Infiltration is the process by which water enters the soil.
It separates water into two major hydrologic components, surface runoff and subsurface recharge.
Accurate determination of infiltration rates is essential for reliable prediction of surface runoff (Diamond and Thomas, 2003).
The main goal of operating an irrigation system is to apply an adequate water depth over the field with minimum runoff. To avoid runoff problems, it is necessary to have a good understanding of soil infiltration characteristics when designing and managing infiltration systems.
Sprinkler irrigation is becoming a preferred method as the water available for irrigation around the world becomes increasingly scarce, especially in arid and semiarid regions. Center-pivot is one of the irrigation systems that apply water with high-application rates, especially when operating with low-pressure sprinklers. The use of this irrigation system in soils with low infiltrability usually produces large amounts of runoff and soil erosion problems (Silva, 2007). Therefore, prediction of potential runoff is a very useful tool for proper design and management of center-pivot irrigation systems.
For sprinkler irrigation systems, the soil infiltration rate determines the design application rate to avoid or minimize surface runoff, particularly in areas where water conservation is essentially required (AL-Ghobari, 2002).
Infiltration is affected by properties of irrigation water and soil factors.