Inhibitory capacities of acetylene on nitrification in two agricultural soils

Acetylene is currently used to distinguish between the relative contribution of nitrification and denitrification to soil emissions of the greenhouse gas, N2O. The basis of this method is that acetylene at low partial pressures inhibits nitrification without affecting N2O reduction. This paper reports experiments where low acetylene partial pressures were insufficient to totally inhibit nitrification in an hypercalcareous rendosol at water potentials higher than -3.5 MPa while they were always sufficient in a redoxic luvisol. (C) 2000 Elsevier Science Ltd. All rights reserved.