of agricultural technologies alone will not solv e food and nutritional problems in developing countries. On the other hand, certain indigenous food production systems have been found to contribute significantly to household food and nutritional security (Rajasekaran and Whiteford 1993; Warren 1991). Lo cally produced, nutritionally rich food sources need to be explored and evaluated for their nutritional impact of households (Babu and Rajasekaran 1991).
Indigenous food production systems involve complex processes of producing food from diversified agro-ecological environments to meet the subsistent needs of the local people (Rajasekaran 1992). In addition, these systems are dynamic and complex, reflectin g generations of careful observations of the agro-ecological and socio-cultural environments (Warren 1991). In many instances, they provide steady employment for rural people and thus act as a continuous source of income. Home gardens, forest gardens, ric e-fish culture and rice-crab production are examples of local food production systems (Rajasekaran and Whiteford, 1993).
Home gardening, an indigenous food production system, represents a `genetic backstop', preserving species and varieties which are not economical in field production and are planted in a small-scale for taste, women's preference, and tradition (Ninez 1987) . Of the approximately 300 major vegetables favored today the world over, 200 are produced by backyard gardeners, while only 20 are used in field cultivation (Grubben 1977). Harvesting crabs from the bunds of rice fields is another local food production s ystem practiced by resource-poor people in rice-based farming systems in south India (Rajasekaran and Whiteford 1992). Local people are found to possess an in-depth knowledge of the crabs and their ecology. Moreover, the crabs contribute significantly to the protein intake of the resource-poor households.
Indigenous food production systems, therefore, need to be identified, analyzed, preserved, and disseminated. Using a case-study approach, the overall purpose of this paper is to identify the ethno-ecological and human dimensions of a duck-fish integrated system and evaluate its impact on nutritional security and income among rural poor households in south India. Section one discusses the methodology used in the paper. Section two explores ethno-ecological and human dimensions of the duck-fish production s ystem. Section three determines the impact of duck-fish production on nutrition and income. Section four examines the socio-cultural and economic constraints that are found to jeopardize the sustainability of the system. Section five suggests appropriate policy options to achieve food and nutritional security at the rural poor household level based on the duck-fish production system.
Data for this study were collected over a three month period from the community of Mamandoor, in Thiruvannamalai district, Tamil Nadu, India. The data were obtained in two different, but consecutive phases: (1) rapid rural appraisal; and (2) survey questi onnaire.
Rapid rural appraisal techniques
In most instances, the knowledge systems of local people have never been recorded systematically in written form, hence they are not easily accessible to agricultural researchers, extension workers, and development practitioners (Rajasekaran et al. 1991; Warren and Rajasekaran 1993). Rapid rural appraisal techniques (RRA) developed in recent years seem relevant for eliciting indigenous knowledge systems and also for understanding local conditions efficiently. The rationale behind the use of RRA techniques to record diversified food production systems has been provided by Grandstaff et al. (1985):
RRA is carried out as close to the source as possible. Farmers 'perceptions and understanding of resource situations and problems are important to learn and comprehend because solutions must be viable and acceptable in the local context and because local inhabitants possess extensive knowledge about their settings. I n many instances, RRA researchers have also discovered that farmers are capable not only of devising viable solutions to local problems based on their own understanding, but also conducting relatively sophisticated field experiments in response to local c onstraints and opportunities. For the above reasons, an understanding of indigenous knowledge and practices are extremely valuable for viable and appropriate rural development, and many of the methods, tools and techniques of RRA have been selected for th eir abilities to elicit, evaluate, understand, and avoid misunderstanding indigenous knowledge.
Like many data gathering techniques, RRA is not without drawbacks. In spite of potential problems with such things as replicability of methods, occasional superficiality, or the possibility of poor selection of key informants (or local experts), these cav eats aside, RRA techniques can be powerful tools for obtaining high quality, first rate data (Rajasekaran and Whiteford, 1993).
