14 The Effects of Radio- Active Ores and Residues on Plant Life. 



EXPERIMENTS WITH RAPE SEED TO 

 ASCERTAIN EFFECT ON GERMINATION 



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1 " Control " 

 plain soil only. 



One part Residue 

 to 448 parts soil. 



One part Ore 

 to II* parts soil. 



Some of the Tests with Rape seed. It will be seen that in the boxes dressed respectively with 

 Residue and Ore, growth is much more luxuriant than in the "Control" box. 



In order to further ascertain the effects of radio-active Ores and Residues 

 on germination, small boxes were sown with seed of Rape, one of the quickest 

 germinating subjects. No artificial heat was applied, the boxes being stood 

 in a cold frame. 



The proportions of Ore and Residue used are stated in the table below : 



Control Plain soil only. 



Farmyard Manure (at 15 tons per acre) added to soil. 

 Guano (at about i oz. per sq. yard) added to soil. 

 Complete Fertiliser (at about 3 ozs. per sq. yard) added to soil, 

 part Ore in 14 parts of soil. 

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The trials were carried out in duplicate, the second sowing being made 

 five days after the first. The results of the first experiment were in all 

 cases confirmed by those of the second. It was found that in each of the boxes 

 dressed with Ore or Residue the seed germinated before that in the plain-soil 

 " control " or in the boxes dressed with manures. Further, all the radio- 

 active soil tests germinated equally, except " Ore i in 14," which probably 

 indicates that the proportion was too great. Next in order of germination 

 came the plain soil, farmyard manure, complete fertiliser, and guano last. 

 After three weeks' growth it was still noticeable that those trials dressed 

 with artificial manures were the most backward. 



The experiment is extremely interesting in that it shows, so far as hastening 

 germination is concerned, the dressing of Residue (containing i'8 of -Radium 

 Bromide per ton) at the rate of i Ib. to i ton of soil, gave results equal to the 

 dressing of Ore (containing approximately 9 milligrammes of Radium Bromide 

 per ton) at the rate of i Ib. to 14 Ibs. of soil, the latter costing many times 

 as much as the former. 



