Journal of Advances in Biology & Biotechnology

The efficiency of aquaculture production systems is primarily influenced by water quality, optimal seed and feed inputs, and, critically, primary productivity, which contributes substantially to biomass yield and economic returns. To assess the level of adoption and the factors contributing to sustainable fisheries development, a baseline survey of 30 fish farmers (10 from each district) was first conducted. Based on the identified gaps, a multi-location trial was carried out under farmers’ field conditions from October 2024 to May 2025. Natural farming-based approaches involving natural-origin organic inputs—cow dung, vermiwash, and fermented slurry—were evaluated for their ability to enhance plankton production and fish growth in composite carp culture across three agro-climatic zones of Punjab (S.A.S. Nagar, Barnala, and Tarn Taran), northern India. Nine fish production units (FPUs), each covering 1 acre, were selected, with three in each district, to evaluate three treatments: T1 (cow dung at 200 kg/acre), T2 (vermiwash at 10 L/acre), and T3 (fermented slurry at 100 L/acre). The results showed that fermented slurry (T3) produced the highest plankton density, fish growth, and fish production (24.23 quintals/acre), followed by vermiwash (22.88 quintals/acre) and cow dung (19.47 quintals/acre). T3 also yielded the highest net profit and benefit–cost ratio (1.92). Vermiwash (T2) produced moderate improvements, whereas cow dung (T1) had the lowest comparative effect. The findings indicate that fermented slurry may be a cost-effective input for sustainably improving pond productivity, reducing feed costs, and increasing farm returns under heterogeneous agro-climatic conditions.