Got my soil test report back and my pH is lower than I expected at 4.8
What is the best way to increase the pH in an established home orchard?
Lime. It's the only method of raising soil pH in widespread use to my knowledge, because it's cheap, easy, and safe as long as you apply per recommended rates and methods.
Apply ground limestone. It works better incorporated but even on the surface will help. The finer it's ground the faster it takes effect. In Illinois we used to apply several tons per acre every few years. Whoever did the soil test should be able to make a recommendation on application rate.
They did recommend 130 pounds per 1000 sq feet. Should I wait till Fall?
That's nearly 3 tons per acre. Now or this fall won't matter much. It doesn't dissipate setting in the sun. But a light incorporation, besides helping it react faster, would help if there is any chance of it being moved about by water.
The local extention office instructed not to apply more than 3000 lb/acre at one time unless tilled, which then I could put down another 1000. Also claimed the 1st application would only effect the top 2" of soil in the 1st year and that I should plan to make applications every fall due to my soil type.
For what it's worth,
Low pH is unusual in most of the USA. Here in Madison, Wisconsin, our native soil, high in clay, has pH around 7.6. Is the soil sample you sent in representative of the general conditions, or was it taken from a spot that had been heavily fertilized?
Maybe you should consider hydrated lime, at least right around trees, to get a jump start and next application maintain the trees with the slower release, and more affordable ground limestone.
The pelletized lawn lime sold at garden centers and garden sections of big boxes is also quicker acting than ground limestone- at least according to their labels.
Are your trees cropping at that pH? If they are doing OK then you are probably fine to go with straight ground limestone.
One mystery about pH for me is that a low pH doesn't bother trees as much in some soils as others. I manage one very large home orchard (former commercial orchard turned into Mcmansion in Greenwich CT) where the owner doesn't want to pay to lime his 5.2 pH soil. His lawn is a mess but his trees are very productive. At other sites adjusting the pH to a higher level seems to be necessary.
I've never been stuck with as acidic a site as yours. Never below 5 at any orchard site I've been asked to manage.
I usually use the pelletized lawn lime because it is easiest to spread accurately, and as I said, allegedly incorporates more quickly. I pass on the price to my customers though- labor is much more significant. Commercial orchards generally use straight white ground limestone delivered by the ton. They pay much less for labor than my customers.
I'm headed to Thompson farm supply they have powered lime in bag fast acting lime. 4.8 is common ph in your location it take 1 ton lime move ph .5 on acre. Fall when rain come as winter moves in good time apply other limes as tail go lime works best second year.
For less work I would add powered lime around drip line some out side drip line every year.
Appling and Bacon county has low ph with a layer of brown Aluminum deep in soil the reason for so many Blueberry Farms.
plant some blueberries. They'll love the soil and you'll have a lot easier time than most of us that are continually working to keep a naturally neutral soil adequately acidic for the acid loving blueberries.