aSK EriK
Is controlled environment agriculture (CEA)—A.K.A.
sealed-style indoor growing—really more productive
than traditional in/out style environmental control for
growing crops? Obviously, there would be advantages
to each, but when it comes down to yield, is the
extra expense worth it in harvest weight?
Erik Biksa
In most instances where a CEA system is set-up correctly, it will
outproduce over the majority of in/out set-ups. Where the
real value is for growers, including in terms of yields, is in the
consistency of the harvest in both weight and harvest quality.
With in/out methods, where exhaust and intake fans
exchange the growroom air with outside air for environmental control and cooling purposes, what happens indoors
in your growing environment is still influenced by outdoor
climate conditions. For example, in the summertime, even
at night, it might be too warm outside to effectively use
outside air to cool the indoor growing environment when
the lights are running. The result: either shut down or
watch crop yield and quality suffer (while you work harder
to prevent further plant stresses even though you know
your yield will be less). So, indoor growing—which is not an
inexpensive endeavor in the first place—becomes more of a
dice game when you use in/out ventilation.
While CEA costs more to set-up initially because you
have to invest in A/C, CO2 (carbon dioxide) supplementation and humidity control (versus fans and simple
controls), it affords growers consistent control of the
growing environment. It also allows for effective enrichment of CO2 levels in the growing environment, which
can shorten cropping time and potentially add 10 to 25%
more yield in most instances.
Because growers can maintain set-points consistently with
A/C versus outside air, plants are never stressed by the
environment, which allows them to be healthier and produce bigger yields. It also means fewer cropping problems
like insects or plant diseases, thus eliminating the need for
chemicals or other potentially harmful substances that are
commonly used as control measures.
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Maximum Yield USA | June 2013
Experienced growers usually have a strain or two
they have worked with for years, discovering the
“likes” and “don’t likes.” Often, the frustrating
part is not being able to do anything about meeting these needs exactly because the environment
simply won’t allow for it. CEA methods eliminate
this headache and give you the keys to consistently
healthier and heavier yields because it is possible
to provide the right environment for the desired
response from the crop.
CEA methods can be more power intensive with the
electrical draw required for air conditioners because
you need about 4,000 BTUs of cooling power for
every 1 kW of high intensity discharge (HID) lighting.
However, some growers offset this footprint by capturing and recycling the water lost into the air from the
crop via condensate capture from dehumidifiers and
air conditioning equipment. Not only is this pure
and living water, it also tells the grower exactly when
the best time to water again is (when the water barrel
is full again)—all of this from the plants! You can
recycle the water over and over, although most growers usually will add this to fresh RO-filtered water.
So, there are a few thoughts for you to consider.
Typically, new growers are wise to try a small crop
or two with in/out methods when the season is
favorable, and then expand into CEA as they gain
some experience and success.
Cheers,
Erik Biksa
grozine.com