RRA techniques were intended to explore the components involved in the duck-fish production system. The specific components of the RRA are as follows: participant observations and informal interviews were two RRA techniques used for this study. Participan t observations were conducted to grasp the structure and functions of a local organization established by a group of landless women laborers.2 Informal interviews were conducted among the women laborers to understand the agro-ecological and socio-cultural factors that are found to threaten the sustainability of the duck-fish production system. Data collected from local people using the above techniques were later on compared and contrasted with available research findings to understand the relationship be tween local people's knowledge and expert knowledge.
Two different sampling procedures were employed to draw the sample: (1) random sampling and (2) cluster sampling. Random sampling procedures were used to draw the 10% of the labor households from the village labor households who were involved in the duck- fish production system (Hinkle et al. 1988). Using cluster sampling procedure, all labor households involved in the duck-fish production system were selected as samples for the study and are referred to as participant households in the rest of the paper.< a href = "#fn1"> A 24-hour recall method was employed to collect data on food items consumed by sample participant and non-participant households of the duck-fish production system. The data on the quantity of food items consumed were conver ted into their calorific values and then the intake of energy, protein, calcium, vitamin A and vitamin C per household was calculated (Gopalan et al. 1981). Data were analyzed using the computational facilities available at Iowa State University. A paire d student t-test was used to analyze the differences in the nutritional intake of both sample household types.
Description of the study village
This study was conducted in Mamandoor village, Sambuvarayar district, Tamil Nadu state, India. Mamandoor is a predominantly rice-based farming systems village. The village has access to towns such as Villianoor and Pondicherry located at about 8 and 14 k ilometers respectively which serve as major markets for their produce including the duck eggs. More than 70% of the villagers virtually own no land at all. Most of the villagers depend on large-scale and small-scale farmers for their livelihoods. They earn cash and in-kind income for their services which they use for purchase food and non-food items. They are involved in both permanent employment and on casual labor employment. However, they are not provided with any land to produce their own food.
Duck-fish production system
Village tanks for duck-fish production
There is one communal tank in the village. Village tanks are common property resources owned by the village but managed by public works department. On an average, a village tank occupies approximately eight acres of land and serves 350 acres for irrigatio n. It holds 1600 cubic meters of water during the peak season. According to the local people, this tank serves multiple purposes such as: (1) providing supplemental irrigation for marginal farmers; (2) increasing the water table; and (3) functioning as a feeding lot for the ducks.
The village tank also serves as a habitat for local species of inland fish such as Tilapia, kandai, nethili, and valai. These fish species are native to the tanks and not introduced from outside.
Women's duck-keeping organization
Local organizations play pivotal roles in a number of development projects (Warren 1992). Local organizations are embedded in social structures and characterized by voluntary, personalistic, face-to-face transactions; hence, they tend to be highly partici patory and reflect well their members' interests (Cook and Grut 1989). Twelve women laborers belonging to scheduled caste families have united to form a loosely structured, informal organization. They collectively obtain credi t from one of the large-scale farmers for whom they work as agricultural laborers. The large-scale farmer provides the initial investments to purchase ducklings. The farmer also provides shelter for the ducks adjacent to his farm house. In turn, the large -scale farmer is benefitted by this collaborative arrangement in the following ways: (1) this group of women forms a permanent source of labor for the farmer; (2) the farmer can use the duck manure to improve the soil fertility of his agricultural lands.
Ducklings are purchased from a nearby town. The women laborers rear the ducks on a rotational basis. Each member takes care of the ducks for one day at a time. The women repay the loan with interest to the farmer at the end of the duck-rearing season. The daily responsibilities of the duck care-taker woman include: (a) collecting duck eggs from duck shelters; (b) providing morning feed for the ducks; (c) collecting and heaping duck manure in a compost pit; (d) guiding the ducks to the communal tanks; (e) watching the ducks; (f) guiding the ducks back to the shelters during evening after counting them; (g) monitoring diseases; and (h) separating the diseased ones from the rest of the flock.
