Originally Posted by greendoctor
I make my own based on how many lb of each element wanted per 1000 sq ft. The raw materials are 21-0-0, preferably spray grade, potassium nitrate, monopotassium phosphate, and dry soluble chelated micronutrients. I will add liquid 28-0-0 if I want a slow release N in the mix. Otherwise it is applied every 30 days to warm season grasses.
Take out the monopotassium phosphate and you pretty much have my base mix for Warm season turf. County Fertilizer ordinance prevent me from using Phosphate. I am sure I use a different source of Minor elements but the final Blend has got to be close. Truth is I spend more on Minors than Primary elements.
In the Old Days 21-0-0 and Ferrous Sulfate was the weapon of choice by most spray companies because it was cheap and gave a Black Green hue to the Turf. The problem was Ferrous Sulfate is like sand blasting the inside of you spray equipment. I forget who posted they still use that blend.