How does phosphorus that forms relatively insoluble inorganic compounds in soils find its way into streams and other waterways? The incorporation of large amounts of wheat straw into a soil may bring...

How does phosphorus that forms relatively insoluble inorganic compounds in soils find its way into streams and other waterways?

The incorporation of large amounts of wheat straw into a soil may bring about P deficiency in the following crop. What is the likely reason for this?