44
Introduction
Like a number of segments of the horticultural industry,
bodies involved in container nursery cultivation are facing
severe restrictions on water availability.
Unlike other forms of cultivation, container substrate,
ZDter deficits cDn be PeDsXred directOy by D nXPber oI
methods:
• By weighing
• Indirectly with sensors
• Simulation through using a combination of models and
local weather data
Evapotranspiration (ET)-based irrigation scheduling,
designed to apply water in proportion to plant demand, is
repeatedly being recommended as the best management
practice for conserving water.
Although considerable research has been carried out to
find the Post eIficient PeDns oI PeDsXring (7 OeYeOs in
containers during production, comparatively little research
has been carried out to evaluate the ability of containerized
plants to capture sprinkler irrigation water.
Irrigation capture is an important factor for the reason that
while containers take up only a fraction of the production
area even when closely spaced, there still remains a
SotentiDO Ior SODnt cDnoSies to inÁXence the SroSortion oI
sprinkler irrigation water that is captured relative to that
which falls unintercepted between containers.
For the purpose of this study, the terminology “capture
factor” or CF was used to describe the areas of sprinkler
irrigation capture, based on the supposition that if the CF
is greater than one, then it indicates the plant canopy
is capturing water that would otherwise fall between
containers. A CF level of less than one indicates the plant
canopy is directing water outside the container that would
otherwise fall into the container.
It has previously been observed that the way that plants
are laid out in containers in a nursery will have an effect
on irrigation capture, while the sprinkler irrigation system
in use is liable to also have an effect on
Previous tests carried out have ascertained that when
“Wobbler” type sprinkler heads are used they will generally
bring about an improvement in CF when compared to
impact sprinklers when containers are closely-spaced,
bXt their eIficiency ZiOO diPinish the IXrther DSDrt the
containers are. Research has also shown that increasing
the sprinkler nozzle height from 1.2 meters to 3.6 meters
will increase the CF in a nursery, although placements
greater than 3.6 meters did not increase CF levels.
In order to gain a clearer picture, a series of trials were
recently carried out, with the objective of evaluating the
effect that plant size, container diameter, and container
spacing have on CF, while, at the same time, to compare
irrigation capture levels of wobbler vs. impact sprinklers,
using commonly grown ornamental plant species exhibiting
a range of growth habits to make an accurate assessment.
Materials and Methods
The tests were carried out by the University of Florida at
their test center in Gainesville.
,PSDct sSrinNOer heDds fitted Zith 1o nozzOes rDted
Capturing sprinkler irrigation
water to increase efficiency and
profitability in the cultivation of
container grown ornamental plants
Like a number of segments of the
horticultural industry, bodies involved
in container nursery cultivation are
facing severe restrictions on water
availability