Microbial processes and the site of N2O production in a temperate grassland soil

• Published in: Soil biology & biochemistry Vol. 36; no. 3; pp. 453 - 461
• Main Authors: Muller, C, Stevens, R.J, Laughlin, R.J, Jager, H.J
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Science 01.03.2004; New York, NY
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; denitrification; Fundamental and applied biological sciences. Psychology; gas emissions; gas production (biological); grassland soils; microbial activity; nitrate reduction; nitrous oxide; Physics, chemistry, biochemistry and biology of agricultural and forest soils; rhizosphere; soil chemical properties; Soil science; soil water content; temperate soils; Germany; Grassland; Isotope labelling; Root zone; 15N; Temperate zone; Rhizosphere; Nitrification; Denitrification; Nitrous oxide (N2O); Soil science; Microorganism; Nitrogen protoxide; Grassland soil
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2003.08.027

To understand nitrous oxide (N2O) emissions from terrestrial ecosystems it is necessary to understand the processes leading to N2O production. Here, for the first time, results are presented which identify in situ the processes of N2O production in a temperate grassland soil. A small portion of the nitrogen (N) applied in the summer to the grassland soil was rapidly transported below the main rooting zone (>20 cm) and resulted in large N2O productions at depths of 20-50 cm. Preferential pathways must have been responsible for this movement because the soil conditions were not conducive to leaching by piston flow. The N2O was entirely produced by nitrate (NO3-) reduction which was surprising because the bulk soil was aerobic. Therefore, reduction processes can operate during times of the year when it is least expected and cause large N2O concentrations deep in the soil profile.