Assume you add a soluble phosphate fertilizer to an Oxisols and to an Aridisol. In each case, within a few months most of the phosphorus has been changed to insoluble forms. Indicate what these forms...

Assume you add a soluble phosphate fertilizer to an Oxisols and to an Aridisol. In each case, within a few months most of the phosphorus has been changed to insoluble forms. Indicate what these forms are and the respective compounds in each soil responsible for their formation.

How does the phosphorus content of cultivated soils in the United States compare with that of nearby soils under natural vegetation (forests, grasslands) that have never been cleared? What is the reason for this difference?