Accumulation of fertilizer-derived fluorine (F) in pasture soils and its risk to livestock
Analysis of pasture soils with long-term phosphorus (P) fertilizer application histories showed that increased rate of P application caused fertilizer derived F to accumulate in the topsoil (0-75mm depth). Grazing livestock ingest large quantities of topsoil during the wetter months of winter and early spring but less in drier months when pasture covers are greater. If topsoil having elevated F concentration is ingested, livestock could suffer from chronic fluorosis. An indoor soil F feeding trial on young sheep designed to simulate high soil ingestion during one winter season showed that F intake by the animals markedly increased bone F concentrations, though the increased concentrations are below the threshold F concentration above which teeth and bone abnormalities could occur, Other studies on the effect of temporal changes in soil F ingestion on bone F concentration showed that when soil F intake was low some of the bone F, which was accumulated from previous periods of high soil F intake, is mobilized and excreted in the urine. It was concluded from the above studies that with the current topsoil F concentrations in New Zealand the potential risk of chronic fluorosis in young sheep during one year of grazing period is very low. Studies on longer term grazing effects are in progress.
fluorosis livestock phosphate fertilizer sheep soil fluorine
P. Loganathan N. D. Grace M. J. Hedley
Fertilizer and Lime Research Centre, Institute of Natural Resources, Massey University, Palmerston N AgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New Zealand
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
635-636
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）