Developing a technique to quantify heterotrophic and autotrophic nitrification in acidic pasture soils

Abstract

A series of laboratory incubation experiments were conducted on soils from Maindample and Ruffy in northeast Victoria and from Whittlesea in the Plenty Valley, north of Melbourne, Victoria, Australia, to develop a technique for quantifying both autotrophic and heterotrophic nitrification in acidic pasture soils. The use of a specific inhibitor of the autotrophic ammonium oxidizers (N-serve) did not completely inhibit autotrophic nitrification in its commonly recommended concentrations (10 and 20 μg g-1 soil) in these soils. The N-serve concentration, which completely inhibited autotrophic nitrification, was found to be 60-80 μg g-1. Varying soil types, pHs, and organic-matter contents affect..