What are the major human impacts on the carbon, phosphorus, and nitrogen cycles?

The carbon, nitrogen, and phosphorous cycles are biogeochemical cycles that represent the movement of these elements (and their chemicals) through the biotic and abiotic components of our Earth. These are natural cycles and human intervention has a significant impact on each one of them.
The carbon cycle represents the movement of carbon and carbon compounds through the biosphere, atmosphere, lithosphere, and hydrosphere. Human beings have a significant impact on the carbon cycle through the combustion of fossil fuels (for industrial applications and automobiles), deforestation, and so on.
Human impacts on the nitrogen cycle are mostly through the application of nitrogenous fertilizers, extensive cultivation of nitrogen-fixing crops (legumes, such as soy, alfalfa, etc.), pollution from vehicular and industrial exhaust, biomass burning, and so on.
The phosphorous cycle has been impacted most significantly by the application of phosphorous fertilizers and raising livestock, especially hogs.
In each case, human beings have increased the amount of the elements (or their compounds) in the lithosphere or atmosphere or hydrosphere thus causing major changes in the cycling of these substances.
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