Alfalfa, Medicago sativa L., establishment in mine mill tailings - I. Plant analysis of alfalfa grown on iron and copper tailings

Alfalfa (Medicago sativa L.) cv. Vernal, was established in iron and copper tailings, a mine waste, to observe its growth and development. In tailings, organic matter and nitrogen are essentially nonexistent, phosphorus levels are low (2-4 kg/ha), potassium, calcium, magnesium and metals range in availability, have alkaline pH (7.2-8.3) and low cation exchange capacity (1.03-3.97 meq/100 g). Alfalfa plants were selected in four year old stands for plant analysis pof whole tops and roots. Levels of nitrogen (2.00-2.56% ash), phosphorus (.16-22% ash) and magnesium (.17%-48% ash) in whole tops were considered in a deficiency range. Potassium and calcium levels were sufficient. Levels of metals in whole tops varied with concentrations in the tailings. The highest metal concentration was iron which ranged from a low in whole tops of 961 ppm in tailings having 1925 ppm, to a high of 5347 ppm in tailings with 2562 ppm. Geneally, metal concentrations were higher in roots whereas nutrients such as nitrogen and phosphorus lower than whole tops