Effect of the stocking rate and land slope on nitrogen losses to water on a grazed pasture of southern chile

• F Salazar ^[1] ; M Alfaro ^[1] ; S Ledgard ^[2] ; S Iraira ^[1] ; N Teuber ^[1] ; L Ramírez ^[1]
  1. [1] INIA Remehue
  2. [2] AgResearch, Ruakura Research Centre
• Localización: Journal of soil science and plant nutrition, ISSN-e 0718-9516, ISSN 0718-9508, Vol. 11, Nº. 2, 2011, págs. 97-108
• Idioma: inglés
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• Resumen

  • Most of the studies on nitrogen (N) leaching have been carried out on cut grass, and there is a lack of information on beef grazed grasslands. The objective of this study was to quantify N runoff and leaching losses in beef production systems with two different immediate stocking rates (63 and 191 Holstein Friesian steers ha-1 day-1) and two land slopes (4 and 12%). Runoff and leachate samples were analyzed from 2004 to 2006 for total N, nitrate and ammonium. No significant differences for the total N losses were found between treatments (p > 0.05), which were low ranging from 0.9 to 26.8 kg N ha-1 yr-1. The main pathway for the losses was leaching, which contributed >99% of the total N lost. The main form of N leaching was nitrate-N (>84%). Nitrate-N concentration in runoff samples was high, averaging 14 to 31 mg L-1. We suggest that these low N losses could be related the low N fertiliser inputs in the pasture and to the N adsorption properties of volcanic soils and, so that further research is required on this subject.