1. Anderson R V, Coleman D C and Cole C V 1981 Effects of saprotrophic grazing on net mineralization.In Clark F E and Rosswall T (Eds). Terrestrial Nitrogen Cycles. Processes, Ecosystem Strategies and Management Impacts. Ecol. Bull. Stockholm 33, 201–216.
2. Anthonisen A C, Loehr R C, Prakasam T B S and Srinath E G 1976 Inhibition of nitrification by ammonia and nitrous acid. J. Water Pollut. Contr. Fed. 48, 835–852.
3. Ardakani M S, Rehbock J T and McLaren A D 1974 Oxidation of ammonium to nitrate in a soil column. Soil Sci. Soc. Am. Proc. 38, 96–99.
4. Ausmus B S, Edwards N T and Witkamp M 1976 Microbial immobilization of carbon, nitrogen, phosphorus and potassium: Implications for forest ecosystem processes.In Anderson J M and MacFadyen A (Eds). The Role of Terrestrial and Aquatic Organisms in Decomposition Processes, pp 397–421. London: Blackwell.
5. Ayanaba A and Dart P J (Eds) 1977 Biological Nitrogen Fixation in Farming Systems of the Tropics. Chichester-New York-Brisbane-Toronto: John Wiley and Sons. 377 p.