Human Influence on the Nitrogen Cycle

Many human activities produce nitrogen pollution which can impact different aspects of the nitrogen cycle and our environment.

Synthetic Fertilizers
Nitrogen-based synthetic fertilizers are commonly used in agriculture. The boost in available nitrogen leads to larger crops, producing more food. However, excess nitrogen within the soil can leach or runoff into surrounding ecosystems. Excess nitrogen can cause soil acidification and eutrophication of aquatic environments. Eutrophication causes algal blooms, which decreases biodiversity.

Fossil Fuels
The burning of fossil fuels also releases nitrogen oxides (NO_x) into the atmosphere. Nitrogen oxides contribute to the formation of smog, acid rain, and climate change. Smog can cause damage to our lungs and harm wildlife, and cause acid rain which acidifies the environment. Nitrous oxide is also a potent greenhouse gas which can contribute to climate change. Major sources of NO_x emissions include vehicles and many industrial practices, including the production of synthetic fertilizers.

Excess waste and sewage dumping
Livestock waste, such as manure, is rich in nitrogen and can be used to fertilize crop fields. However, excess waste makes its way into the environment through dumping or runoff. Sewage from industry is also commonly dumped in waterways. This can lead to acidification and eutrophication.

Human influences on the nitrogen cycle have accelerated the loss of biodiversity, especially among plants adapted to low-nitrogen soils. Subsequently, this impacts the animals and microbes that depend on these plants.