Journal of Experimental Agriculture International

Small and marginal holdings make up roughly four-fifths of operational holdings in Karnataka, a state in southern India where recurrent drought, falling groundwater tables, fragmented land and volatile prices constrain farm livelihoods. The integrated farming system (IFS), in which crops, livestock, fish, trees and allied enterprises are combined on one farm so that the by-products of one component become inputs to another, has been promoted widely as a pathway to higher productivity, profitability and livelihood security for these households. The accompanying literature is large, but it is dominated by favourable single-site reports, and a critical, state-specific assessment of what the evidence can and cannot support has been lacking. This critical narrative review examined peer-reviewed literature and authoritative institutional sources published between January 2000 and July 2026, identified through multidisciplinary and agricultural scholarly indexes and supplemented by citation searching. Evidence was appraised qualitatively for design, comparator, duration, economic accounting and relevance to Karnataka, and was synthesised thematically. Across the included Karnataka comparisons, IFS was consistently reported to have higher net returns and greater labour use than the specialised systems used as comparators, but the evidence consists mainly of station trials and a small number of non-random on-farm comparisons. Confidence in the magnitude and causal attribution of these differences is limited by small samples, the absence of randomised or matched comparisons, inconsistent valuation of family labour and capital, and short study durations. Claims about nutrient recycling are reasonably well supported. Claims about soil carbon, energy efficiency and greenhouse gas mitigation rest largely on accounting estimates and few direct measurements. Evidence that IFS improves household nutrition, reduces income risk or benefits women's welfare is indirect and in places contradicted by broader literature on production diversity, time use and adoption barriers. Integrated farming is better described as a context-dependent redesign of smallholder systems than as a novel or universally superior technology. Priorities include long-term on-farm panels with counterfactual designs, standardised whole-farm accounting, direct environmental measurement and attention to labour, gender and institutional constraints across Karnataka's agro-climatic zones.