Inhaltszusammenfassung

Olive mill wastewater (OMW) generated in Mediterranean countries is partly applied on soil. The mechanisms leading to unwanted effects on soil quality and plant growth are still largely unknown. The objective of this study was to understand the degradation of OMW organic matter and its phytotoxic and water repellent effects in dependence on four different climatic conditions. We hypothesized that warm conditions with sufficient soil moisture ensure optimal bio...Olive mill wastewater (OMW) generated in Mediterranean countries is partly applied on soil. The mechanisms leading to unwanted effects on soil quality and plant growth are still largely unknown. The objective of this study was to understand the degradation of OMW organic matter and its phytotoxic and water repellent effects in dependence on four different climatic conditions. We hypothesized that warm conditions with sufficient soil moisture ensure optimal biological activity and thus minimize negative effects of the OMW treatment. Therefore, OMW-treated soil was incubated for 60 days under four climatic conditions. During incubation we monitored pH, nitrate, manganese, soil respiration, soluble phenolic compounds, soil water repellency and 948;13C. Additionally, calorific value and thermal stability of the soil organic matter at the beginning and end of incubation were determined. Soil samples of the wet-cold and moist-warm incubation were tested for phytotoxicity using a seed germination bioassay with Lepidium sativum. As a function of climatic conditions, positive and negative effects, e.g. addition of nutrients, phytotoxicity and soil water repellency, were observed. Under dry-hot conditions the soil was still water repellent after 60 days of incubation whereas the wet- hot, moist-warm and wet-cold incubation show that soil will stay wettable if soil moisture before OMW treatment is sufficient. Thus, the impact of OMW treatment on soil quality strongly depends on the environmental conditions which should favor an enhancement of microbial activity to minimize negative effects.» weiterlesen» einklappen

Autoren