opt] of the ML soil, which never received lime, may have been caused by spatial variation in nitrifier
populations or soil pH in the field, which is a perennial problem under grazed pastures (White et al.
rn] is the relative nitrifier
functionality (0-1); x is the number of days after the application of the nitrification inhibitor; and [beta] is the model parameter to indicate the magnitude of the nitrification inhibition (days).
populations and activities are usually limited by ammonification rates (Haynes 1986).
and denitrifier populations, to a given site and prevalent ecological conditions (i.
In addition, it is not clear whether the treatment of grazed pasture soils with DCD to decrease the activity of nitrifier
bacteria would affect the general microbial population of grazed pasture soils.
Yadvinder-Singh, Beauchamp EG (1989) Nitrogen transformations near localized urea source: Effect of nitrification inhibitor, nitrifier
activity and liming.
2] concentrations include coupled nitrification-denitrification and nitrifier
-denitrification (as discussed below) and it is perhaps possible that these mechanisms are influenced by the same salt and/or ammonia effects on soil nitrifiers
that appeared to occur in the 1000 kg N/ha urine treatment, as noted above.
Further studies on the nitrifier
bacterial composition are required.
Ammonia oxidation pathways and nitrifier
denitrification are significant sources of N2O and NO under low oxygen availability.
Another significant phylum in the CF soil was Cyanobacteria, which is a nitrifier
and contains nitric oxide reductase within its genome (Busch et al.
2]O mainly by the incomplete oxidation of hydroxylamine and by nitrifier
Role of nitrifier
denitrification in the production of nitrous oxide, Soil Biology and Biochemistry 33: 1723-1732.