Not just micro's, but hormones are the real benefit to kelp/seaweed concentrates.
Great point. I kinda skipped over that, figuring it would start a "prove it" BS thread. Not here to argue, just share what I understand.
I would say the biggest benefits are:
prevents common micronutrient deficiencies
Good quality kelp extracts are full of bioactive growth co-factors and often contain significant levels of potassium and a full spectrum of micronutrients including zinc and iron. In natural conditions the growth rate of kelp is prolific, so a lot of the good stuff that helps grow so quickly and vigorously can be made available to your favorite plants.
A lot of the vitamins, amino acids, nutrients and hormones that naturally occur are in a soluble and plant available form in premium quality kelp extracts. Even lesser quality kelp extracts will contain some
levels of these. However, a lot of the difference between premium quality and lesser quality kelp extracts is in what you are not getting
^^ written by Erik Biska, and a note I had bookmarked.
He then later notes:
"Plants that have received kelp in their diets also tend to show better colorations; purple basil is an excellent example of this."
Found that part interesting.
I try and use cold water extracted vs. chemically extracted. Also, some "cheaper" kelp product can be high in sodium...