Agricultural wastes.
D000383:Agriculture; D000818:Animals; D002417:Cattle; D004467:Economics; D005525:Food-Processing Industry; D005579:Fossil Fuels; D007220:Industrial Waste; D007878:Legislation as Topic; D008962:Models, Theoretical; D011200:Poultry; D012722:Sewage; D013552:Swine; D014186:Transportation; D014481:United States
D005579:Fossil Fuels; D007220:Industrial Waste; D012722:Sewage