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| Alfaro,Marta; Salazar,Francisco. |
| In developed countries, intensive grazing has been related to water pollution. The results of several projects carried out on a volcanic soil of the Osorno soil series on beef grazing production systems have shown that grazing management did not increase total nitrogen (N) and phosphorus (P) transfer and losses. Due to the high water infiltration capacity of the soil, runoff was <1% of total drainage, therefore, N and P losses in runoff were small. Nitrogen leaching losses were high (3 up to 71 kg N ha-1 yr-1). Nitrogen loss in runoff was mainly lost as DON (c. 50%) while N leaching losses were mainly as nitrate (c. 70%). Total P losses ranged between 1 and 22 g P ha-1 yr-1 and they increased with increasing field slopes. Phosphorus was mainly lost as... |
| Tipo: Journal article |
Palavras-chave: Nitrogen; Phosphorus; Dairy production; Beef production; Environmental impact. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000200002 |
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| Salazar,Francisco; Dumont,Juan Carlos; Chadwick,David; Saldaña,Rodolfo; Santana,Mabel. |
| In this study 50 slurry samples were collected from commercial dairy farms located in the South of Chile during 1995-1997. Samples were analyzed for dry matter, pH, organic matter, available and total macro nutrients (nitrogen, phosphorus, potassium, calcium, magnesium and sodium), available and total micro nutrients (zinc, iron, manganese and copper) and total aluminum. Results showed that the dry matter content in dairy effluents was low, with 62% of the samples being < 4% DM. This reflected the large volumes of water that the storage received. A great variation in nutrient content was observed in the analyzed samples, probably reflecting differences in feeding regimes, use of wash water, rainfall and age of slurry at the time of sampling. In general,... |
| Tipo: Journal article |
Palavras-chave: Nutrients; Dairy effluents; Cattle slurry; Farm waste. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-28072007000200005 |
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| Alfaro,Marta; Salazar,Francisco. |
| Producto de los tratados de libre comercio firmados por Chile, que auguran la apertura de mercados para la exportación de productos lácteos y cárnicos, se espera que la actividad ganadera del Sur del país se incremente e intensifique. A pesar del conocimiento técnico disponible para el incremento de la productividad del rubro, poco se sabe con certeza sobre el impacto ambiental de esta actividad, en especial sobre cursos de agua, a pesar de que los ríos y lagos de la región son además la base de otras actividades económicas de importancia, como la acuicultura y el turismo. En países desarrollados se ha demostrado que existe una fuerte relación causa-efecto entre la actividad ganadera y la polución difusa de cursos de agua superficiales, en especial de su... |
| Tipo: Journal article |
Palavras-chave: Nitrógeno; Fósforo; Producción de leche; Producción de carne; Impacto ambiental. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-28072005000300012 |
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| Alfaro,Marta; Salazar,Francisco; Iraira,Sergio; Teuber,Nolberto; Villarroel,Dagoberto; Ramírez,Luis. |
| 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... |
| Tipo: Journal article |
Palavras-chave: Eutrofication; Water quality; Grazing; Andisol; Beef production. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000200004 |
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