Polytunnel Farming Practices in Mahaweli System H, Sri Lanka: An Evaluation of Socio-Economic and Agronomic Dimensions

Polytunnel farming is increasingly important in Sri Lanka’s dry zone, offering opportunities for year-round cultivation, efficient water use, and improved crop productivity. This study aimed to evaluate the socio-economic characteristics of growers, agronomic practices, technological adoption, and financial viability of polytunnel farming in the Mahaweli System H. Data were collected from 50 randomly selected growers using structured questionnaire and analyzed using descriptive statistics and simple cost–return analysis. Most growers were under 50 years (66%), predominantly male (88%), with 22% holding university degrees, and over half (54%) engaged in full-time farming, earning monthly incomes ranging from LKR 30,000 - 150,000. Floor areas of polytunnels were mainly 93–186 m² (1,000–2,000 ft²), with 84% having chimney vents and 72% using bare-soil floors. Capsicum was the principal crop (69%), with temperature and humidity primarily managed using misters (60%) and shade nets (44%). Drip irrigation (80%) and fertigation (58%) were widely adopted to optimize water and nutrient delivery, while pest management relied primarily on chemical pesticides targeting mites, mealybugs, whiteflies, and aphids. Financial returns were generally satisfactory, though 58% of growers had not yet recovered construction costs, and market access was constrained by a lack of quality certification (84%) and dependence on middlemen. These findings highlight the need to improve pest management strategies, enhance irrigation efficiency, diversify crop selection, and implement targeted market interventions to strengthen both productivity and long-term sustainability of polytunnel farming in the Mahaweli System H.