Ethno-ecology of duck-fish
The men and women of the participant households in the study village are familiar with the ecology of duck-fish rearing. The women laborers synchronize rearing ducks with the seasonal cropping pattern of the village. The communal tank usually benefits by rains of the south-west monsoon (September-October). The ducklings are usually 10-15 days old when they are purchased. Up to 30 days of age, they are fed with a feed mixture in the morning. The duck feed is prepared by mixing broken rice, rice bran, finge r millets, groundnut cake, and sesame cake. Poor quality groundnut cake and sesame cake are purchased from local markets for preparing feed mixtures at a low cost. Plant juices extracted from weeds such as kuppa meni (Acalypha indica) and kuppa keerai (Amaranthus viridis) are mixed with the feed. According to the women, the plant juices are rich in calcium and thus contribute to increased egg production. The ducks take about 80-90 days before they start laying eggs.
After feeding, the ducklings are herded to harvested rice fields where they forage on rice grains spilled during harvest. After 30 days of age, the ducks are taken to the communal tank. At the beginning of the season, shallow water in the communal tank en ables the ducklings to learn to swim. After the coming of the south-west monsoonal rains, the water level in the tank gradually rises. In the tank, the ducks forage on snails, worms, and other aquatic fauna. Thus, the communal tank and harvested rice fiel ds serve as feeding lots for the ducks. These ducks are raised with a minimum dependence on purchased feed. On the other hand, the purchased feed constitutes 70% of the total production costs in confined duck-rearing industries (Shen 1986). Ducks are gene rally believed to be heat-producing birds. According to some women, the tank water helps them to reduce the heat. This process also stimulates the ducks to consume more feed (Edwards 1986). The duck takes about 120 days before they start laying eggs.
Duck droppings are organic manure, which induces the growth of plankton, a high-protein natural feed for certain fish species in communal tanks (Edwards 1986). Since carbon forms about 50 percent of the biomass of plankton, the high organic content of the manure is an important source of carbon which is released by bacterial respiration. Hence, ducks are referred to as "living carbon manufacturing machines" (Wyonarovich 1979). This nutrient recycling process, in turn, increases fish population in the comm unal tank. The women laborers also believed that the duck droppings encouraged the growth of aquatic snails and worms that act as feed for ducks. According to some farmers, the duck-fish integrated production system increases the organic matter content of the tank silt. Lightfoot and Minnick (1991) also state that fish provide valuable, high-quality protein products and their production systems recycle important nutrients and organic matter.
Local fish-catching techniques
Well-defined gender roles were observed in the participant households. While the women organize themselves to rear ducks, the men concentrate on fish-rearing activity. The favorable environment for the growth of fish encourages men laborers to spend their leisure time catching fish in the communal tank. Grown-up boys assist their fathers in fishing. The men use fish hooks attached to bamboo sticks to catch fish. No social activity was observed as far as fishing is concerned.
Distribution of duck products
After retaining a few eggs for household consumption, the women sell the surplus eggs using three marketing channels: (1) village-level informal purchasing: the farmers and other labor families contact the women's organization to buy eggs informally. (2) village shopper: the village-level shopper buys eggs from the organization on a weekly basis; (3) town markets: the women's organization employs rural youths to sell eggs in town markets in bulk quantities. Considerable cost was incurred for transportatio n for this purpose because the sellers have to depend mainly on public transportation.
Impact on nutritional security, income, and soil fertility
Impact on nutritional security
A paired student t-test analysis revealed statistically significant differences between participant and non-participant households with respect to the consumption of protein, calcium, vitamin A and vitamin C (Table 1). Participant households consumed 18% more protein and 33% more calcium than non-participant households. This increased consumption was evident from the intake of fish by the participant households. Fish alone contributes 41 percent of t he participant households' calcium intake. The significant differences between the two groups with respect to the intake of vitamin A and vitamin C might be due to the fact that the participant households are able to purchase increased quantities of legum es and vegetables such as brinjal (egg plants), tomatoes, and potatoes from the additional income generated from selling the eggs. No statistically significant difference was found between the two household types regarding energy consumption. However, the energy intake of participant households was relatively higher than that of the non-participant households owing to their consumption of fish and duck eggs.
Duck eggs and fish provide cheap sources of protein for the participant households of the duck-keeping organization. Increased fish population in the tank enables the household men to bring home sizeable catches. Thus consumption of fish significantly imp roves the nutritional status of the participant households. According to some women, the tank fish are tastier than fish from other sources. An experimental study conducted in the Philippines also supported this belief. Fish raised in an experimental duck -fish integrated system received a higher rating by a taste test panel than fish from an inorganically fertilized pond (Hopkins and Cruz 1982). Moreover, the participant households could substitute fish for less accessible protein-rich foods such as goat meat.
