Answer :
Since majority of the Mississippi river basin is cropland, agricultural fertilizers are used extensively in this land . They are a major source of nitrogen.
For example 7 million metric tones of nitrogen in terms of fertilizers are added to the soil annually.
What are the main source of nitrogen?
The primary source of nitrogen in atmospheric deposition is the combustion of fossil fuels like coal and oil. Nitrogen may be deposited in the atmosphere as dry particulates, gases, and droplets or as a wet form such as rain, snow, hail, fog, and freezing rain.
- Atmospheric Nitrogen (Molecular Nitrogen)
- Nitrates, Nitrites, Ammonia in the Soil (Inorganic Nitrogen)
- Amino Acids (Organic Nitrogen) in the Soil
- Organic Nitrogenous Compounds in Bodies of the Insects
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