The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere,


hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the


movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of


temperature and pressure found on Earth. One important source of soluble phosphorus is the weathering of certain minerals. The


most common source of phosphates in the soil is the weathering of


A)


the mineral apatite.


mineral fertilizers.


9


clays and iron oxides.


microbial action on manure.