At Lower Farm one of my best seasons was 2012, fifteen years after starting the first garden and having spread 1-1.5in compost from different sources every year. Quite a bit was the neighbour’s horse manure, 18-24 months old.
A different neighbour assures me that “farmyard manure” (he does not say how old, whether its composted) causes build-up of P, as a result of which their peas are always stunted.
However my peas at Lower Farm in 2012 were excellent.
So what gives?
I trust the growth of plants more than soil tests.
Growing can be made to seem complicated by chemists and others who claim to understand “plant food requirements”.
In undug soil, the biology is busy sorting things out, and its more about interactions between plant roots, fungi and soil nutrients than about quantities of molecules.
I would sow, plant and observe, your plants will tell you more than laboratories can.