Impact on income
Duck-keeping activity provides income to women laborers of the local organization. The president of the women's organization shares the income among its members after deducting repayment of capital with interest, transportation cost, and feed cost. The pr esident is also responsible for repaying the loan to the farmer. Most of the income from marketing the eggs is spent to purchase vegetables and dairy products such as milk. Table 2 presents the contribution of duck-fish farming sy stem to household income of participant households. The organization's income per season from duck rearing is given along with the individual income shares.
Improving soil fertility
During the sornawari (first) season (May-August), the tank is almost dry. Local arrangements were made to allow farmers to carry 3 to 4 cartloads of tank silt and apply it to their agricultural lands. The tank silt was found to improve the fertili ty and productivity of the soil. This process also increaes the depth of the tank, which in turn increases its water storage capacity of the tank. We have not accounted for the society benefits to the village by removing silt to increase water storage cap acity.
Socio-cultural and economic constraints
In spite of the advantages of the duck-fish production system, certain socio-cultural and economic factors threaten the sustainability of the system: Fluctuating markets An uncertain market for duck eggs is one of the predominant constraints on the duck-fish system. Searching for market outlets in the towns has become a difficult task for the rural youths. The narrow range of consumers for duck eggs causes these marketing constraints. The women laborers are increasingly discouraged regarding this situation. Moreover, because the surplus eggs are sold through only three channels, it is very difficult to find a dependable market for the produce. Because local people prefer to purchase eggs on credit, this further delays the earning of a regular income.
Fish as feed for ducks
Some participant men believed that allowing more time for ducks to feed in the tank might reduce the future fish population. Moreover, indiscriminate use of chemical pesticides in the surrounding agricultural lands to control crop pests reduced the availa bility of snails and other aquatic fauna.
Decreasing on-farm labor supply
Rice farmers are concerned about the impact of the duck-fish production system on the on-farm labor supply. They expressed their fear that the system in the long run would decrease the labor supply for on-farm operations such as planting, weeding, and har vesting. According to them, the duck-fish production activity already encouraged laborers to demand higher wages.
Interference with tank's irrigation capacity
Most of the marginal farmers without tubewell irrigation depend on the communal tank for at least one-third of the cropping season during the samba (second) and navarai (third) seasons. According to these farmers, duck-fish activity often had interfered with the irrigation activity. On the other hand, the duck-fish people claimed that increased of the tank for irrigation reduces the water availability. Because of the open-access nature of the tank, these two groups of local people had to f ight with each other for access.
Conflicts while fishing
Conflicts were reported regarding the place for fishing. Frequent unauthorized fishing has discouraged the men involved in fishing. This is partly due to the open-access nature of ponds. Since the property rights regarding the use of tank for fishing are poorly defined, the conflict in use of tank for fishing is likely to continue.
Dependency on elite groups
Presently, the large-scale farmer provides capital and shelter for the ducks. The women laborers indicated that it is very difficult to depend on him on a long-term basis. They explained that they have to show up whenever the large-scale farmers call them for on-farm activities.
Some labor households perceived that consumption of duck eggs stimulated the production of intestinal gas for young children. According to them, chicken eggs do not cause these problems.
Demand for tank silt
The quantity of tank silt is not sufficient to meet the needs of all farms in the village. This creates more demand than supply for tank silt among the farmers. Continuance of the system might result in more conflicts regarding who will get how much silt. Breaking local arrangements, some influential and resource-rich farmers have resorted to taking more than their allotted share of silt by using men and machines under cover of night.
Consumption of illicit liquor
Consumption of illicit liquor is one of the major social problems among men laborers in the village (M.S. Swaminathan Research Foundation, 1991). Increased income from selling duck and fish might still increase increase the consumption of liquor among the se laborers.
