Trend analysis of Agro-climatic Determinants for Onion Yield Dynamics in Odisha, India

Abstract

Onion (Allium cepa L.) cultivation in Odisha is significantly affected by climatic variability, requiring a comprehensive study of stage-specific meteorological impacts. This study assesses the long-term trends of critical climatic variables, such as, maximum and minimum temperatures, relative humidity, precipitation, and photosynthetically active radiation (PAR) across six principal onion producing districts of Odisha - Balangir, Angul, Kalahandi, Sundargarh, Subarnapur, and Sambalpur. The research employs a comprehensive statistical framework, utilizing a 28-year time-series dataset (1996–97 to 2023–24), which includes descriptive statistics and exponential growth models for Compound Annual Growth Rate (CAGR). The trend analysis shows that rainfall increased during early growth stage, especially in Angul (2.88% in October) but decreased drastically during winter months particularly in Balangir (-7.54% in February). Maximum temperature also exhibited decreasing patterns during bulb growth stages in Kalahandi (-0.21% in January) and minimum temperature during peak winter with Balangir registering -1.14% in December. PAR showed favorable growth in the first growth period as Angul reported 0.85% in September and downward tendencies in the latter stages. Relative humidity showed increasing trends during mid-season months especially in Kalahandi (0.93% in December) indicating beneficial moisture conditions during crop growth. The results give us a number-based way to make climate adaptation plans at the district level that will help smallholder farmers in Odisha keep their yields stable.