There is only one compelling and practical answer to this problem and that is to work lime into the tree line before planting.
Practical solution (cont from last issue)
Ideally, it should be mixed well to a depth of 60 cm in a strip about 2 m wide when first preparing the tree line hills (ridges).
Soil preparation for orchards may also call for lime to be mixed into the tree lines for soil structural reasons. That’s okay, but no matter how much of the soil preparation methods you adopt, it is most important that a reserve of lime is incorporated into the tree line to give you a buffer against future acidification.
How much lime?
The first step in working out how much lime to use is to determine the pH by taking a composite soil sample from a block to a depth of 60 cm. This should be only surface soil (topsoil).
Analytical laboratories use a standard formula to calculate lime additions, usually in tonnes of pure calcium carbonate per hectare. From this the amount of a certain brand of lime can be calculated.
The aim should be to correct the pH to 6.5 and add a reserve of 1 to 3 tonnes per hectare, depending how acid the soil is as indicated by the soil analysis.
See this article in Tree Fruit July 2022
