Infiltration is the process through which water enters the soil.
Its efficiency depends upon multiple factors including soil texture, surface condition, organic matter, compaction and existing moisture content.
High infiltration rates generally reduce surface runoff but may also accelerate deep percolation if the underlying soil cannot retain sufficient moisture within the active root zone.
Conversely, poor infiltration may leave significant quantities of irrigation water unavailable despite adequate application.
Engineering interventions should therefore aim to optimise infiltration rather than simply maximise it.
The objective is allowing water to enter the soil efficiently while encouraging favourable redistribution within the biologically active region.