Humates: The Good, The Bad, and The Ugly
About 350 million years ago in the carboniferous era trees evolved to produce a new structural compound, lignin. It took several million years for fungi to evolve to produce the enzymes necessary to break down lignin and so during this time dead trees piled up and because they couldn’t decompose lead to the coal deposits that we see in present day.
Occasionally a water source would flood these areas which had lots of dead trees and that would lead to significant changes in how the decomposition occurred. Instead of breaking down into pure carbon some of the molecular structure of the original cellulose and lignin remained, which over time also became oxidized. These are the humates.
Most of these geological deposits had been flooded by sea water which means that there is a salt contaminant. The source of material from which Future Harvest uses are formulated from was originally flooded by a fresh water lake, which means there’s lower salinity and less heavy metals than products formulated with other sources of humates.
The main function of humates are as chelators. They have a high ratio of carboxyl groups –COOH which loosely bind to metal ions and aid in their absorption into the roots.
There are 3 types of humates which are categorized based on their molecular weight, these are not restricted to a single molecule but rather are a number of similar ones.
are the lightest of the humates and have the highest solubility, are the easiest for the plant to absorb into the roots and have the chelation capacity. In addition to the chelating properties, there is evidence to suggest that fulvic acid is able to mimic auxins which are growth regulators that increase cell division in roots and shoot elongation. In the raw humate material only a small amount is actually fulvic acid and extracting and concentrating it is costly. Unfortunately there is starting to be a lot of products in the market place that claim to have high levels of fulvic acid. These typically turn out to be adulterants like lignosulfates and amino acids. Future Harvest only uses genuine fulvic acid and guarantees to be 100% adulterant free.
are mid-range humates that are not soluble in normal conditions but can be dissolved using a strong alkaline. They have a more limited biological function since the ratio of carboxyl groups is lower and consequently have lower chelating properties. The higher molecular weights also mean that absorption into the roots is more difficult.
has a very high molecular weight and consequently is not soluble in any conditions and consequently cannot be utilized by plants. Over time however soil microbes will break it down into smaller humates. This can take decades however and while it can help with the texture of the soil there’s little immediate benefit to the nutrition of the plant.
An analogy to help understand the relationships of the humates is that a heavy humate could be thought of as a semi-truck. Inside of the city it’s not always the best way of getting around. Let’s suppose that semi is loaded with bicycles, once they’re unloaded they are able to go most places many that would never be accessible driving the semi. The bicycles would be analogous to fulvic acid as they’re a low smaller and way more versatile than the heavier humates.
One of the downsides to the chelation properties of humates is that they have a preference to bind heavy metals such as mercury or lead over essential metals like calcium or magnesium. For this reason it is very important that the grower be aware of the heavy metal content of their fertilizers as well as use high quality medium and water since one could accidentally introduce these contaminants into their plants which in turn could get consumed by people.