Exploring the importance of Irrigation on Rice Product in Thailand

Abstract

This study investigates the relationship between irrigation and other factors influencing the yields of in-season and out-of-season rice in Thailand. The study focuses exclusively on the overall quantity of rice, without distinguishing between varieties or production processes. Secondary annual time-series data spanning 27 years, from 1994 to 2020. The independent variables include water storage for irrigation, irrigated area, variability in annual average rainfall, the amount of chemical fertilizer used in rice cultivation, variability in the annual average maximum temperature, variability in the annual average minimum temperature, and dummy variables representing the occurrence of El Nino and La Nina phenomena. Testing was conducted to explain the relationships between independent variables and in-season rice yield and out-of-season rice yield through multiple regression analysis using the Ordinary Least Squares (OLS) method. The results indicate that Thailand’s annual average maximum temperature is negatively associated with in-season rice yield, suggesting that higher temperatures tend to reduce yield. For out-of-season rice, the volume of water stored for irrigation has a significant positive impact on yield. In contrast, both the irrigated area and the annual average minimum temperature are negatively correlated with out-of-season rice yield. These findings suggest that the Royal Irrigation Department should prioritize improving on-farm water delivery systems to enhance the efficiency of water distribution, rather than focusing solely on expanding irrigated areas. In addition, the agricultural and agribusiness sectors should adopt climate-resilient farming practices to better adapt to increasing variability in water availability and climatic conditions.