Air temps in the 70's doesn't reflect the actual soil temp which could still be too cold for rapid growth, not knowing your location one can only guess about your local growing conditions. 70's in Delaware vs 70's in South Carolina can make a big difference at this time of year.

I am not sure exactly what you are expecting. Spears are generally not produced in clumps. A mature plant can produce upto 20 spears but over a period of 6-8 weeks. It is not a once and done harvest and the spears do tend to appear individually over this period. That's why it is recommended to plant 10 plants for every family member who will be eating it.

You do not say where you are but my asparagus won’t come through the soil for weeks yet.

You might want to consider giving the bed a Spring dose of a really good, high nitrogen liquid fertilzer. Compost sounds good as a soil helper, but in my opinion doesn't realy work as a fertilizer... unless there is a lot of manure in it. I use to lay a thickish layer of manure over the top of the bed in the late Fall /early Winter; that way it had had all Winter to soak all the goodness deep into the ground. (Remember how far down those crowns are buried.)