Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
Sulfur cycle
Introduction References & Edit History Quick Facts & Related Topics
Images
Diagram illustrating the sulfur cycle, showing how sulfur moves through the biosphere and atmosphere. Arrows trace sulfur emissions from fossil fuel burning and decomposition, deposition from the air, plant uptake, runoff into water, and sediment formation.
Quick Facts
Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Diagram illustrating the sulfur cycle, showing how sulfur moves through the biosphere and atmosphere. Arrows trace sulfur emissions from fossil fuel burning and decomposition, deposition from the air, plant uptake, runoff into water, and sediment formation.
Sulfur cycle in the atmosphere Diagram of the sulfur cycle, showing how sulfur moves between the atmosphere, the oceans, the land, and living organisms. Volcanic emissions, biological activity, and human industry release sulfur compounds, some of which form sulfuric acid in clouds and return to Earth as acid precipitation.

Sulfur cycle

ecology
Also known as: sulfur budget, sulphur cycle
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
Last updated
β€’History

Sulfur cycle, circulation of sulfur in various forms through nature. Sulfur occurs in all living matter as a component of certain amino acids. It is abundant in the soil in proteins and, through a series of microbial transformations, ends up as sulfates usable by plants.

Sulfur-containing proteins are degraded into their constituent amino acids by the action of a variety of soil organisms. The sulfur of the amino acids is converted to hydrogen sulfide (H2S) by another series of soil microbes. In the presence of oxygen, H2S is converted to sulfur and then to sulfate by sulfur bacteria. Eventually the sulfate becomes H2S.

Hydrogen sulfide rapidly oxidizes to gases that dissolve in water to form sulfurous and sulfuric acids. These compounds contribute in large part to the β€œacid rain” that can kill sensitive aquatic organisms and damage marble monuments and stone buildings.

Wispy cirrus clouds stretch across a bright blue sky above trees and a river at Pinawa Dam Provincial Park in Manitoba, Canada, with sunlight illuminating the scene.
More From Britannica
Atmosphere: Sulfur budget
The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Adam Augustyn.