Ask the manufacturer. (See the link below - )

Here is a link that might be useful: who makes it

"TeraVita SP-90 is a soluble humate powder (soluble salts of humic acids) that contains a minimum of 90% humic acids by dry weight. Humic acids are not a plant food. Humic acids may increase the availability of micronutrients.
TeraVita SP-90 is 100% soluble in water. This enables the product to be applied dry or in a liquid form.
When adding the powder to liquid tanks, thoroughly pre-mix the powder withwater in a separate container before adding it to the final liquid tank.
TeraVita SP-90 is compatible with most companion materials in a tank mix, except those mixes with a very low pH (less than 5.0). It is not compatible with calcium nitrate. To be safe, an initial jar test is always recommended when mixing TeraVita SP-90 with companion materials for the first time. "
The manufacturer suggests applications of 2 to 10 pounds per acre. Your compost, soybean meal, and alfalfa pellets will provide more humic acids then this stuff will.

Be aware that "2 to 10 pounds per acre" says it must be applied in liquid form. I reason thus: 1. the max rate of 1o pounds is 160 ounces per acre, which is 1/3 ounce per 100 sq. ft. bed, a fairly normal size for a garden bed. 2, it's difficult enough to measure out 1/3 ounce, but it's absolutely impossible to distribute that amount evenly over 100 sq. ft. 3. So you make a liquid, as much as you like, and distribute with a watering can. I've faced the same problem with boron (which isn't so soluble, by the way). Regards, Peter.

"The manufacturer suggests applications of 2 to 10 pounds per acre." (That equates to about 2 to 10 grams per 100 sq-ft) "Your compost, soybean meal, and alfalfa pellets will provide more humic acids then this stuff will." Please provide some proof for this assertion. I personally see too many unknowns taken from what's been given thus far to draw such a conclusion and to make a statement like this without any qualifiers, well... pardon me but I think your bias is showing.

To OP.... I realize this thread is 2 years old!!! but on the off chance you're still interested:

I've used Terra-Vita this past summer on 250sq-ft of raised beds planted with veggies... didn't even get through the 1-lb bag.... used maybe 10 oz. (that's weight ounces, not fluid ounces-volume) all totaled by the end of summer. This stuff is extremely light (low density) dried. Very small amounts seem to go a really long way with this product, I think its because its ground into an ultra-fine powder (a huge area providing for access to active molecular sites) and its 100% dissolved (thus easily distribute itself evenly in the soil)... This is how I used it: dissolve 1 or 2 tbs into a small amount of water first because it will take a little time to completely get all the "clumps" out (sort of like using corn starch to make a gravy) then dilute that thick concentrate into the larger amount of water (I was using 20-40 gallons to dilute with) whatever the final solution amount you actually intend to water the plants with. Also you may wish to add something to that solution to bind onto the active sites of the humic molecules before application... I mostly used seaweed extract to add micronutrients... I believe it basically chelates those micronutrients (any ones that aren't already chelated) so they are always available to the plant for absorption instead of getting tied up in the soil. (I've also tried various sulfates at times as well.) Then water your plants with that final solution. In my experience there was demonstrable effect upon the plants just with that tiny amount of humic acid. Hope your experience also went well... post back if you have the time.