TITLE:
Assessment of the Quality of Irrigation Water at Some Selected Parts of Atwima Nwabiagya North District
AUTHORS:
Vivian Isabella Seshie, Solomon Owusu Ansah
KEYWORDS:
Irrigation Water Quality, Hydrochemistry, Magnesium Hazard (MAR), Soil Dispersion, Sodicity Hazard, Boron Toxicity
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.7,
July
29,
2026
ABSTRACT: The quality of agricultural irrigation water is a critical determinant of crop productivity, soil physical health, and long-term agricultural sustainability. This study evaluated the hydrochemical suitability of water sources utilised for irrigation in selected agricultural zones within the Atwima Nwabiagya North District of Ghana. Seventeen irrigation water sources were sampled and systematically analysed for key physicochemical parameters and calculated agricultural suitability indices, including pH, electrical conductivity (EC), sodium adsorption ratio (SAR), sodium percentage (Na%), magnesium adsorption ratio (MAR), residual sodium carbonate (RSC), soluble sodium percentage (SSP), total hardness, total alkalinity, and concentrations of chloride, sulphate, boron (B), and iron (Fe). Based on calculated SAR (0.41 to 8.17) and RSC (0.11 to 0.55 meq/L) values, all evaluated water sources fell within safe limits, indicating low immediate risks of soil permeability issues. However, the calculated MAR ranged from 46% to 86%, with 16 out of the 17 analysed samples exceeding the critical 50% suitability threshold, signifying a widespread magnesium hazard capable of causing clay dispersion and soil compaction (borehole BH02 [46%] was the sole safe exception). This structural hazard is heavily compounded by highly elevated sodium percentages (Na% > 80% in 12 samples) and soluble sodium percentages (SSP > 80% in 14 samples except BH02 `68.76`, S03 `52.58`, and S12 `77.91`) across the majority of the sampling sites. Furthermore, while the slightly acidic pH (6.07 to 6.99), low EC (