Mapping of Fe and impact of selected physico-chemical properties on its bioavailability in the apple orchards of Murree region

A survey was carried out to examine and map the Fe status in the soil and foliage of apple orchards in the Murree region to assess the Fe status. Thirteen apple orchards were selected and surveyed from apple producing area on Union Council basis. Sixty five apple trees were selected to collect plant and 130 soil samples from surface and subsurface profile. Foliage Fe concentration was deficient in 46% of the surveyed apple orchards. AB-DTPA extractant technique was used to determine soil available Fe content. Soils of all apple orchards were adequate in plant available Fe content. Factors positively influencing the availability of Fe content included organic matter, clay and silt, whereas pH, sand and calcium carbonate negatively influenced the availability of Fe in orchard soils. Contradictory behavior of soil and foliage Fe content in terms of no or poor correlation indicated a need to mitigate this contradictory behavior by evaluating various extractants and their critical values for the apple orchards.