Water entering soil. Lipiec et al. (2005) Geophys. Res. Abs. 7, 02621 find that tillage increases soil porosity, and thus infiltration. Reduced tillage and stubble retention practices can greatly reduce surface sealing and improve infiltration rates. Soil type is significant—sands take in water faster than loams and clays; see Koelliker and Duell (1990) ASAE Paper 902568 on the effects of burning on infiltration. Infiltration may not occur if the speed of the water is too great.

Infiltration capacity

is the maximum rate at which water can infiltrate the soil, and a key determinant of the volume of surface run-off, which occurs when rainfall exceeds a soil’s infiltration capacity. Relative infiltration capacity is the ratio of mean precipitation intensity to saturated hydraulic conductivity (Berger and Entekhabi (2001) J. Hydrol. 247, 3).