The apple tree can thrive in an average soil with pH close to 7, provided that is well drained and free from stagnated water. However, maximum yields are reported on fertile sandy soils and loams with pH ranging from 6 to 7.
Start by carefully plowing the field in depth of at least 20 inches (50cm) and remove all the weeds.
Add about 20 tons manure per hectare and then plow again superficially. Many commercial apple farmers also add lime to the soil before planting apple trees, in order to fix pH (ask a licensed agronomist).
Keep in mind that 1 ton = 1000 kg = 2.200 lbs. and 1 hectare = 2,47 acres = 10.000 square meters.
When cultivating apple trees commercially, cover crops (which are in most cases low standing grasses) have been reported to be beneficial, if not necessary in some cases.
Cover crops tend to reduce soil erosion during heavy rains or wind storms. They also improve soil aeration and orchard stability, while some of them fix nitrogen.
Finally, they work as a filter for apple trees’ irrigation and they adjust orchard temperature. Alfalfa, vetch, legumes and Trifolium fragiferum (strawberry clover) have been found to be beneficial when they are planted as cover crops in apple farms.