Temperature effects on ammonification and nitrification in a tropical soil

• Published in: Soil biology & biochemistry 1975-01, Vol.7 (2), p.83-86
• Main Author: Myers, R.J.K.
• Format: Article
• Language: English
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/0038-0717(75)90003-6

Ammonification of soil organic N and nitrification of ammonium-N was studied in Tindall clay loam over a range of temperatures from 20–60 C. Nitrification rates at each temperature were constant throughout the 28 day incubation, whereas most of the ammonification occurred in the first 7 days. The optimum for nitrification was close to 35 C. exhibiting a sharp peak at this temperature at which the potential rate was 4.8 μg N/g day −1, compared with 0.5 μg N/g day −1 at 20°C and 0.25 μg N/g day −1 at 60°C. The optimum temperature for ammonification was approximately 50°C at which the rate was 2.8 μg N/g day −1 in the first 7 days but only 0.5 μg N/g day −1 between 14 and 28 days. The temperature responses could be described mathematically with functions of the type log o N = k × 1/ T. The results are discussed in relation to daily patterns of N mineralization in the field where temperatures show diurnal fluctuation.