Interactive effects of soil amendments and depth of incorporation on Geyerwillow

A greenhouse study was initiated to determine the effect that depth of inco rporation of soil amendments had on growth of Geyer willow(Salix geyeriana Andersson) planted in fluvial mine tailing. Lysimeters were constructed to simulate a 60-cm tailing profile,vith a static water table established at a depth of 62 ca The amendment treatments (lime, organic matter, and lime pl us organic matter) were each applied at three depths of incorporation (0-20 , 0-10, and 0-60 cm). Aboveground current-year's growth (CYG) from widow cu ttings grown in treatments that contained lime was more than eightfold grea ter than that from willows grown in treatments that did not contain lime. W illows grown in the 0- to 60-cm treatments produced 36% more aboveground CY G than those grown in 0- to 20-cm treatments and 27% more than those grown in the 0- to la-em treatments. Belowground CYG, averaged across all amendme nt treatments, also increased with depth of incorporation. Chemical analyse s of the growth media indicated that the lime amendment increased pH of the mine tailing such that trace metals were made less bioavailable and, there fore, not phytotoxic. The addition of organic matter to the lime amendment proved to be beneficial for plant growth and reduced bioavailability of som e metals Widows from all treatments accumulated high concentrations of the metals Cd and Zn in aboveground CYG, Results from this study suggest that i ncreased depth of incorporation of soil amendments into mine tailing can si gnificantly enhance vegetative production of willow cuttings.