Changes in chemical properties of soil and sour cherry as a result of sewage sludge application

This study, aimed at assessment of the effects of different sewage sludge application rates on heavy metal accumulation in the soil and in sour cherry leaves was carried out in the years 2005-2007. The rates applied were 0.0, 2.5, 5.0, 7.5, 10.0 and 12.5 kg of dry matter per tree. Eighteen uniform one-year-old Kutahya sour cherry trees on Prunus mahaleb rootstock were used. Sewage sludge not only improved soil chemical properties but also resulted in an increase of nutrient content in cherry leaves. Sewage sludge application increased heavy metal content of soils. However, this increase did not exceed the critical values and was not reflected in the leaf contents of heavy metals. The most effective application rate was 7.5 kg per tree. Studies should be continued to evaluate the effects of sewage sludge on vegetative and generative growth, yield and fruit quality parameters.