Soil Microorganisms: Nitrogen Transformation Test (OECD TG 216)
The Soil Microorganisms: Nitrogen Transformation Test according to OECD TG 216 is designed to assess the potential effects of chemicals on the activity of soil microbial communities involved in nitrogen cycling. This test provides key information on how substances may impact soil fertility and ecosystem functioning.
In this study, a test substance is incorporated into a representative natural or artificial soil, which is then incubated under controlled laboratory conditions. The microbial activity is monitored over a typical period of 28 days by measuring the transformation of nitrogen compounds, such as ammonium, nitrite, and nitrate, reflecting nitrification and overall nitrogen turnover.
Key endpoints include changes in the rate of nitrogen transformation relative to untreated controls. The No Observed Effect Concentration (NOEC) is derived to identify concentrations at which the chemical does not significantly affect microbial nitrogen cycling.
This test is essential for evaluating the potential ecological impact of chemicals on soil microbial communities and supports regulatory risk assessment for plant protection products, fertilizers, and other soil-applied substances.
