Untersuchung der Auswirkungen von ökologisch erzeugten Biogasgärresten auf Bodenqualität – Ein Methodeneignungstest

Biogas digestate is a by-product of the biogas process and contains high amounts of nitrogen, which makes it a valuable organic fertiliser. In a field trial near Freising, different crop rotations for biogas production were established in 2004/05 and fertilised with digestate only or were not fertilised (controls). A wide range of methods for soil analysis was used between 2013 and 2015 to identify the methods capable of showing a biogas digestate effect on soil quality. We learned that aggregate stability, C and N contents, and the number of earthworms showed significant differences between fertilised and unfertilised plots, while pH, water infiltration, bulk density and pore size distribution were not able to show biogas effects

The Hazard Exposure of the Maltese Islands

International comparisons of disaster risk frequently classify Malta as being one of the least hazard exposed countries. Such rankings may be criticised because: (1) they fail to take into account historic increases in population and its seasonal variation; (2) they are based on inadequately researched and incomplete historical catalogues of damaging events and (3), for small island states like Malta, they do not take into account the implications of restricted land area, which can be disproportionately impacted by even small hazardous events. In this paper, we draw upon a variety of data to discuss disaster risk in the Maltese Islands. In particular, the notion that Malta is one of the ‘safest places on earth’ is not only misleading, but also potentially dangerous because it engenders a false sense of security amongst the population. We argue that Malta is exposed to a variety of extreme events, that include: the distal effects of major earthquakes originating in southern Italy and Greece, plus their associated tsunamis; major ash producing eruptions of Mount Etna (Sicily), and their putative impacts on air transport; storm waves; coastal/inland landslides; karstic collapse; flooding and drought. In criticising international rankings of the islands’ exposure, we highlight the issues involved in formulating hazard assessments, in particular incomplete catalogues of extreme natural events. With Malta witnessing swelling resident, seasonal (i.e. tourist) plus foreign-born populations, and increases in the urban area, further research into hazards is required in order to develop evidence-based policies of disaster risk reduction (DRR)