If you have flowers, nitrogen isn't the issue. Lack of pollination is often the result of heat stress. Some peppers are more sensitive to temperature than others. Also, peppers just take time to mature enough to produce flowers. Be patient.

Fresh manure provides a BANG! of nitrogen. Pretty soon it's gone. Aged or composted manure and compost actually doesn't provide all that much. NPK is only 1:1:1.

OK, so one more time it's a lesson in patience doing gardening. If only I could be patient NOW!

Not sure where you are, but I should add that cool temps (as in, below 60F) can cause bud drop. Now, I'm suspecting that if your peppers are growing tall, they're plenty warm.

Temperatures in the 90s here. Another post mentioned a lack of phosphorous as a possible cause of a lack of flowers. If this is the case, what's a good source of phosphorous? I have some Dr. Earth fertilizer; would that do it?

Signs of phosphorus deficiency are abnormally dark green or reddish purple color along the edge of the lower plant leaves. More common in acidic soils. Do you see that in any garden plants? You could add phosphates, but if I were you I'd consult with your ag extension first and find out if any phosphorus deficiencies have been recognized in your area. In the United States, phosphorous deficient soils are mostly in the Great Lakes region.