Asparagus bed

My second asparagus bed (approx 10 years old) was definitely less productive last year with thinner and fewer spears whereas the other bed was superb as usual.

I'm considering not harvesting any spears from it at all this year and have mulched it with an extra bag of manure. Do you think that this along with a couple of good feeds with chicken manure pellets once growing would be beneficial for the 2022 harvest? Or maybe just harvest it for 6 weeks rather than 10 8 weeks? Ooops therein may be some of the source of my problem...