Highlights
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Input management is vital for the adoption of carp culture by resource-poor farmers.•
TOPSIS and quadratic regression are used to evaluate production optimization.•
Optimal choice of stocking-density, feed, and organic fertilizers are determined.
Abstract
Purulia is a drought-prone and socio-economically underdeveloped district in West Bengal. Resource-poor social groups dominate the population in the district with a high incidence of poverty. The West Bengal Accelerated Development of Minor Irrigation Project (WBADMIP), a flagship project of the Govt. of West Bengal, India, supported by the World Bank, took the initiative in Northeast Purulia to develop composite culture of carps as a viable livelihood option for this section of people. WBADMIP incentives on 172 water bodies in Northeast Purulia revealed that training of the farmers to manage resources and inputs was crucial to succeed in the composite culture of carps. WBADMIP developed a corpus fund out of the profit generated from each water body and motivated the farmers to start the culture independently. This study revealed that the farmers with limited financial capacity could not achieve the targeted production when they started the culture independently, despite proper training. Attempts were made to solve the management of inputs that maximize production under financial constraints. We analyzed the production process of the WBADMIP supported 172 water bodies with a three-stage decision support system: pre-analysis to screen 137 water bodies based on ideal culture duration (>10 months) and ideal depth of the water body (>4 ft) followed by TOPSIS with Shanon entropy analysis to select 73 best water bodies. Then, regression analyses of the inputs of these 73 water bodies were made. Production derived from the quadratic regression equation was found close to actual production in these 73 water bodies. Finally, we solved a constraint optimization to explore the variations in inputs that maximize total production under limited financial conditions. It was revealed that the cost of seed (fingerlings) and supplementary feed were the principal constraints of the resource-poor farmers. While production linearly increased with investment in quality formulated feed, expenditure increased principally on the purchase of fingerlings and the formulated feed. The farmers could maximize production with their limited resources if they would restrict stocking density to 5000 fingerlings per ha and share a part of the capital in purchasing formulated feed. However, if farmers are unable to procure an adequate quantity of formulated feed, an excess input of organic fertilizers along with a limited amount of inorganic fertilizers can be a cost-effective management practice to optimize the production of carps from the composite culture of carps by the resource poor independent farmers.
