A critical review of irrigation water quality index and water quality management practices in micro-irrigation for efficient policy making

Continuous monitoring, improving, and controlling water resource contamination and effective policies are necessary in handling complex agricultural water quality management. The micro-irrigation promoted as efficient water use is entangled by several water pollution problems like corrosion and clogging. This review highlights the key assessment parameters and indexes; pH and temperature interaction, total suspended solids (TSS), electrical conductivity (EC) and total dissolved solids (TDS), turbidity, sodium adsorption ratio (SAR), bacteria and microorganisms’ biofilm, residual sodium carbonate (RSC) from Mg²⁺, Ca²⁺, HCO₃^- and CO₃^2- ion precipitation, magnesium hazard (MH), permeability index (PI), soluble sodium percentage (SSP) and Kelly's ratio (KR). The Langelier Saturation Index, the Ryznar Stability Index, Wilcox Diagram, Gibbs Diagram, Piper Trillinear Diagram, and the United States Salinity Laboratory Diagram are highlighted as the significant water assessment indicators, how they are used and their limitations. It delves into Irrigation Water Quality Index (IWQI) essentially applied to simplify complex water quality reports into information easily comprehensible by experts and policymakers in irrigation water pollution management. The key motive of this article is to showcase indicators applicability along with existing agriculture practices, land use planning, and time-lapse capsules in water quality management. Eventually, modified weighted factors alongside the categorization scheme are presented using amalgamated water quality guidelines. Concerning drip irrigation, consideration of the reviewed indexing practices is emphasized as a practical policy formulation paradigm that can boost the development of practical guidelines and flexibility to embrace multiple water quality parameters.