7Osei E, Gassman P W, Hanck L M, et al. Economic costs and environmental benefits of manure incorporation on dairy waste application fields[J]. Journal of Environmental Management, 2003, 68 (1): 1-11.
8Osei E, Gassman P W, Saleh A. Livestock and the environment: lessons from a National Pilot Project [R]. Report No. PR0801.Stephenville, Texas: Texas Institute for Applied Environmental Research, Tarleton State Urfiversity, 2008.
9Martinez J, Dabert P, Barrington S, et al. Livestock waste treatment systems for environmental quality, food safety, and sustainability [J]. Bioresource Technology, 2009, 100(22): 5527-5536.
10Saleem M A M. Nutrient balance patterns in African livestock systems [J]. Agriculture, Ecosystems and Environment, 1998, 71 (1-3): 241-254.
