Data/hora: 09/06/2024 06:31:00

Provedor de dados: 	Chilean Journal of Agricultural Research	
País: 	Chile	
Título: 	Nitrogen, Phosphorus and Potassium Losses in a Grazing System with Different Stocking Rates in a Volcanic Soil	
Autores: 	Alfaro,Marta; Salazar,Francisco; Iraira,Sergio; Teuber,Nolberto; Villarroel,Dagoberto; Ramírez,Luis.	
Data: 	2008-06-01	
Ano: 	2008	
Palavras-chave: 	Eutrofication; Water quality; Grazing; Andisol; Beef production.	
Resumo: 	In Chile there is little information on nutrient losses in livestock systems. The experiment was carried out between 2004 and 2006. Two stocking rates (3.5 and 5.0 steers ha-1) were tested under rotational grazing with Black and White Friesian steers on a permanent pasture (67.5 kg N and 40 kg P ha-1 yr-1). To quantify surface runoff losses (N, P, K), three surface lysimeters (5 x 5 m) per treatment were established. N and K leaching losses were estimated with ceramic cups. Runoff and leachate samples were individually analyzed for available and total N, reactive (RP) and total P, and K. Dissolved organic N (DON) and organic P (OP) were estimated as the difference between total and available forms. The stocking rate did not increase total N, P and K losses (P &gt; 0.05). Losses in surface runoff were &lt; 0.5 kg N, &lt; 0.05 kg P and &lt; 0.6 kg K ha-1 yr-1, respectively, due to the low amount of runoff measured. Nitrogen leaching losses were high (11 up to 71 kg ha-1 yr-1) and K leaching losses were low (3 to 5 kg ha-1 yr-1). Nitrogen in runoff was mainly lost as DON (50%). Nitrogen leaching losses were mainly as nitrate (70%). Phosphorus was lost as RP (70%). Thus, stocking rates of 5.0 steers ha-1 are plausible, but fertilizer application should be avoided in rainfall periods during the year to reduce incidental nutrient losses.	
Tipo: 	Journal article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000200004	
Editor: 	Instituto de Investigaciones Agropecuarias, INIA	
Formato: 	text/html	
Fonte: 	Chilean journal of agricultural research  v.68 n.2 2008