A farmer has depleted her fields of nitrogen by growing the same crop for many years. What should she apply to the fields to replenish the nitrogen? What form should the nitrogen be in?

Answer: To introduce nitrogen back into the soil you can plant crops that create their own nitrogen like soybeans and other legumes crops or use a chemical fertilizer with nitrogen in it. Crop rotation is also a eco effecieint way for farmers to reduce the risk of nitrate leaking onto the surface.