Controls on nitrification in a water-limited ecosystem: experimental inhibition of ammonia-oxidising bacteria in the Patagonian steppe

• Published in: Soil biology & biochemistry 2003-12, Vol.35 (12), p.1609-1613
• Main Authors: López, Nancy I., Austin, Amy T., Sala, Osvaldo E., Méndez, Beatriz S.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Ammonia monooxygenase gene ( amoA); Ammonia-oxidising bacteria; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Nitrapyrin; Nitrification; Nitrogen; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Semi-arid ecosystems; Soil science
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2003.08.005

We studied controls on nitrification in an undisturbed water-limited ecosystem by inhibiting autotrophic nitrifying bacteria in soils with varying levels of vegetative cover. The activity of nitrifying bacteria was disrupted using nitrapyrin, 2-chloro-6-(trichloromethyl)-pyridine, under field conditions in three microenvironments (underneath shrubs, next to grasses and in bare soil). Ammonia-oxidising bacteria were detected by PCR analysis of DNA in soils. The inhibition of nitrification changed the concentrations of NO 3 − and NH 4 + in the soil, while the microenvironment was most important in determining the response of bacteria to the inhibitor. Nitrapyrin application resulted in a significant ( p