Answer:
Producers
Explanation:
Producers are things like plants and bacteria that use energy from the sun through photosynthesis to get energy
The study is either Climatology or Meteorology
Fertilizer is a chemical or has chemicals in it. When the land being fertilized is near water, the fertilizer is washed into the water harming the water and polluting it. Have regulations such as a distance from the water that land must lay, or the amount of fertilizer you can use can help keep the water clean and unpolluted.