Abstract
Heavy metals, trace elements, pasture and cattle observations from the Upper Hunter mine grazing study.
The Upper Hunter mine grazing study is in its third year and new replacement steers have been introduced at both the Singleton and Muswellbrook sites. The first round of the study which monitors rehabilitated mine land and adjacent native pasture analogue sites showed a link between soil fertility, pasture growth and cattle weight gain. The average value of steers produced on rehabilitated mine land was higher than the average value of steers grazing the native pasture analogue areas. The second round of the study will monitor pastures and cattle to see if these results are repeated. Soils, pastures and cattle were sampled and analysed to measure major nutrients, heavy metals and trace elements. Soil tests showed that heavy metals were well below levels of concern except for nickel which was marginal at one site. Pastures may vary in nutrient levels due to pasture species, growth stage or part of plant tested, growing conditions and time of year. Pasture analysis results were below level of detection on all samples for arsenic, cadmium, lead and selenium. Nickel in pasture samples was in normal range with even the highest test results well below toxicity levels. Zinc results varied widely with some results low and some high. Boron and copper levels were normal to low. Blood samples were taken by a vet from Local Land Services and tested for selenium, lead, copper and zinc. Results were within normal range except for selenium which varied at each site but showed no difference between rehab and analogue at either site.
Heavy metals, trace elements, pasture and cattle observations from the Upper Hunter mine grazing study.
The Upper Hunter mine grazing study is in its third year and new replacement steers have been introduced at both the Singleton and Muswellbrook sites. The first round of the study which monitors rehabilitated mine land and adjacent native pasture analogue sites showed a link between soil fertility, pasture growth and cattle weight gain. The average value of steers produced on rehabilitated mine land was higher than the average value of steers grazing the native pasture analogue areas. The second round of the study will monitor pastures and cattle to see if these results are repeated. Soils, pastures and cattle were sampled and analysed to measure major nutrients, heavy metals and trace elements. Soil tests showed that heavy metals were well below levels of concern except for nickel which was marginal at one site. Pastures may vary in nutrient levels due to pasture species, growth stage or part of plant tested, growing conditions and time of year. Pasture analysis results were below level of detection on all samples for arsenic, cadmium, lead and selenium. Nickel in pasture samples was in normal range with even the highest test results well below toxicity levels. Zinc results varied widely with some results low and some high. Boron and copper levels were normal to low. Blood samples were taken by a vet from Local Land Services and tested for selenium, lead, copper and zinc. Results were within normal range except for selenium which varied at each site but showed no difference between rehab and analogue at either site.
Presentation
Heavy metals, trace elements, pasture and cattle observations from the Upper Hunter mine grazing study.
Presented on 30th March 2017 at the 7th Annual Best Practice Ecological Rehabilitation of Mined Lands Conference (2017)
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