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22 <br />As in previous tests the germination of seeds varied broadly and compari- <br />son of results was best made by comparing survival of plants at the conclusioi <br />of 10 weeks. This comparison showed that the overall germination for all <br />three seeds in the pelleted tailing test was 68 percent with a survival rate <br />of 54 percent, Germination and survival rates for the specific seeds, in <br />percent, were respectively, wheatgrass 78-70, alfalfa 63-46, and rye 63-46. <br />At the 10-week time interval, few differences existed in the survival of <br />plants in the 4-1/2- and 16-1 /2-inch-deep buried sludge layer plots or betweei <br />the two chemicals used to make the pellets. However, visual inspection of th <br />surviving plants showed markedly better plant growth for the shallower layer <br />and for the Coherex binder. <br />All plots reported on in tables 2 through 4 were maintained for at least <br />a 10-week interval and the results are compared in table 5. <br />TABLE 5. -Comparison of overall QerminaEion and <br /> <br />Plant No sludge added Sludge mixed in top <br />3 inches of tailin s Sludge mixed <br />into ellets <br /> Germi- Sur- Germi- Sur- Germi- Sur <br /> nations vivall nation vival nation viva <br />Crested wheatgrass...... 71 28 81 30 78 70 <br />Ranger alfalfa.......... 72 7 51 7 63 46 <br />Rye grain ............... 87 33 76 58 63 46 <br />Overall ................. 77 23 69 32 68 54 <br />`Germination rate at 2 weeks after planting and the survival oL plants atter <br />10-week growth. <br />The comparison clearly shows an advantage for,the addition of sludge to <br />the tailings, particularly in.pelletized form. The pelleted plots were main- <br />tained for a 10-month period before dismantling, and despite daily waterings <br />for the first month and twice weekly watering thereafter, the bulk of the <br />pellets were still coherent. The surface pellets had decrepitated to some <br />extent, but those immediately under the surface retained their cohesive <br />pelleted .forms for the entire period. <br />Combination of Pelletization and Buried Organic Layers <br />A series of tests employing a combination of buried organic layers <br />together with pelleted surface materials was established to determine the <br />effects upon vegetative growth and pH values of the component materials. Foy <br />plots were established using Kennecott tailings that had a pH of 7.8 when <br />first obtained but which had decreased to a pH of 6.6 after several months' <br />storage. Two replicate plots were established with a 2-inch sewage sludge <br />layer placed under 15 inches of tailings capped by a 1-1/2-inch layer compose <br />of, in percent, tailing 92.4, sludge 6.6, and chemical binder 1.0. The seco <br />two replicate plots were the same, except that the 2-inch sewage sludge Jaye <br />was placed under 3 inches of tailings and capped by pellets. <br />