FOLIAR FEEDING
T
“Foliar feeding is a
practice that provides
nutrients to a plant
straight through the
leaf and stem tissues.
If you are looking for
controversies within the
gardening world, you
don’t need to look any
further than this subject.”
110
Maximum Yield USA | June 2016
he most common and important
method for getting our crops the
nutrition they need is by supplying
nutrition to the root system. Foliar feeding is a practice that provides nutrients
to a plant straight through the leaf and
stem tissues. If you are looking for controversies within
the gardening
world, you don’t
need to look any further than this subject.
The concept of feeding
the soil and not the plant is
a popular one in organic gardening, and is based on solid reasoning. In this case the concept of
soil extends to nearly all grow media.
Creating a living soil for your crop to
grow in is a vital goal as plants need
more than just macro- and micronutrients. They need the beneficial bacteria
and fungi along with key hormones that
are responsible for so much of a plant’s
health and vigor. So why feed the leaves?
Does this practice put the goal of building a healthy soil at risk?
The priority of a nutrition regimen for
your crop is always to care for the root
system—the rhizosphere—and see to it
that the plant is thriving and vigorous
through the application of the proper
nutrients and microbes at the correct
quantities. Some questions that come up
are: “Does foliar feeding become a part
of this?”, “Does it really work and if so,
what nutrients, how and when?” and also,
“Am I going to damage or contaminate
my crop through foliar feeding?”
It may seem as though the goal of
organic soil feeding might be by-passed
by practicing foliar fertilization. This may
be why foliar feeding is often looked at
as a poor alternative for providing plant
nutrition. The key word here is ‘alternative’ and this is part of what this article
will explore. Foliar feeding is not meant
to be a substitute for a good soil fertility program, but as an adjunct to one,
allowing the grower to quickly respond to
particular plant and crop issues directly
and avoid further plant symptoms. If a
grower is interested in looking further
into foliar feeding there are a number
of points to research.
What Comprises Foliar Feeding?
Nutrition (fertilizers) applied directly
to the leaf or stem tissues rather than
the root system is considered foliar
feeding. These tissues can be effective
at absorbing various nutrients and have
the benefit of providing this nutrition
throughout the plant’s cell structure
rapidly. Whereas root-absorbed nutrition
can often take several days or weeks to
become omnipresent within the plant,
foliar feeding can begin to correct a
deficiency symptom much faster. Often a
plant’s rhizosphere is in poor condition
and when nutrients are applied they are
converted or absorbed even more slowly.
The plant remains malnourished until
the roots and rhizosphere are repaired
or improved. The most common and
compelling reason for initiating certain
foliar-feeding regimens is to correct a
deficiency. New growth is also receptive
to foliar feeding.
Foliar fertilizers can be organic or
synthetic, though often a type of synthetic fertilizer is used. It is appropriate
that the type of nutrient being applied
is in a form to be readily absorbed and
used by the plant, so synthetics can work
well. Many organic and natural fertilizers
fit into this category but some are not
meant for foliar feeding, they are meant
for building the soil and in turn feeding
the plant. Fish emulsion fertilizers are
a popular type of organic nutrient used
for foliar feeding. Using seaweed extract
or amino acids are other popular and
successful products used for organic
foliar feeding. Of course, solubility and
purity will be a clear priority when selecting a product for this purpose. There is
considerable information available on
the types of organic fertilizers that can
be used for foliar feeding.