Influence of cattle grazing on nitrogen cycling in soils beneath Stipa tenuis, native to central Argentina

• Published in: Journal of arid environments Vol. 74; no. 3; pp. 419 - 422
• Main Authors: Andrioli, R.J., Distel, R.A., Didoné, N.G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.03.2010; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; biogeochemical cycles; Biological and medical sciences; biomass; Caldenal rangelands; Fundamental and applied biological sciences. Psychology; grassland soils; grasslands; grazing; livestock; Livestock grazing; mineralization; nitrogen content; Nitrogen mineralization; rangelands; roots; Semi-arid rangelands; semiarid soils; Soil inorganic nitrogen; Stipa; Stipa tenuis; Synecology; Terrestrial ecosystems; Argentina; South America; America; Nitrogen mineralization; Soil inorganic nitrogen; Livestock grazing; Semi-arid rangelands; Caldenal rangelands; Monocotyledones; Arid environment; Browsing; Soils; Nitrogen cycle; Inorganic nitrogen; Gramineae; Mineralization; Semi arid zone; Angiospermae; Rangeland; Spermatophyta; Livestock; Native species
• ISSN: 0140-1963; 1095-922X
• DOI: 10.1016/j.jaridenv.2009.09.010

Direct effects of herbivores on plants and on the physical environment can accelerate inorganic nitrogen (N) flow in grassland ecosystems. This study compares N content and N mineralization in the soil beneath plants of Stipa tenuis growing in adjacent grazed or ungrazed areas at three sites in central Argentina. Grazed areas had a long history of heavy, year-long grazing by cattle (6–8 ha cattle −1), whereas ungrazed areas had been excluded from grazing by large herbivore for five to ten years. N content and N mineralization was measured in the soil under plants ( n = 10 per grazing treatment and per site) of the studied species at monthly intervals along an annual growing cycle. N mineralization was measured both in situ and in laboratory under optimal conditions of moisture and temperature. We did not found a significant effect of grazing on N content or on N mineralization in the soil beneath S. tenuis all over the studied period. Sustained, long-term overgrazing by domestic livestock, through plant and soil deterioration may either counterbalance or override accelerating N cycling attributed to prudent grazing (i.e., grazing that favours plant productivity and persistence) in managed grasslands.