First of all, I am definitely not a mathematician. While 100 grams of molasses does contain roughly 75 grams of carbohydrates, it has 55.5 grams of sugar and the mineral content by weight is still significant. I chose the 100 gram serving for convenience and because most of the vitamins are present in micrograms (the point is that they are there).
Here is the source which I provided on the other occasions I have posted this information, and you can go choose a tablespoon or ounce as you desire to see the content per such a sample.
Still, nutrient content of molasses varies considerably depending on the brand. Plantation Blackstrap molasses contains significantly more calcium (1%), iron (0.018%) and vitamin A than the sample from Nutrition Data. But even assuming those values; the amounts by weight of potassium, magnesium, and iron are quite significant. Especially considering that you can provide the tablespoon (or less) of molasses per gallon just about every watering. Remember, these are trace minerals we're talking about here- they aren't supposed to be there in copious amounts.
Then when you consider the amount of potassium, remember that on fertilizer labels it is expressed as the K20 equivalent and not the actual percentage of potash. So, really 1.77 % K20, which does confuse me as various sources list the NPK of molasses as 1-0-4+. Even so, by weight that is 293 mg of potassium. The Earth Juice products I use only actually contain 165.2 mg of potash. (20 Grams of a 0-3-1 or 2-1-1 = 200mg K20 x .826 = 165.2 mg).
Spanishfly, the sums there don't add up because that isn't the full composition of molasses in terms of chemical components. I see how that could be misleading, but the point is to illustrate that of a 100 gram sample, 55.5 of those grams are actually sugar. Out of a 20 gram sample, 11 grams is 'sugar', 4.4 grams is water, .7 grams ash, and much of what remains is the mineral content, plus a minuscule amount of vitamins (by weight). So really, molasses is mostly sugar
and water- but it is actually a
by-product of sugar manufacturing; the majority of the sugar has been extracted and the minerals concentrated. While sugar certainly remains, the mineral content is no less significant.
It is just annoying as hell when all you're caught up on is that 'molasses is nearly all sugar' and 'wont make your buds any bigger' (even though
nobody here said molasses would make your buds double in size), and 'old wives tale'- because of some dim-witted 'experiment' you did and yet still provide nothing of credence to back yourself up or even elaborate on said 'experiment'. I mean, do you realize that when you make up a fertigation solution it is nearly all water? It's true.
If people want to provide the organisms in their soil with a high energy food source such as sucrose, glucose and/or fructose- what the hell is wrong with that? Molasses is a decent source that just happens to contain significant enough amounts of potassium and trace minerals, is known to influence microbial activity- and really is nothing new.
The use of sugar and molasses to boost soil microbial activity has been talked about for some time and the theory has been that it provides an energy source that can be utilised equally well by all soil organisms. However, field applications have not tended to produce many convincing responses. SWEP research with molasses has shown significant effects on soil biology, but they are more complex than expected.
Again, the best results appeared to be at the lowest application rate (two litres per hectare), with lactic acid bacteria and yeast predictably giving the strongest response, but with fungi and cellulose utilisers also responding (at the lowest rate). Interestingly, photosynthetic bacteria showed the opposite response, with activity increasing as the application rate increased.
http://www.tomatocasual.com/2010/07/15/the-tomato-chronicles-diy-fertilizer/
http://www.bfa.com.au/Portals/0/BFAFiles/AUT05-bioactive-materials.pdf