In addition to sediment, another important set of water quality constituents are agricultural nutrients. There are many nutrients which are used by plants to help them grow. These nutrients are found in precipitation and the soil.
People apply fertilizers containing nutrients to try and increase plant productivity.
When there is a storm, precipitation detaches soil and also the nutrients. Nutrients are transported in water either sediment-bound or dissolved. These transformations depend on the properties of the water, soils, and nutrients. For water quality, the two most important nutrients are nitrogen and phosphorus. Nitrogen is the dominant component of the atmosphere and is chemically transformed by plants.