Answer:
All of these are the most important source of of nitrogen that can lead to eutrophication of aquatic ecosystems
Explanation:
Eutrphication is process where the amount of nutrients in the aquatic system increases. The two major source of nutrients or minerals that causes eutrophication is Nitrogen and Phosphorus. The nitrogen or Phosphorus promotes the growth of phytoplanktons. These phytoplanktons covers the surface of the aquatic system thereby leading to decrease in the amount of oxygen in the system. The runoff from the agricultural lands contains the particles of fertilisers used for the crops.Usually those fertilizers like Urea are made up of Nitrogen and phosphorus. Also the sewage water too contains nitrogen in it.
