Environmental Engineering Reference
In-Depth Information
Fig. 8.6. The blades of the vertical mower cut vertically into the turf canopy,
severing lateral stems and removing thatch that develops on the surface.
lawns, especially when highly fertilized, may need extensive detaching
every 1-3 years.
Like cores after aerification, dethatching debris contains many viable
sprigs, which can serve as material for vegetative propagation. Dethatch-
ing should be performed at times of vigorous growth and should be
avoided before anticipated periods of environmental stress, such as
drought. After dethatching, fertilizer and water should be applied to
promote rapid turf recovery.
Top-dressing
In agriculture,
top-dressing
refers to application of a thin layer of manure
or fertilizer, but in turf management, it refers to the distribution of a thin
layer of soil over a turf-grass area. It is usually used to cover thatch or to
smooth the playing surface. It is often performed in combination with
other cultural practices such as core aerification and verticutting. High
rates of top-dressing are often applied on newly established greens or
athletic fields for the purpose of covering creeping stolons and smoothing
the surface and are usually continued until the desired shoot density and
smoothness are achieved (Fig. 8.7).
On already well-established and smooth turf, surface top-dressing
should be used as infrequently as possible. If the thatch accumulation
rate is very high, a better choice is to correct its fast build-up by modify-
ing the fertilization programme, correcting soil pH, increasing soil
aeration, and so on, rather than cover it routinely with top-dressing.
