If it is not to late take it back and bring home a bag of bone meal (high in nitrogen and phosphorus) or blood meal (high in nitrogen. Good amount of phosphorus and potash). Your soil will benefit from it far better than your $5 bags.
I found some information on of it's contents:
Ammonium nitrate is manufactured by passing ammonia gas through nitric acid.
Potassium sulfate-builds up in soil and becomes a later problem.
Phosphate-again treated with sulfuric acid.
Again with some cons:
Chemical fertilizers kills off micro-organisms that protect plants from certain diseases, your soil is alive due to these organisms. One that keeps adding chemical fertilizers continues to destroy any living antibiotic producing bacteria or fungi that thrive around the plant roots.
Chemical fertilizers'?? quick fix but short term life building. Build good soil organically
