Nov.4,i9i8 Soil Factors Affecting the Toxicity of Alkali 299 



of sifted peat was added to each. In this case only four concentrations 

 of the salt were used and there were four duplicates of each treatment. 



DoCI inp.p.m.of drysoil 



0^ ^ 400 ifioo z.ooo 3.000 ^00 



no ~ ' ' 



peat 



peat 



5% 

 peat 



lOf. 

 pear 



psaT 



•= one. plant ■ = o-igm-dry motltr 



DoiCOjin p.p.m.afdrYSoil 

 500 ifioo j.ooo sfioo i;ooo 10000 



M'r ©©©©COCXX)OCO 



IS% 

 peat 



JZ0% 



peaT 



t'' one plant mmmmm =x o,ip/n- dry matter 



riOzSO., in p.p. m. of dry 5 oil 



soo 1.000 3.000 5.000 7.000 lopoo 



no 

 peat 



peat 



5% 

 peat 



10% 

 beat 



peat 



so% 

 peat 



• = one plant ^*^^ = a.igiyt- dry matter 



Fig. 12. — DiaKram showing the number of wheat plants up and the dry matter produced in 21 days in 

 sand with different amounts of peat containing sodium chlorid, sodium carbonate, and sodium sulphate 

 added in various concentrations. Soils r.aiutaincd at an equivalent moisture content. 



These were averaged. The results are given in Tables I and II. These 

 tables show that without the organic matter the heaxder soils are more 



