Irrigation-Source Associations and Structural Breaks in Pigeon Pea (Cajanus cajan) in Azamgarh Division, Uttar Pradesh, India

This study examined associations between irrigation-source coverage and pigeon pea yield in Azamgarh Division, Uttar Pradesh, using annual time-series data for 2000-01 to 2021-22. Pearson correlations were calculated between yield and the areas irrigated by canals, government tubewells, and private tubewells. To reduce overfitting in the short series, temporal patterns were described with linear or quadratic trends selected using the corrected Akaike information criterion and leave-one-out cross-validation, and the Chow test was applied to production, yield, and cultivated area. Government-tubewell coverage was significantly and negatively correlated with yield (r =-0.492, p = 0.020), whereas canal coverage (r = -0.360, p = 0.099) and private-tubewell coverage (r = 0.285, p = 0.198) were not significant. A diagnostic multiple regression confirmed that the private-tubewell coefficient remained nonsignificant (p = 0.167), although collinearity among irrigation sources and the absence of rainfall data limit interpretation. Canal and government-tubewell coverage declined, private-tubewell coverage increased modestly, and yield showed a weak positive linear trend. Production exhibited a structural break at the 5% level (F = 4.610, p = .024), whereas yield and cultivated area did not. The findings describe associations rather than causal effects and provide a baseline for field level research on irrigation reliability, climate variability, and sustainable groundwater management.