Study the effects of altitude and slope characteristics on minerals content in rangeland soil, plants and sheep milk (Case study: north and southeast Sabalan in Ardabil province)

The aim of this study was to determine and compare the mineral concentration in the milk of grazing ewes in rangelands of northern and southeastern Sabalan. For this purpose, three range sites in 1800-2100, 2300-2700 and 3200-3700 meter from sea level in the rangeland of south-eastern Sabalan and 1300-1800, 1800-25800 and 2500 3200 m elevations in northern Sabalan were selected as the study site. Soil samples were collected and plant biomass in a 1 m2 were measured and grazed sheep milk grazed in these sites were collected for the measurement of mineral concentrations. The minerals concentrations of Calcium, Phosphorus, Potassium, Magnesium, Sodium, Zinc, Copper, Manganese and Iron in collected samples were measured by atomic absorption spectrophotometer and flame photometer. Data was analyzed in a completely randomized design using SAS9.1 software and the General Linear Model procedure was used for statistical analysis. The results showed that Ca (619.49 mg/kg), P (607.41 mg/kg), K (1399.29 mg/kg), Mg (165.01 mg/kg), Cu (1312.9 μg/kg), Zn (10920 μg/kg) and Mn (732.6 μg/kg) in grazing sheep milk in the site of 1300-1800 m of south-eastern Sabalan were significantly higher (P<0.05). Ca (937.57 mg/kg), P (320.55 mg/kg), Na 924.75 mg/kg), Mg (100.05 mg/kg), Fe (24041 μg/kg), Cu (2384.7 μg/kg) and Mn 1355.79 μg/kg) in grazing sheep milk at 2500-3200m elevation of northern Sabalan were significantly higher (P<0.05). According to the results, of most elements except calcium, copper and manganese in milk of grazed sheep in rangelands of south-eastern Sabalan were significantly higher (P<0.05) than the sheep grazed on northern slopes.. In general, the results showed that the ecological conditions such as altitude and aspect of rangelands has great influence on mineral concentration of sheep milk in Sabalan through their effets on the soil and plant minerals.