Quantifying the benefits of reducing synthetic nitrogen application policy on ecosystem carbon sequestration and biodiversity

Abstract

Synthetic Nitrogen (N) usage in agriculture has greatly increased food supply over the past century. However, the intensive use of N fertilizer is nevertheless the source of numerous environmental issues and remains a major challenge for policymakers to understand, measure, and quantify the interactions and trade-offs between ecosystem carbon and terrestrial biodiversity loss. In this study, we investigate the impacts of a public policy scenario that aims to halve N fertilizer application across European Union (EU) agriculture on both carbon (C) sequestration and biodiversity changes. We quantify the impacts by integrating two economic models with an agricultural land surface model and a terrestrial biodiversity model (that uses data from a range of taxonomic groups, including plants, fungi, vertebrates and invertebrates). Here, we show that the two economic scenarios lead to different outcomes in terms of C sequestration potential and biodiversity. Land abandonment associated with increased fertilizer price scenario facilitates higher C sequestration in soils (+ 1014 MtC) and similar species richness levels (+ 1.9%) at the EU scale. On the other hand, the more extensive crop production scenario is associated with lower C sequestration potential in soils (− 97 MtC) and similar species richness levels (− 0.4%) because of a lower area of grazing land. Our results therefore highlight the complexity of the environmental consequences of a nitrogen reduction policy, which will depend fundamentally on how the economic models used to project consequences.

Investigation of Soil Microbial Communities Involved in N Cycling as Affected by the Long-Term Use of the N Stabilizers DMPP and NBPT

“…Over the last four decades, the use of synthetic nitrogen (N) fertilizer in the world's agricultural industry has increased sharply for feeding the increasing world population [1]. However, about 50% of the applied N leaks from the agro-production system through ammonia (NH 3 ) volatilization, nitrous oxide (N 2 O) emissions, and nitrate (NO 3 − ) leaching [2,3].…”

Halving mineral nitrogen use in European agriculture: Insights from multi‐scale land‐use models

“…Our primary focus is to analyze the consequences for agricultural production, prices, land use changes, and GHG emissions at both local (EU) and global levels. Other aspects, such as biodiversity and carbon impacts, have been explored in (Devaraju et al, 2022), and a summary of the policy effects can be found in a related publication (Prudhomme et al, 2022).…”