plant analysis
“WHILE HYDROPONICS
may seem like the ideal
tool to provide the optimal
level of each element in
a well-balanced nutrient
solution, in reality, nutrition
is much more complex.”
Top: Researchers often use plant analysis to determine optimal nutritional
programs for new crops at different stages of growth. Bottom: Using
plant analysis of a well grown soil crop can be used to formulate nutrient
solutions for new crops, such as these hydroponic peanuts.
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feature
in turn restricting calcium uptake and transportation
within the transpirational flow inside the plant.
Increasing calcium levels in the nutrient solution
to address these low foliar calcium levels (when
levels are not actually deficient) will not assist with
induced mineral deficiencies.
Nutrient interactions can also induce nutrient
deficiencies in the foliar analysis tests despite
there being no actual lack of a particular element
in the nutrient solution. An example of this is in
the use of high levels of ammonium, which also
restricts calcium uptake in the root zone. This can
induce calcium deficiency in the foliage and fruit
of the plant that subsequently shows up on the
foliar analysis reports.
Under certain growing conditions, such as
sub-optimal temperatures, certain plants are
unable to take up iron or phosphorus efficiently
and may show low foliar levels, despite these
elements being present in the nutrient solution at
good levels. If the plant roots have been suffering
from a root rot pathogen or root die-back, foliar
mineral analysis may show multiple deficiencies
in many nutrients; however, this is simply due to
the root system being unable to take up sufficient
minerals from the nutrient solution due to tissue
damage. A lack of oxygen in the root zone can
also induce mineral deficiency. This is also due
to damaged roots being unable to take up the
nutrients required for healthy foliar levels.
To avoid these types of issues, it is usually
beneficial to carry out both nutrient solution
and foliar mineral level testing, particularly in
recirculating systems where certain nutrients may
become depleted rapidly. This data can then be
used to determine if there is an ongoing problem
with the formulation, lack of any one essential
element in the nutrient solution causing low foliar
levels, or another issue effecting uptake and
distribution within the plant.
Where the nutrient product or formulation is
found to be the cause of low, deficient, and even
toxic levels of any element as shown up in a plant
analysis report, this data can then be used to
adjust levels in the nutrient solution. Increasing
deficient levels of most elements in the nutrient
solution will rapidly lead to higher levels of uptake
and incorporation into new leaf tissue. For some
elements, particularly the micro or trace elements,
foliar sprays can also assist to help quickly
overcome a deficiency issue. A follow-up leaf
analysis can then be used to confirm the deficiency
or toxicity problem has been solved.
Plant analysis is likely to become an increasingly
important aspect of indoor hydroponic production
as growers come to understand more of the
complexities of crop nutrition, boosting growth, and
maximizing yields. While hydroponics may seem
like the ideal tool to provide the optimal level of
each element in a well-balanced nutrient solution, in
reality, nutrition is much more complex, and a little
monitoring and plant analysis can go a long way to
reaching the full potential of the system.