Influence of oxygen on denitrification and aerobic respiration in soil

摘要

The influence of the partial pressure of oxygen on denitrification and aerobic respiration was investigated at defined P02 values in a mull rendzina soil. The highest denitrification and respiration rates obtained in remoistened, glucose- and nitrate-amended soil were 43 μ1 N20 h−1g−1soil and 130 μ1 O2h−1g−1soil, respectively. At -55 kPa matric water potential, corresponding to 40 water saturation, N20 was produced only belowP0240 hPa. TheKm, for O2was 3.0 x 10−6M. Formation of N2O and consumption of O2occurred simultaneously with half maximum rates atP026.7–13.3 hPa. Nitrite accumulated in soil below 40 hPa and increased with decreasingpO2. The upper threshold for N20 formation in amended soil wasP0233–40 hP