288 Journal of Agricultural Research voi. xv. no. s 



tumblers were made up to weight with distilled water as often as the loss 

 became appreciable. On the twenty-first day after planting, the crop 

 was harvested by cutting the plants at the surface of the. ground with 

 small scissors. The height of each plant and the number of leaves were 



DaCl in p.p.m- of dry soil 



^00 1.000 2P00 3,000 ^.000 



sand 



2 to J mm. 



3ond 



3 to S mm 



sand 



Siol mm 



sand 



ItofO mm- 



sond 



• = one plant ^■^~ =^ o-i^m dry matter 

 nOjCOj in p. p.m. of dry so// 



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sond 



iitoS mm- 



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sand 



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 5 and 



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DOiSO^f Inp-p-mofdrysoil 



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 sand 'K^J/^_y<^^^''^Ziy<it 



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Fig. I.— Diagram showing the number of wheat plants up and the dry matter produced in 21 days in 

 quartz sand of different sizes containing sodium chlorld. Sodium carbonate and sodium sulphate added 

 in various concentrations. iMoisture content maintained at 20 per cent throughout. 



recorded. The plants from each tumbler were placed in an envelope 

 and dried in an oven, and the dry weight was determined. The 3-week 

 period was arbitrarily chosen, because by that time nearly all the plants 

 that would germinate had done so, and the growth ceased to be vigorous. 



