I finally tested the soil. For record-keeping purposes, I'm posting the full results here:
Front (camellia/strawberry beds)
ph: 7.0 (neutral)
P: adequate
K: sufficient
N: depleted
Upper back (near small pomegranate and lemon tree where the grass is always dead)
ph: 6.5-7.0 (neutral to acid)
P: sufficient
K: sufficient
N: surplus
Lower back (near swing set where grass is always dead)
ph: 7.0 (neutral)
P: surplus
K: sufficient
N: depleted
Bed near apple trees
ph: 7.5 (alkaline)
P: sufficient/surplus
K: sufficient
N: depleted
That's a whole lot of depleted nitrogen, except for the one place in the upper back which makes me wonder if I tested a spot where a chicken recently left me a gift of fertilizer.
In the front where the camellias and strawberries are, I may switch out the strawberries with the blueberries in back. Camellias and blueberries (and an azalea I need to put in the ground) all want acid soil, and the blueberries are not doing well where I put them. Putting them all together would help me control the ph better. Are blueberries "pretty" enough to put in a suburban the front yard?
In the veggie bed near the apple trees, I cover-cropped with nitrogen fixers over the winter, chopped and dropped the plants in spring, covered it all with old hay from the chicken run, and then planted veggies. I thought this would make a nice, nitrogen-rich area for the plants to grow. Apparently not.
So I need to add more nitrogen to the soil in the veggie beds, and I would like to do it without purchasing fertilizer. I think I can use bunny droppings, chicken droppings, or, if I'm brave enough, human urine. (If I could get the family on board, we could make that bed nitrogen-rich in no time! But I just don't see them being interested in peeing anywhere but the toilet.) Any other ideas?