The nitrogen footprint of Ukraine: why personal consumption matters

Unintended reactive nitrogen (N) losses from agriculture, energy and transportation pose significant environmental hazards, including eutrophication, acidification, water and air pollution, biodiversity loss, human health risks and climate change. The concept of a nitrogen footprint (NF) emerges as a pivotal metric, reflecting potential N losses in the entire production-consumption chain of goods and services used by an individual within a defined timeframe.

In a pioneering assessment of per capita NF in Ukraine, key factors, such as the food production chain, consumption patterns, connection to wastewater treatment (WWT) system and the efficacy of WWT facilities, were identified as critical components. Addressing specific challenges, such as data availability, soil N depletion and manure waste, was found to be particularly complex. The apparent high nitrogen use efficiency in Ukrainian cropping systems was highlighted to be actually reflected in the elevated N mineralization rate in Ukrainian soils characterized by high organic matter content. The individual Ukraine NF (22.1 kg N cap−1 yr−1 as of 2017) was found to be much lower than that of the US and Australia being comparable to Western European countries. Even so, significant opportunities for reduction remain through a wide range of options towards healthier and more sustainable dietary choices. Potential reductions, ranging from 22% to 69%, were shown for omnivore, reduced red meat, no red meat, half meat products, vegetarian and vegan diets. In the absence of proper manure management in Ukraine, even greater reductions of an 'actual' NF can be achieved if wasted N manure is considered.

The war's impact is assumed to result in a slight increase or no changes in individual food consumption NFs and an increase in food production NFs for local products, while reductions in individual transport and energy NFs were likely across Ukraine. Nonetheless, refugees massively displaced to less affected regions overload a largely outdated civilian infrastructure, leading to higher N losses.

Looking ahead, sustained support, capital investments, legislative enhancements and regulatory frameworks, especially upon post-war renovation of Ukraine, are imperative for reducing the individual NF. This involves enhancing nitrogen use efficiency in agriculture, establishing efficient manure management, upgrading WWT facilities, promoting renewable energy adoption, bolstering requisite infrastructure and raising public awareness on environmental sustainability.