Which of the following is not a benefit of nitrogen fixation?

Nitrogen fixation is the process by which atmospheric nitrogen is converted into a form of nitrogen that can be used by plants, such as ammonia or nitrates. 

Nitrogen fixation increases the amount of available nitrogen in the soil, which can improve soil fertility and support plant growth. It reduces the dependence on synthetic fertilizers, which can be expensive and harmful to the environment. It can lead to higher crop yields, as plants have access to more nitrogen, which is an essential nutrient for plant growth.

Nitrogen fixation does not cause soil erosion. In fact, nitrogen-fixing plants, such as legumes, can help prevent soil erosion by binding soil particles together and improving soil structure.