298 



Journal of Agricultural Research 



Vol. XV, No. s 



In order to eliminate the effect of the organic matter which was pres- 

 ent in the loam and not in the other soils, two series were conducted, 



DoCI in p.p. m. of dry soil 

 400 1.000 2.000 jooo 



4.000 



ho 

 garden soil 



garden soil ' 



garden soil 



10% 



garden soil 



15% 

 garden soil 



garden soil 



one plant 



0,1 <)m. dry matter 



HojCDj inp.p.m.ofdryso/l 



500 1,000 2,0 00 S,000 7000 



xo% 

 garden ioil 



10,000 



*=one plant 



-^ 0.1 gm. dry motter 



7.000 



I^OxSO.^ in p.p. m. of dry soil 



500 1.000 3.000 5000 



no /^^ ^.'iii*^/i^r is<iih. 

 garden soil 



garden sod 



garden soif 



10000 



garden soil 





!0% 



garden soil 



one plant 



■I jm-dry matter 



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

 sand with different amounts of garden soil containing sodium chlorid, sodiimi carbonate, and sodium 

 sulphate added in various concentrations. Soils maintained at an equivalent moisture content. 



using, only mixtures of clay and sand at an equivalent moisture content. 

 In one series no organic matter was added, and in the other lo per cent 



