Performance Evaluation and Measurement Techniques for Agricultural Application Nozzles: A Systematic Review of Sprinkler and Pesticide Application Systems

In developing countries, agriculture is vital to the economy, but inefficient water use and shrinking supplies threaten sustainability. Agricultural nozzles (e.g., sprinklers and pesticide sprayers) enable precision farming by delivering water and agrochemicals efficiently, reducing waste and environmental harm. Proper nozzle selection is critical, as specifications and pressure affect droplet size and spray uniformity. Optimal choices can minimize drift, ensure even distribution, and prevent resource losses—improving crop health and conserving water. This review systematically analyses the literature on the spray performance characteristics of agricultural nozzles, including irrigation systems (impact sprinklers, rotary sprinklers, fixed/rotating plate sprinklers, and micro sprinklers) and pesticide application nozzles (flat-fan, twin-fan, and hollow-cone types, with and without air assistance). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we evaluate key parameters such as the coefficient of uniformity, application rate, and kinetic energy for sprinklers, along with droplet size spectra (Dv0.1, Dv0.5, and Dv0.9) for pesticide nozzles—factors that are critically influenced by operating pressure and air assistance. This study further assesses methodologies for measuring droplet size and velocity in both field and laboratory settings, highlighting their advantages and limitations. By synthesizing empirical evidence through a structured PRISMA framework, this review enhances the understanding of spray dynamics, aiming to optimize nozzle selection to improve precision, efficiency, and sustainability in agricultural water and agrochemical applications.