The global nitrogen cycle: changes and consequences

doi:10.1016/S0269-7491(98)80010-9

Environmental Pollution

Volume 102, Issue 1, Supplement 1, 1998, Pages 15-24

https://doi.org/10.1016/S0269-7491(98)80010-9 Get rights and content

Abstract

In the absence of human activities, biological N fixation is the primary source of reactive N, providing about 90–130 Tg N year⁻¹ (Tg = 10¹² g) on the continents. Human activities have resulted in the fixation of an additional ∼150 Tg N year⁻¹ by energy production, fertilizer production, and cultivation of crops (e.g., legumes, rice). Some sinks of anthropogenic N have been estimated (e.g., N₂O accumulation in the atmosphere; loss to coastal oceans), however due to the uncertainty around the magnitude of other sinks (e.g., retention in groundwater, soils, or vegetation or denitrification to N₂) a possibly large portion of the N fixed by humans is missing. While we know that N is accumulating in the environment, we do not know the rate of accumulation. Due to the myriad of effects of excess N on humans, ecosystems, and the atmosphere, and their cascading nature (i.e., one atom of N can have a large number of excess N on humans, ecosystems, and the atmosphere, and their cascading nature (i.e., one atom of N can have a large number of different effects as it is transformed to different N species), this lack of knowledge is unfortunate. There are limited options available to society to reduce the amount of N mobilized by human action because there is, in effect, a N imperative — it is required for food production. As population and per capita consumption of food (especially animal products) increase, more and more N will be converted from unreactive to reactive forms in the future. This is especially true in less developed regions.

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View full text

The global nitrogen cycle: changes and consequences

Abstract

Environmental Pollution

Human impacts on the carbon and nitrogen cycles

Vital Signs 1997

Vital Signs 1998

The role of fertilizer in sustaining food security and protecting the environment to 2020

Nitrogen Fixation in Bacteria and Higher Plants

The nitrogen cycle

Scientific American

Reaction of N2O5 on tropospheric aerosols, impact of the global distributions of NOx, O3, and OH

Journal of Geophysical Research

A three dimensional model of the global ammonia cycle

Journal of Atmospheric Chemistry