A little blurb I dug up on Molasses:
The reason nutrient manufacturers have discovered molasses is the simple fact that its a great source of carbohydrates to stimulate the growth of beneficial microorganisms. Carbohydrates is really just a fancy word for sugar, and molasses is the best sugar for horticultural use.
Molasses is a good, quick source of energy for the various forms of microbes and soil life in a compost pile or good living soil. Molasses is a carbon source that feeds the beneficial microbes that create greater natural soil fertility. But, if giving a sugar boost was the only goal, there would be lot's of alternatives. We could even go with the old Milly Blunt story of using Coke on plants as a child, after all Coke would be a great source of sugar to feed microbes and it also contains phosphoric acid to provide phosphorus for strengthening roots and encouraging blooming. In our eyes though, the primary thing that makes molasses the best sugar for agricultural use is it's trace minerals.
In addition to sugars, molasses contains significant amounts of potash, sulfur, and a variety of micronutrients. Because molasses is derived from plants, and because the manufacturing processes that create it remove mostly sugars, the majority of the mineral nutrients that were contained in the original sugar cane or sugar beet are still present in molasses. This is a critical factor because a balanced supply of mineral nutrients is essential for those beneficial beasties to survive and thrive. That's one of the secrets we've discovered to really successful organic gardening, the micronutrients found in organic amendments like molasses, kelp, and alfalfa were all derived from other plant sources and are quickly and easily available to our soil and plants. This is especially important for the soil micro-herd of critters who depend on tiny amounts of those trace minerals as catalysts to make the enzymes that create biochemical transformations. That last sentence was our fancy way of saying - it's actually the critters in live soil that break down organic fertilizers and feed it to our plants.
One final benefit molasses can provide to your garden is it's ability to work as a chelating agent. That's a scientific way of saying that molasses is one of those magical substances that can convert some chemical nutrients into a form that's easily available for critters and plants. Chelated minerals can be absorbed directly and remain available and stable in the soil. Rather than spend a lot of time and effort explaining the relationships between chelates and micronutrients, we are going to quote one of our favorite sources for explaining soil for scientific laymen.
Micronutrients occur, in cells as well as in soil, as part of large, complex organic molecules in chelated form. The word chelate (pronounced KEE-late) comes from the Greek word for claw which indicates how a single nutrient ion is held in the center of the larger molecule. The finely balanced interactions between micronutrients are complex and not fully understood. We do know that balance is crucial; any micronutrient, when present in excessive amounts, will become a poison, and certain poisonous elements, such as chlorine are also essential micronutrients.
For this reason natural, organic sources of micronutrients are the best means of supplying them to the soil; they are present in balanced quantities and not liable to be over applied through error or ignorance. When used in naturally chelated form, excess micronutrients will be locked up and prevented from disrupting soil balance.
Excerpted from The Soul of Soil
by Grace Gershuny and Joe Smillie
