Which of the following to maintain the current level of nitrogen in earth's atmosphere ?

Human activities cause increased nitrogen deposition in a variety of ways, including

burning of both fossil fuels and forests, which releases nitrogen into the atmosphere
fertilizing crops with nitrogen-based fertilizers, which then enter the soil and water
ranching, during which livestock waste releases ammonia into the soil and water
allowing sewage and septic tanks to leach into streams, rivers, and groundwater

The points for are used for asking questions, so for example let’s say you have a question that’s really urgent the point scale gives you up to 100 points.. not saying you always need to give 100 points but that’s what they are used for. also answering others questions will give you points.