Nutrient+Cycles


 * September 14, 2010**

Today in class, we learned that nutrients cycle between the Earth spheres (lithosphere, hydrosphere, atmosphere and biosphere). This is similar to the water cycle.

Carbon is found in the soil and atmosphere. It is taken up by plants, which are eaten by animals. Waste processes (animals defecating, animals dying, leaves falling, plants dying) cause plants and animals to turn into detritus. Detritus is decomposed by bacteria and turned back into nutrient-rich soil and carbon dioxide



Nitrogen in soil is taken up by plants, which are eaten by animals. When the animals and plants create waste or die, they produce detritus. Detritus is decomposed by bacteria into soil, and the nitrogen is ready to be absorbed by plants again.



Phosphorous travels through the Earth spheres similar to how nitrogen does. Phosphorous in soil is absorbed by plants, which can be eaten by animals. Plants and animals produce waste and die, which contributes to detritus. Detritus is decomposed by bacteria, which returns phosphorous to the soil.