Best management practice for sport fields and turfgrass
systems should amongst others aim at preventing the rooting zone to become
water repellent. When water repellency develops, it is extremely difficult to
rewet the dry, water repellent soil pockets as water will by-pass these regions
through surface runoff and preferential flow processes. This will result in
irregular wetting of the rooting zone of the soil, and in the long term reduced
turf performance.
In this presentation causes of the development of water
repellency in soils will be discussed and illustrated, as well as its overall
effect on flow and transport processes. Based upon numerous automated TDR
measurements in various water repellent soils, animation
examples of infiltration events will be shown which provide revealing evidence
of the complex nature of flow and transport processes under natural field
conditions. Special attention will be given to the formation and dissipation of
preferential flow paths, the occurrence and persistence of dry spots, and lateral
flow components over time.
Also the use of regular surfactant treatments to prevent
and remediate soil water repellency will be discussed based upon extensive
field trials. Generally, regular surfactant applications result in improved soil
wettability, increased soil water holding capacity, a reduction in irrigation
water requirements, and better turf quality compared with untreated plots.