soil: Quick Facts

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soil profiles on hillslopes

Illustrated diagram of the carbon cycle showing how carbon moves as carbon dioxide through the atmosphere, water, living organisms, rocks, and soil. It depicts processes like photosynthesis, respiration, sedimentation, volcanic activity, fossil fuel use, and carbon sequestration, with arrows indicating the flow between air, water, plants, animals, rocks, and industrial sources.

Colorful diagram of the nitrogen cycle showing how nitrogen moves through the atmosphere, biosphere, and soil. It illustrates natural processes like nitrogen fixation, assimilation, ammonification, nitrification, and denitrification, as well as human activities such as fertilizer use and industrial emissions, with arrows and labels connecting elements like plants, animals, bacteria, and factories.

nitrogen-fixing bacteria

Learn how weathering of rock and the activities of organisms help in soil formation

How Do Plants Absorb Water and Nutrients?

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Topics

soil moisture duricrust soil liquefaction horizon clay humus Vertisol Spodosol Gelisol Aridisol mineral Meteorite mineral deposit rock tektite Dust regolith Climate Why Is Earth’s Axis Tilted?Equator

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Key People

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Curtis Fletcher Marbut

American geologist

Ruffin, Edmund

Edmund Ruffin

American scientist

Selman Abraham Waksman, 1968.

Selman Abraham Waksman

American biochemist