Assessment of the Validity of Introducing Nitrate Vulnerable Zones in Large Areas

Groundwater Safety and Availability Index (GSAI) and its association with salinity indicators

This study assesses the quality of groundwater in the Odra River Basin in Poland, focussing on environmental health risks, temporal variability, and their association with salinity indices. A new indicator, the Groundwater Safety and Availability Index (GSAI), was developed to evaluate groundwater resources by integrating health risk and resource quantity factors, providing a novel tool for ranking water resources and informing environmental and administrative decision-making. Groundwater samples were collected between 2005 and 2021 and analysed in accordance with national standards. The results demonstrate an improvement in groundwater quality over time, indicated by a reduction in Health Index (HI) values, particularly in Lower Silesia, Lubusz, and Silesia. Significant correlations were found between HI and NO₃- (τ-Kendall = 0.40) and arsenic (τ-Kendall = 0.55). GSAI values varied across regions, with West Pomerania showing the highest groundwater safety and availability, while Silesia had the lowest. Elevated concentrations of contaminants such as arsenic and nitrates were found to significantly impact water safety, particularly during hydrogeological droughts. These findings support the need for region-specific management strategies to ensure sustainable groundwater use and mitigate health risks, with the GSAI serving as a valuable tool for policymakers and environmental planners.

Nitrates directive restriction: To change or not to change in terms of climate change, that is the question

The positive effect of nitrogen fertilization in agriculture inevitably increases residual nitrogen losses. Water pollution led to legal restrictions of some farm practices within the framework of the Nitrates Directive of the EU. Nevertheless, even several decades later, the situation has not improved significantly. We present a possible science-based explanation of such a state and provide it to farmers and government as a support for environmental management settings. This study aimed to compare an established approach to implementing the Nitrates Directive, specifically the climate-based zoning of nitrogen fertilization restrictions using data from the mid-20th century. We evaluated this approach by juxtaposing the initial climate data with more recent data spanning from 1991 to 2020. Subsequently, we examined this zoning framework from the perspective of the non-vegetative period, characterized by temperatures below 5 °C, which is widely acknowledged as a critical threshold for nitrogen intake by plants. We found out that i) the employed climate-born zoning does not correspond to recent climate data; ii) nonvegetation period is longer than nitrogen fertilization restrictions. Therefore, despite a noteworthy 22 day reduction in the nonvegetation period from 1961/1962 to 2019/2020, we cast doubt on the notion that the period limiting nitrogen fertilizer application should also be shortened, while admitting that there are other abiotic and biotic factors affecting nitrogen behaviour within the ecosystem.