Biological activity of soils in apple orchards differing in fungicide application and copper burden

摘要

The soil biological activity of two different apple orchards was compared using several methods of investigation. Plot R was established with the scab-resistant variety 'Topaz' three years ago. Before it was under arable use. Fungicides were not applied. Plot F has been used as orchard with normal spraying of fungicides for more than 40 years. It is grown with the scab-sensitive variety 'Jonagold' since 1989. The soils of the two plots differ mainly in their content of organic matter (R: 1.7%; F: 2.7%) and of copper (R: 9.6 mg/kg; F: 72.3 mg/kg). The investigated parameters showed either no significant difference between plot F and R or higher values for plot F. The decomposition of wheat-straw and hay, and the CO2-release of the soils in situ were grossly the same in the two plots. Higher values in plot F were found for the feeding activity of soil animals, microbial biomass, nitrification, and most enzyme activities. The results are illustrating primarily the positive influence of organic matter on the biological activity and biomass in soils. There was no evidence of the applied fungicides or the accumulated copper leading to a degradation of biological soil functions.