Integrated Aquaculture within Irrigation Options- An Economic Analysis in Indian Context

Increased pressure on fresh water supply leads to a compromise between agriculture and fresh water aquaculture. An aquaculture option within the irrigation system is one of the attempts for efficient utilization of limited fresh water resource. Nine experimental ponds of average waterspread area of 145 m² each were stocked with Indian Major Carps (IMC) with stocking densities of 2, 3.5 and 5 numbers per square meter with three replications. The pond water quality was measured at regular intervals to determine the levels of NO₃, NO₂, NH₃ and PO₄ pollution and water exchange requirements. The ‘so-called’ polluted water for fish was used for irrigating vegetable crops grown in experimental plots of 30 m² size each. To study the response of crop growth using the fish pond waste water enriched in nutrients, Okra (Abelmoschus esculentus L.) cultivar Myhco F-10 and Tomato (Lycopesicum esculentum L.) cultivar MHTM-256 were grown during kharif and rabi seasons respectively. The yield of fish ranged from 3.65 to 6.48 t/ha for different stocking densities. The average yield of tomato obtained from the three treatments and control plots varied between 63.8 to 66.7 t/ha, whereas the average yield of okra varied form 8.76 to 11.38 t/ha. Water exchange interval varied between 20 to 45 days for different stocking densities. The comparison of different treatments under the integrated fish-vegetable cropping system showed significant increase in production due to higher stocking density of fish thereby increasing the profit margin. Therefore, the farmers with a source of water supply, fish ponds and crop lands can have a higher net benefit by adopting this system.