Laserfiche WebLink
.: ~ ~ - <br />s <br />Silts, Phytotoxicants, and Fertilization - <br />`1ir.cr cuznti=ies cf soluble beau}• metal salts of copper, lead, zinc, - <br />-__ _ C'n _O^;i •,:-;~ ___ -i ;~ r„i n._ral L:a5CE5 Can aCt a5 D \'tGLOxicants t0 plants <br />~_ce:r. :~:~r~on. Otter salts, while perhaps not having speci`ic toxic effects - <br />_- -~__.. can crecent grri:th b;• producing a high osmotic concentration in `-. <br />t'~e scil solution. Ic?roper use of fertilizers can augment the influence of <br />r;,totesicanes or othar salts by adding to salt concentration or by solubili- _ <br />zation of toxic minerals. therefore, investigations were made of the content - <br />of salts and soluble toxic minerals prior to selecting the fertilizers to be _ <br />applied. These studies demonstrated that neither salts nor phytotoxicants <br />l•:=_re .^..aor problems ~•:ith the particular tailings sample being tested. Prelim- <br />inar~• *_esting also indicated that potassium was not necessary for attaining _ <br />~atiSf aCtOr\' growth. <br />~fter preliminary' consideration of salinity and phytotoxicant effects, - <br />othar vegetative plots were established with various amounts and types of <br />nitrcgenous and phesahztic fertilizers to select the preferred fertilization -" <br />regir.:e. Many of the common fertilizer combinations, such as 6-10-4 and <br />16-16-& N-P-K, ware eliminzted from testing because potassium (K) was not - <br />needed. Nitrogen in amounts varying from 30 to 100 pounds per acre of tail- ~' <br />inns was added in the form of ammonium sulfate, ammonium nitrate, and urea. -_- <br />Siilar amounts of phosphorus, calculzted as P20g were added as calcium super- <br />pho<_p::ate or calcium treble superphosphate. Laboratory testing indicated that <br />prilled urea and calcium treble superphosphate in quantities equal to 45 <br />pounds per acre each of nitrogen and P20~ would be satisfactory fertilizer <br />amendments to be added to the field test seeding mixture. <br />Structure <br />Several methods were tested in the laboratory for changing the structure _-_ <br />of the P;cGill tailings to improve solid, water, and air relationships, thereby _ <br />enhancing vegetative growth. Compost made .from municipal refuse and sewage <br />sludges was tried to simultaneously improve the structure and to add organic <br />matter. Plots prepared with the copper tailings and 5 tons per acre of each <br />of the two waste-derived products indicated the additives to.:be beneficial to <br />both vegetative germination and growth. The sewage sludge produced better <br />growth than the commercial compost and would be the preferred amendment if <br />costs were disregarded. The addition of fertilizer to the compost and sludge ' <br />produced still better growth. <br />A second method employed to improve the structure of the tailings was '- <br />- pelletizing or agglomerating the tailings particles comprising the surface la.- <br />ars of the growth plots. The first procedure tested consisted of pelletizing <br />tailings to minus 8- plus 35-mesh with 2.5 percent asph2lt, hardening the pel- <br />lets by baking at 250° C, and spreading the pellets over the surface of the <br />=eilings to z depth of 1/2 inch or mixing the pellets eaich zn equal quantity <br />G tildngs to form z 1-inch-dee.p covering over normal tailings. ~ similar <br />-___~_ ::zs achieved, s;ityout the baking step, by pelletizing with 3 to 4 <br />