Anderson N, R Strader, C Davidson. 2002. Airborne reduced nitrogen: ammonia emissions from agriculture and other sources.
Environ. Int., 1011:1–10.
Barger N N, D S Ojima, J Belnap, Wang S, Wang Y, Chen Z. 2004. Changes in plant functional groups, litter quality, and soil carbon and nitrogen mineralization with sheep grazing in an Inner Mongolian Grassland. J. Range Manage., 57:613–619.
Billings S, S M Schaeffer, R D Evans. 2002. Trace N gas losses and N mineralization in a Mojave desert soils exposed to elevated CO2. Soil Biol.
Biochem., 34:1777–1784.
Blake G R, K H Hartge. 1986. Bulk density. In Methods of Soil Analysis. Part 1. Physical and Mineralogical Methods. 2nd Edition.
Agronomy Monogr. #9. Ed. Klute A, et al. pp. 363–367.
de Mazancourt C, M Loreau, L Abbadie. 1998. Grazing optimization and nutrient cycling: when do herbivores enhance plant production?
Ecology, 79:2242–2252.
Fenn L B, J E Matocha, Wu E. 1982. Soil cation exchange capacity effects on ammonia loss from surface-applied urea in the
presence of soluble calcium. Soil Sci. Soc. Am. J., 46:78–81.
Frank D A, P M Groffman. 1998. Denitrification in a semi-arid grazing ecosystem.
Oecologia, 117:564–569.
Frank D A, P M Groffman, R D Evans, B F Tracy. 2000. Ungulates stimulation of nitrogen cycling and retention in Yellowstone Park grasslands.
Oecologia, 123:116–121.
Frank D A, Zhang Y. 1997. Ammonia volatilization from a seasonally and spatially variable grazed grassland: Yellowstone National Park.
Biogeochemistry, 36:189–203.
Gay S W, K F Knowlton. 2005. Ammonia Emissions and Animal Agriculture. Virginia Cooperative Extension.
Publ. No.442–110.
Grabow G. 2007. Overview of Different Lagoon Effluent Application Methods on Odor and Ammonia Emissions. 2007 North Carolina Pork Conference.
http://www.thepigsite.com/articles /1981/overview-of-different-lagoon-effluent-application-methods-on-odor-and-ammonia-emissions.
Kang L, Han X G, Zhang Z B, Sun O J. 2007. Grassland ecosystems in China: review of current knowledge and research advancement. Philos.
Trans. R. Soc., 362:997–1008.
Milchunas D G, W J Parton, D S Bigelow, D S Schimel. 1988. Factors influencing ammonia volatilization from urea in soils of the
shortgrass steppe. J. Atmos Chem., 6:323–340.
Misselbrook T H, B F Pain, D M Headon. 1998. Estimates of ammonia emission from dairy cow collecting yards.
J. Agr. Eng. Res., 71:127–135.
Mulvaney M J, K A Cummins, C W Wood, B H Wood, P J Tyler. 2008. Ammonia emissions from field-simulated cattle defecation and urination
. J. Environ. Qual., 37:2022–2027.
Ni J Q, A J Heber, T T Lim, C A Diehl, A K Duggirala, B L Haymore, A L Sutton. 2000. Ammonia emissions from a large mechanically-ventilated swine building during warm weather.
J. Environ. Qual., 29:751–758.
Pain B F, T J van der Weerden, B J Chambers, V R Phillips, S C Jarvis. 1998. A new inventory for ammonia emissions from UK agriculture.
Atmos Environ.(Ammonia Special Issue), 32 (3):309–313.
Petersen S O, S G Sommer, O Aaes, K SΦegaard. 1998. Ammonia losses from urine and dung of grazing cattle: effect of N intake.
Atmos Environ., 32:295–300.
Ruess R W, S J McNaughton. 1988. Ammonia volatilization and the effects of large grazing mammals on nutrient loss from East African grasslands.
Oecologia, 77:382–386.
Schlesinger W H, W T Peterjohn. 1991. Processes controlling ammonia volatilization from Chihuahuan Desert soils. Soil Biol.
Biochem., 23:637–642.
Sigunga D, B H Janssen, O Oenema. 2002. Ammonia volatilization from vertisols.
Eur. J. Soil Sci., 53:195–202.
Webb J, H Menzi, B F Pain, T H Misselbrook, U D?mmgen, H Hendriks, H D?hler. 2005. Managing ammonia emissions from livestock production in Europe.
Environ Pollut., 135:399–406.
Whitehead D C, N Raistrick. 1991. Effects of some environmental factors on ammonia volatilization from simulated livestock urine applied to soil.
Biol. Fertil. Soils, 11:279–284.
Xu Y, Li L, Wang Q, Chen Q, Cheng W. 2007. The pattern between nitrogen mineralization and grazing intensities in an Inner Mongolian typical steppe.
Plant Soil, 300:289–300.
Xu Y, Wang S, Cheng W, Li L. 2008. Impacts of grazing intensity on denitrification and N2O production in a semi-arid grassland ecosystem.
Biogeochemistry, 88:103–115.