17 billion pounds of fertilizer a year are used to grow animal feed. Producing fertilizer requires significant amounts of energy. Spreading fertilizer generates nitrous oxide, a potent greenhouse gas. Contaminated runoff pollutes surface and ground water.
Combining ammonia with carbon-emitting natural gas to make nitrogen fertilizer is energy-intensive. Fertilizers on soil generate nitrous oxide, a greenhouse gas with a warming potential 300 times greater than carbon dioxide. Phosphorus, another common fertilizer, is mined (as phosphate ore), also requiring fossil fuels. Fertilizer production accounts for 6 percent of the greenhouse gas emissions associated with growing feed for cattle, and 1 percent of the total emissions from beef consumption. The largest impact is from applying – not manufacturing – it.
Mining phosphorus and potassium to produce fertilizer uses large amounts of water and causes water contamination, soil erosion, air pollution and solid waste. Fertilizer often ends up as runoff that pollutes rivers, streams, groundwater and, ultimately, our oceans. Air pollutants include gaseous ammonia, nitric and nitrous oxides, fluorine, sulfur oxides, fertilizer dust and acid mists. Producing phosphorus fertilizer releases radiation from the naturally occurring uranium and radium in phosphate ore. Resulting pollutants in soil and water include nitrogen, phosphate, potassium, sodium, silica, sulfur and fluorine. Solid wastes can include phosphogypsum, pyrite ashes, calcium carbonate and soluble salts from potash refining.