Micronutrient sources?

[bower]

We used to think that kelp was a source of potassium, with a few plant hormones and micronutrients thrown in for good measure. Turns out there is not such a huge amount of potassium, and there is a lot more to the seaweed benefits than a bit of cytokinin.

Some of the high molecular weight polysaccharides in seaweeds have been found to trigger plant defenses against pathogens.

A lot of recent work on stress treatments (cold, salt, drought) has found that glycine betaine and similar solutes make very effective stress treatment for plants - this is in seaweed as well. Once a week application of gb is recommended for persistent stress conditions like drought or cold - the benefits wear off after a week. I always used seaweed soak as a treatment for transplant stress - especially for bare root trees - but it is just as beneficial to veggies.

Here's a nice review of the science behind seaweed benefits and various products:
http://scholar.google.ca/scholar_url...=0CBkQgAMoADAA