Caste plays an important role in the duck-fish production system. All the participant households belonged to the scheduled caste. Though few women laborers belonging to other castes are interested in the activity, they would not join the organization anyc ase because the organization has been run by the scheduled caste women. This plays a major contraint in the development of women groups from other social classes and in general reduces the organized way of participating in local development.
Permanent laborers are paid on a monthly basis and they have ongoing work in their landlord's farm. Hence, they find it difficult to participate in the duck-fish activity. On the other hand, casual laborers are paid on a daily basis which allows them to t ake part in the activity when they are unemployed.
Policy Options and Future Directions
A holistic perspective of food production and consumption, in conjunction with the socio-cultural factors, is imperative in designing food and nutritional policies at the resource-poor household level (Rajasekaran and Whiteford 1992). Food policies need t o be redirected to focus on the kinds of commodities that are produced locally and, more importantly, on the kinds of producers who produce them (DeWalt and Barkin 1991). It is essential that food and nutrition policies consider and incorporate socio-cult ural and economic factors.
Strengthening rural marketing linkages
Unless local governments intervene and understand the constraints involved in the marketing of duck eggs, it is highly difficult to sustain the system. The agricultural marketing department of the Tamil Nadu Agricultural University, India, must be encoura ged to conduct market research with an emphasis on consumer behavior and consumer awareness regarding duck products. Understanding the causes for the wide gap between the consumption of the eggs of chicken and ducks is important. Research on ducks that ne glected marketing aspects would not be applicable to producers at the village level.
A separate division under the Tamil Nadu Poultry Development Corporation (TAPCO) needs to be established to strengthen and sustain the production, distribution, and consumption of duck eggs. The division should work in coordination with existing local org anizations such as the one discussed in this paper. Providing disease-free ducklings and opening new marketing avenues holds promise for sustained production and increased consumption of duck eggs. Strengthening the existing village-level marketing option s, analyzing the marketing seasons, interacting with the people involved in marketing, and providing transportation facilities are the first steps to move successfully in this direction. Village-level schools in Tamil Nadu have implemented the government- sponsored Nutritious Noon Meal Program. Though the school food is highly calorific in value, it does not sufficiently provide much needed protein and other nutrients (Babu and Hallam 1989). Steps need to be taken by the school authorities to make use of t he cheap protein available at the village level. The local school headmaster of the study village is optimistic about buying duck eggs for the noon meal program.
Conducting interdisciplinary research
Interdisciplinary research involving inland fisheries scientists, veterinarians, social scientists, and ecologists is essential to study the feeding habits of ducks and their impact on fish population in the communal tank. Communal tanks come under the di rect control of the Public Works Department which needs to be involved in the study process. Another study should examine the effect of the duck-fish system on the irrigation capacity of the tank. A study is also needed to determine the impact of the duck -fish production system on labor supply for on-farm activities. Research should be conducted to study the role of ducks as predators in controlling insect pests in rice fields. Farmers in Dashe Commune, Guagdong Province, China, used ducks to reduce the i nsect population in rice fields (Fuan 1986). While going after insects, the ducks also remove some weeds, and their bills loosen up the soil around the rice plants thus performing intertillage. These indirect benefits of duck farming need to be documented .
Involving state government departments
Public Works Department personnel usually do not permit farmers to remove tank silt in order to protect the tank's environment. But according to villagers, desilting is essential for increasing the storage capacity of the tank and using the silt as manure . Hence, it is essential that the Public Works Department formulate policies to remove and share the tank silt among the farmers without conflicts. This may involve assigning property rights to the users and revenues from such rights might be used for tan k bund management. The Public Works Department personnel should monitor the tank silt distribution activity. The Revenue Department officials should make arrangements to allocate the untitled lands adjacent to the communal tank to the women's organization to use for constructing duck shelters. This would reduce the women's dependency on the large-scale farmer.
Establishing and strengthening local institutions
In certain areas, outsiders such as government agencies and non-governmental organizations (NGOs) have little role to play. Bridging the gap between laborers and farmers and resolving conflicts among men laborers involved in fishing are specific examples. Local institutions need to work with influential farmers and laborers for solutions agreeable to both the groups. For instance, rice farmers should not attempt to discourage laborers' involvement in duck-fish activities. At the same time, the laborers sh ould take up on-farm labor activities in spite of their increased pressure for time. Such mutually beneficial arrangements at the local level would be highly rewarding for sustaining both the duck-fish and crop production activities.
