IRRIGATION
How to handle your water without waste
W
hat you can do on
your plot ~
horticulturally at
least ~ depends
in large measure on how
much water you have
available, either in the form of
that which comes from your
borehole or, if you are lucky
enough to enjoy riparian
rights, that which you are
allowed to pump from a
stream or river. There is
Driplines watering lettuce plants
another source, of course,
namely rainfall, and how you
handle and store that is a
complete subject on its own.
For most smallholders,
therefore, irrigation water is
not unlimited and some
attempt must be made to use
it sensibly, if not sparingly.
How you irrigate, and when
you irrigate, and how
frequently you irrigate, will
have a direct bearing on both
the health of your
plants and the
amount of water
you use.
But there is also a
labour component
to the equation.
While a permanently-installed
system may be
more expensive
initially, over a
couple of years the
cost of the labour
involved in moving
pipework and
sprinklers every few hours will
become a factor to be
reckoned with.
Designated, fixed planting
areas with permanently
installed irrigation systems are
the most convenient from a
labour standpoint and can
often be automated to irrigate
at set times and at set rates,
even to the extent of not
switching on when the timer
senses sufficient rain has
fallen.
The drawback of permanently
installed irrigation systems,
however, is that they render it
impossible to cultivate the
growing area mechanically, ie
with a tractor and plough or
rotavator, for fear of damaging
the pipework.
A compromise, which still
allows one to automate the
irrigation process, is to use
movable, semi-permanent
pipework linked to a permanently-fixed timer. In this setup the pipework will be lifted
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out of the field at cultivation
time and relaid before the
field is planted.
The type of irrigation you use
will also be dictated by the
crop you are watering.
Permanent plantings such as
vines and fruit trees can be
irrigated most effectively by
driplines.
A dripline is basically a length
of pipe connected to a tap or
a timer at one end and
sealed at the other, into
which holes are drilled at
exactly the same spacing as
the plants are planted which
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