Question
If you are using sugar as a substitute for fertilizer will the application of iron hurt ?

Answer
Hi C.A.;
It won't hurt, but you probably don't need it.
An organic source is Texas Greensand ( Glauconite)for a quick greenup.
Use it at 10 to 50 pounds per 1000 sq.ft, depending on how lacking your soil is.
Sugar is not a substitute for fertilizer.
Sugar nourishes the beneficial micrones that enrich the soil.
Because the microbes work round the clock, all year, enriching the soil, it eliminates the need for fertilizers.
Eartyhworms and other beneficial insects and critters tunnel through, and earate the soil. Earthworms eat soil to get the microscopic insects they feed on out, and their droppings ( castings) are what makes a natural fertilizer.
Charlotte