An informal society is needed for men who are fishing. This society would schedule the space and time for fishing for each household which might reduce the conflicts among the men. Assignments of access rights and other regulations are needed to prevent u nauthorized fishing. The duck-keeping organization can serve as a model for NGO's involved in implementing diversified food production systems and developing action plans for similar self-reliant projects in other villages.
Providing formal credit facilities
Credit from informal sources such as large-scale farmers is highly unreliable and is tied to other binding obligations by the women laborers. This may not be sustainable source of credit in the long-run. Sufficient credit facilities are required by the wo men's organization. Credit cooperative societies and commercial banks should take a leading role in this activity. Presently, both credit institutions have a policy to lend only to people who have securities such as immovable properties. This policy is no t favorable for the rural poor laborers who rarely possess immovable securities. Relaxing such policies in favor of laborers would be very helpful. To be eligible to obtain credit from cooperatives and lending banks, the members of the duck-keeping organi zation should retain the status of farm laborers. This policy would encourage the recipients of the credit to work both as on-farm laborers as well as duck-fish producers. This, in turn, enables farmers to venture on labor intensive cropping enterprises.< p> Preventing the production and consumption of illicit liquor
Food policy makers should understand the key social and cultural factors which affect control of household income as well as the allocation of household income for food and other needs (Baer 1991). Socio-cultural factors influencing the consumption of ill icit liquor by household men when they get increased income from marketing duck eggs should be analyzed. Understanding these factors might ead to the development of strategies to control the production and consumption of illicit liquor.
This study identifies duck-fish production, a self-reliant and income generating system developed and implemented by people at the grass-roots level. This study discusses the role of people's participation and use of their knowledge in enhancing local foo d production. In spite of socio-cultural, economic, and institutional constraints, the duck-fish production system plays a crucial role in improving secured food security and nutrition among the labor households. Identifying and recording such an indigeno us food production systems is timely before it is lost for ever. Formulating policies to identify, conserve, and utilize local food production systems that benefit rural laborers and urban consumers is essential.
Indigenous duck-fish production system
1. Bunds are field boundaries used to partition crop lands and the height of these bunds range from 45 cm to 60 cm.
2. Participant observations were provided with information on the number of households that were involved duck-fish production system who were termed as "participant households". The rest of the village households were considered as "non-participant hous eholds."
3. Cluster sampling involves the selection of clusters rather than individual population members. When a cluster is selected for the sample, all members of that cluster are involved in the sample. For this study, the women laborer's organization acts as a cluster sample.
4. The tank water is not used for household purposes. Hence, the household precautions against microorganims in the tank has not arised. However, it is important to analyze the microrganisms to see whether it transmits any diseases.
5. Farmers who possess less than 2.5 acres of cultivated lands are classified as marginal farmers. Farmers who own 2.6 acres to 5.0 acres are grouped as small-scale farmers. Large-scale farmers are those farmers with farm farm holdings of more than 5.0 a cres.
6. The scheduled caste is a class of people who are economically and educationally depressed. A detailed account of the scheduled caste people is provided in Gupta (1985).
7. It is important to note that consumption of calcium and protein is greatly dependent on the quantity of fish caught by men laborers. The survey was conducted during an ideal fish catching period.
8. Considerable work has been done in describing the duck-fish production systems and has been documented in aquaculture literature. However, the puzzle duanting rural development planners is why have these production systems not been successfully adopte d by rural households. Part of the answer lies in understanding the indigenous knowledge of the local people that is combined with the introduced technologies. A technology that is rigid and does not allow for incorporation of indigenous knowledge is unli kely to be successful.
The author would like to thank Professors M.S. Swaminathan, Chairman, M.S. Swaminathan Research Foundation, and D.M. Warren, Director, CIKARD, for having provided the institutional support during the process of research study. Thanks are also due to Rober t S. Chen, Associate Director, Data and Information Resources, Consortium for International Earth Science Information Network (CIESIN) for his encouragements.
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