section_path: Environmental impact/Reducing environmental impact
section_name: Reducing environmental impact
paragraph_text: Reducing environmental impact
  
  The environmental impact of meat production can be reduced on the farm by conversion of human-inedible residues of food crops. Manure from meat-producing livestock is used as fertilizer; it may be composted before application to food crops. Substitution of animal manures for synthetic fertilizers in crop production can be environmentally significant, as between 43 and 88 MJ of fossil fuel energy are used per kg of nitrogen in manufacture of synthetic nitrogenous fertilizers.