Aira Lilac I. Pungtilan, Virgilio Julius P. Manzano, Jr., Rodel T. Utrera, Reynold M. Caoili and Bethany Grace S. Calixto
Abstract
This study assessed the physico-chemical properties of groundwater from selected shallow tube wells (STWs) used for irrigation in Brgy. Madamba, Dingras, Ilocos Norte, Philippines. Key physico-chemical parameters and indices were analyzed, including the sodium adsorption ratio (SAR), soluble sodium percentage (SSP), magnesium hazard (MH), residual sodium carbonate (RSC), chloride concentration (Cl-), electrical conductivity (EC), and pH. The results were compared with the irrigation water quality standards of the Food and Agriculture Organization (FAO, 1994). The findings indicate that the groundwater samples are generally suitable for irrigation purposes. However, a gradual increase in SSP values emphasizes the importance of continuous monitoring to prevent potential long-term sodicity hazards. Additionally, a decreasing trend in pH was observed over time, possibly due to the influence of rainfall events during the sampling period. These findings highlight the importance of regularly assessing irrigation water to ensure sustained soil productivity and crop health.