Modeling gypsifereous soil infiltration rate under different sprinkler application rates and successive irrigation events

• Sprinkler drop size-range was decreased with increasing application rate.
• Sprinkler with high application rate had lower kinetic energy and high specific power.
• Soil infiltration rate was significantly decreased with increasing gypsum content and sprinkler application rate.
• A successive irrigation event after the first irrigation does not affect the soil infiltration rate.
• A simple empirical model based on the Kostiakov equation was developed to predict soil infiltration rate.

The marked reduction in infiltration rate caused by formation of a soil seal due to water droplets impact on gypsifereous soil surface is a well-known phenomenon, but is rarely considered in infiltration models, especially under center-pivot irrigation systems. A simple empirical model based on the Kostiakov equation was developed. The model was applied to center-pivot irrigation system for soils with different gypsum contents [60.0 (G1), 137.6 (G2), 275.2 (G3), 314.2 (G4), and 486.0 (G5) g kg−1] under two sprinkler application rates (84.6 mm h−1 for R3000 red-plate sprinkler and 47.3 mm h−1 for R3000 orange-plate sprinkler) and eight successive irrigation events. The impacts of sprinkler droplets kinetic energy as well as specific power on soil surface sealing were evaluated also. A good agreement (P < 0.05) between the measured and predicted infiltration rate values was obtained.