Microplastics and microglass are used in a wide range of everyday and industrial application acting as abrasives, filler and binding agents, which could enter aquatic and terrestrial environments with unexpected consequences for ecosystems. Our study provides hints, that different types of microparticles seem to have contrary effects on soil microorganisms depending on the origin and properties of microparticles. This study should be seen as basis for further research which is urgently needed.

Soil quality depends on the functioning of soil microbiota. Only few standardized methods are available to assess this as well as adverse effects of human activities. So, it is needed to identify promising additional methods that target soil microbial function. Discussed are (i) molecular methods using qPCR for new endpoints, e.g. in N and P cycling and greenhouse gas emissions, (ii) techniques for fungal enzyme activities, and (iii) field methods on carbon turnover such as the litter bag test.

A widely overlooked source of carbon (C) in the soil environment is organic C of geogenic origin, e.g. graphite. Appropriate methods are not available to quantity graphite and to differentiate it from other organic and inorganic C sources in soils. Therefore, we examined Fourier-transform infrared spectroscopy, Thermogravimetric analysis and the smart combustion methods for their ability of identifying and quantifying graphitic C in soils. Smart combustion method showed most promising results.