Archives of Current Research International

This study evaluated the twenty-year impact of Krishi Vigyan Kendra (KVK)-led extension interventions on farmers’ knowledge, technology adoption, aquaculture expansion, productivity, and profitability in Champawat district, Uttarakhand, India, from 2004 to 2024.

A longitudinal impact assessment approach was adopted using baseline (2004; n = 25) and endline (2024; n = 65) farmer surveys, supported by on-farm demonstrations of scientific composite fish culture and integrated aquaculture models involving fish–poultry, fish–vegetable, and fish–crop systems. Changes in knowledge levels were evaluated using Student’s t-test and Pearson’s χ² test, while productivity and economic performance among production systems were compared using analysis of variance.

Sustained extension interventions significantly improved farmers’ knowledge of scientific aquaculture practices, with mean knowledge scores increasing from 32.44% to 62.76% (P < 0.001). The proportion of farmers belonging to the high-knowledge category increased more than threefold, while very-low knowledge levels declined substantially. During the intervention period, the number of fish farmers and ponds increased by 296.4% and 305.2%, respectively. Fish productivity increased by 80.0%, whereas net profit increased by 344.4%. Demonstration farms adopting scientific composite fish culture achieved 120.5% higher fish production and 150.9% greater net income compared with conventional practices. Integrated aquaculture systems generated additional economic benefits, with fish–poultry farming recording the highest profitability and increasing net income by 517.7% compared with conventional fish farming.