Wrong forum I know, but I like you guys and value your opinions.
My asparagus bed is about 12 years old. About 25 roots originally, plenty of space. About 3 years ago production declined a bit, then the next year it went down to about 1/2 of normal. We had had a dry year, so I attributed it to lack of water, but I also put in another 10 new roots (trench method), in case it was just age. Last year the new growth was good (didn't pick any), the older plants did so-so. I fertilize spring and fall with a regular vegetable garden fertilizer. I tried mulching heavily with sheep manure once about 5 years ago, but felt I had smothered any new shoots. I do have a lot of weeds in the bed, which I pull - have not been able to wage chemical warfare due to our spring weather, and would prefer not to anyway.
I have consulted my local master gardeners (who admit asparagus is not their specialty but have spent a HUGE amount of time trying to help me)and have narrowed it down to moisture and fertilizer.
So my question, what fertilizer do use for your asparagus?