Questions About Formulating My Own Fertilizer.
The Phosphorus is actually 11.5 lbs. for 23% of 50-lb. bag. I was off by half a Pound. I Corrected it! :-) My Ratios are Right; but it only adds up to 23 Pounds; The Rest is Filler; Am I Correct? *Has long has I kept them dry; I could even use ground up dry leaves for My Own More Organic Dry Filler; Am I Correct?
Genesee County Michigan
I would say no to using leaves as a filler. The function of the fillers is to space out the fertilizer so as to not burn plants from too much of it. Leaves would not do that reliably, at least not uniformly.
"Various materials are used as fillers. Some common ones are: pelleted biosolids, attapulgite clay, vermiculite, montmorillonite, fuller's earth and diatomaceous earth."
The above information is found on page 12 of the following link: http://utbfc.utk.edu/Content%20Folders/Forages/Fertilization/Publications/PB1637.pdf
I suspect you might find other useful information at the above extensive site as well.