Inhibitory capacities of acetylene on nitrification in two agricultural soils

Acetylene is currently used to distinguish between the relative contributio n of nitrification and denitrification to soil emissions of the greenhouse gas, N2O. The basis of this method is that acetylene at low partial pressur es inhibits nitrification without affecting N2O reduction. This paper repor ts experiments where low acetylene partial pressures were insufficient to t otally inhibit nitrification in an hypercalcareous rendosol at water potent ials higher than -3.5 MPa while they were always sufficient in a redoxic lu visol. (C) 2000 Elsevier Science Ltd. All rights reserved.