1950-51

RECREATION GROUNDS
681
the rolling which is often necessary to retain a level surface. It
would seem, therefore, that spiking would be a routine operation
on turf for all classes of sport ; this unfortunately is not so.
Spiking by hand is a labour-absorbing occupation, especially
on sports grounds where the area to be dealt with covers several
acres. Much attention was devoted to spiking following the publi-
cation of the results of research work carried out in
1934,
and about
this time a number of engineers were devoting their energies to
designing machines which would perform work equal to or better
than that obtainable with ordinary hand forks but more economical.
During the last four years much progress has been made, and won
there is a wide range of implements from which to choose, either for
manual haulage or for hitching behind tractors or other motive units.
On winter sports turf or cricket outfields a slight disturbance
of the surface as a result of the penetration and withdrawal of the
tines is of little consequence, but on golf greens, tennis courts, cricket
wickets, bowling greens, and other fine turf areas, there must be
no tearing or displacement of the surface during the playing season,
which implies that any machine used for the purpose must make
clean penetration and withdrawal. In this respect many of the
machines are extremely satisfactory.
The influence of the available labour on the amount of spiking
which can be carried out has already been discussed in connection
with hand forks 'and it is again of importance when machines are
considered. A machine capable of operation by one man is of much
greater value to the club with a small staff than one requiring two or
more men, provided that each machine does equally satisfactory
work.
Depth. The depth to which the holes should be made depends
upon the time of year and condition of the turf. For work designed
to encourage a deeper root and better grass growth, the holes
should be as deep as possible at all times of the year, but on account
of harder soil conditions during the summer and drought periods
it may not be possible to go as deep as desired on every occasion.
For assisting water penetration a depth of perhaps two to three
inches is quite satisfactory, but here again the deeper the better.
At the present time machines are capable of penetrating to about
4 to
4-ff'
inches although there are one or two outfits, power driven,
which are capable of penetrating up to
6
inches.
The distance apart of the holes is also important and they should
be as close together as possible. On an experiment carried out at the
St. Ives Research Station the quickest response and recovery after
drought was obtained when the holes were closer together than
farther apart, which is what might be expected, and on this experi-
ment it was interesting to observe that the first response came round
the lips of the holes and gradually extended farther away until the
improvement from hole had joined with that from its neighbour.
Size of Tine.
The size of tine employed depends to some extent
upon the turf conditions and type of work required, but any tine
leaving a
-
clean cut open hole is usually satisfactory. Some tines
are circular and sharply tapered, others more gently, whilst some
are fitted with collars to leave a wide-mouthed hole. Bayonet-