Alot of sites said 5.5-6.5. Low 6's would be my aiming point.
Keep in mind, typical general AG advice tells you so much an acre. They base that on 6 inches of tillage. I am assuming your not doing any in your orchard.
Typical AG recommendations are .5 to 1.5 tons of lime per acre for a pH increase of 1. 6.3-5.9 is about .4 increase. going up .4 atleast .5 tons/acre for a .5 acre parcel = .4*.5*.5*2000lbs/ton = 200 lbs of lime. IF you went to 300 or 400 lbs on your 1/2 acre, you might be giving it enough. based on the soil you got. 200 to 300 lbs is a safe assumption.
Show your soil test results. Also, keep in mind general tree fertilizer is 20-10-5.
We got better tree experts than me on here. But, this what I would do. Buy 1 bag of 10-10-10, triple 12, or 15. I usually buy triple 12. Use a bit less if going triple. IF you can get 46-0-0 which is all nitrogen urea, maybe add 10-15lbs to it. Buy 5 bags of pelletized lime. Mix all that up. While at it, puts a few lbs of clover in there. Put your spreader on a low setting where it just starts to spread. Go between 2 rows of trees. If you have material left over, go around the perimeter of the rchard, and then more passes inside.
Using fertilizer increases your pH a bit. General AG limes every 3 years. Typical moderate clay is 1 ton per acre every 3 years. Slower use/abuse of nutrients require less.
My camp up north is very sandy soil. Sand does not hold nutrients or ions that balance the pH well. So, I have to add little, but often. My home's heavy clay needs almost 3 or 4 times the lime to adjust the pH, but it holds longer. Both the pH and the nutrient adjustment with fertilizer.
I skip a year at camp with the sand, the plot shows. I get my stuff at home in the right, you can go two years before stuff appears different, but then its not major like with the sand.
Your soil sample results may have a CEC cation exchange capacity. In a rattly nutshell, this is what i described above.
Maintenance dose for me is 1/4 ton / acre up north in clover plots. My pH isn't horrible at home like camp, but I still do 1/4 ton per acre because I fertilizer and till up the spot every 3 years.
I used to be very simple and it worked well for me. 3 bags of lime to every bag of fertilizer used. Worked well for many years, never really had any problems. I have had oak and hickory trees do a day and night differece by liming, a little fertilizer, and watering just enough to keep them from going dormant during a dry spell.
