Encyclopedia of Earth
Encyclopedia of Earth: Biogeochemistry: Phosphorus Cycle
Article explaining what the phosphorus cycle is, where it occurs, its place in the biotic world, and the environmental impact of human activities on the phosphorus cycle. (Published: October 8, 2009)
Other
Ed Hume Seeds: Testing Your Soil
Conduct a soil test to find out what nutrients your soil is lacking. This site gives directions on how to gather a soil sample and what nutrients you should test for to get the best soil.
Science Struck
Science Struck: Ground State vs. Excited State of an Atom
Explains what Bohr's model of the atom is, the characteristics of the ground and excited states of an atom, and the electron configuration for each in the example of Phosphorus.