Most alfalfa meals and pellets have an N-P-K ratio of about 3-1-2 or something similar. But the actual level of the numbers, as sometimes printed on the bag, can vary from product to product over a relatively wide range. For instance, a company in Fort Worth used to sell an alfalfa meal which they claimed had more than 10% nitrogen in it.

Also, in addition to these usual plant nutrients, alfalfa also contains triacontanol, a complex alcohol that is a known growth hormone. If you want to see its effects, just scratch a cup or so of alfalfa meal into the soil around your roses and water it in well -- or drench your roses once a week with alfalfa tea, if your nose can stand the punishment.