Spudman March 2023 - 22

Plant biostimulants cover a broad
category of products, including familiar
products like microbial inoculants,
amino acids, seaweed extracts, plant
extracts, and humic and fulvic acids.
So what kind of product is considered
a biostimulant?
The nuances of pesticide law
exclusions also rely on the intent of
product use and claims. For example,
recent research indicates that humic
and fulvic acids help increase yields,
alleviate abiotic stress from heat or
salt, and increase nutrient value in
some plants. Generally speaking, the
current laws do not allow product
label claims to reflect these observed
benefits. The divergence between
label laws and published research
frustrates manufacturers, and
farmers, as you can't advertise possible
product benefits.
Research supports the effectiveness of
humic acid used for potato production.
In potatoes, humic acids have long
been used to help improve phosphorus
uptake, especially given the fact that the
potato plant can be inefficient in the
acquisition and uptake of this nutrient.
Another study indicates that foliar
application of humic acid can enhance
potato plant growth and improve
photosynthesis parameters and fresh
tuber yield under different water
deficits under greenhouse conditions,
which represents an opportunity
to improve crop production and
sustainable agriculture in arid and
semi-arid regions.
In yet another study, humic acid
was applied to soil planted with potato
crops to decrease the level of the
fertilization program. The two humic
acid doses under the different fertilizer
applications improved vegetative
growth, yield and tuber properties.
In a study entitled " Influence of
Humic Products on Soil Health and
Potato Production, " research trials
were conducted over a 17-year period
to evaluate the efficacy of different
commercial humates on potato
production. Research found that,
collectively, the consistent use of good
quality products in their replicated
research plots in different years resulted
in a yield increase from 11.4% to the
maximum of 22.3%.
22
Spudman * March 2023
IMPROVING THE SOIL
When it comes to growing potatoes
and other crops, fertilizer isn't the
complete answer, unfortunately, as
plant nutrients do not improve soil
health. Fertilizers are designed to add
nutrients to the soil and support plant
nutrition. A biostimulant works as a
supplement to fertilizer to enhance
nutrient uptake, improve nutrient
efficiency and assist tolerance to
abiotic stress. Conventional fertilizers
have little effect on improving soil
characteristics as most nutrients are
made from salt-based fertilizers.
Simply put,
biostimulants can be
defined as any material,
substance, or product
that, when applied
to plants or soil, can
help improve growing
conditions or nutrition
for the plant.
In contrast, some plant biostimulants
can improve soil characteristics and
affect the plant rhizosphere for better
growing conditions. Some biostimulant
products support root system growth,
so fine roots can penetrate surrounding
soil more effectively for improved
water infiltration. Plant biostimulants
can also positively affect the availability
of plant nutrients that occur naturally
in the soil in addition to those added
by fertilization.
Simply put, biostimulants can be
defined as any material, substance, or
product that, when applied to plants
or soil, can help improve growing
conditions or nutrition for the plant.
Biostimulants help a plant to achieve
its genetic potential by decreasing the
effects of variables that can reduce
growth or yield.
Biostimulant benefits are correlated
with increased crop yields; enhanced
crop or plant performance by
improving tolerance to abiotic stress
factors like drought, heat or salinity;
improved root structure and function;
enhanced seed germination and plant
emergence; increased soil nutrient
retention and availability; increased
soil water holding capacity; and
improved nutrient use efficiency.
Plant biostimulants can also be
readily incorporated into existing
agricultural practices, like fertilizer
combinations and foliar sprays, and can
be used in conventional and organic
crop production. Recent research from
the University of Tennessee indicates
that macronutrients, such as nitrogen
fertilizers like UAN32, are conserved
when blended with humic acid to
increase crop performance.
Based on these findings, one might
expect unwavering support of the
biostimulant market, yet manufacturers
still face hurdles in getting their
products into the hands of farmers.
That being said, the plant biostimulant
market is on target to reach $6.79 billion
by 2030, highlighting biostimulant
products' efficacy and demand.
REGULATION WOES
Currently, a good deal of legislative,
regulatory and guidance activity is
underway, with various industry
coalitions coming together to educate
and advocate for biostimulant use and
remove the barriers to gaining market
access efficiently.
Current law divides regulation into
two categories: pesticides and fertilizers.
Unlike pesticides, which are regulated at
the federal level by the Environmental
Protection Agency (EPA), fertilizers
are only regulated by states. Because
biostimulants are neither a fertilizer nor a
pesticide, there is confusion as to who is
responsible for biostimulant regulation.
Marketing and regulating plant
biostimulants is complicated because
biostimulants do not have a regulatory
definition at the state and federal
levels and are not recognized as an
independent class of products. Federal
and state regulatory agencies and
industry representatives are trying
to define biostimulants and are
offering regulatory and nonregulatory
approaches to address labeling and
product availability.
Parties are looking to determine
a responsible approach that builds
Spudman March 2023

Table of Contents for the Digital Edition of Spudman March 2023
