Abstract
The denitrification potential of selected Hawaiian soils was examined by monitoring the gaseous N production and the NO3 loss during anaerobic incubation. The factors responsible for the varying denitrification capacities of different soil are discussed. Denitrification loss seemed to be important only in soil with large amounts of water-soluble organic matter and nutrients. In the absence of an extremely acidic reaction (pH< 4·0), available energy source appeared to play a dominant role in denitrification. N2O gas was the prime denitrification product in the majority of soil studied. However, in near neutral oils with ample energy materials. N2 was the most important. The implication of this gas evolution pattern in evaluating natural denitrification in field profiles is discussed. Since anaerobic reduction of nitrate to ammonia was shown to be insignificant, NO3 disappearance can form an indirect estimate of denitrification in the absence of other sources of NO3 loss.
