From Agricultural Data into Knowledge Services: A Statistical Analysis of Paddy Yield Trends in Northern Sri Lanka (2004 - 2024)

Abstract

Understanding long-term yield trends and variability in paddy cultivation is crucial for enhancing agricultural productivity, ensuring food security, and guiding strategic policy interventions in Northern Sri Lanka. Despite the agricultural importance of this region, comprehensive district-level analyses of yield trends and irrigation scheme performance remain limited. This study aimed to analyze yield trends, stability, seasonal variability, and irrigation scheme performance, providing evidence-based insights for policy formulation and farmer support. Two decades (2004/2005–2023/2024) of district-wise paddy data (Vavuniya, Kilinochchi, Mullaitivu, Mannar, and Jaffna) covering both Yala and Maha seasons were statistically analyzed using linear regression to quantify yield trends and coefficient of variation (CV) to assess yield stability. Comparative analyses across irrigation schemes (major, minor, rain-fed) and seasons were performed using SPSS statistical software (version 26). The results were compared with the data of Anuradhapura; an adjacent district with a strong reliance on irrigation schemes for paddy cultivation. Findings revealed a significant upward yield trend in Mullaitivu district (55.1 kg/ha per year; R²=0.224, p<0.05), while Vavuniya consistently exhibited the highest average yields (4478 kg/ha) with exceptional stability (CV=11.3%). Yield recovery post-2010 was notably strong in Kilinochchi (22.5%) and Mullaitivu (20.2%). Major irrigation schemes significantly outperformed minor schemes (4197 vs. 3781 kg/ha) and rain-fed cultivation (3158 kg/ha), displaying superior yield stability (CV=19.6%). Interestingly, the Yala season consistently achieved higher yields than Maha across all irrigation schemes, suggesting advantages in controlled irrigation conditions. Anuradhapura district data further contextualizes these findings, revealing consistently high productivity in major irrigation schemes (e.g., 4549 kg/ha in 2004/2005) and demonstrating the critical role of large-scale infrastructure in sustaining yields. The district’s long-term trends highlight the resilience of irrigated systems compared to rain-fed cultivation when considering the trends in rainfall vary in terms of distribution and amount over the past decade. This study provides critical evidence supporting strategic investments in irrigation infrastructure and optimized seasonal management practices. It highlights the value of transforming open agricultural datasets into actionable insights, promoting sustainable agriculture, and informed decision-making in Northern Sri Lanka.