Nov. 4. 1918 Soil Factors Affecting the Toxicity of Alkali 



303 



EFFECT OF ORGANIC MATTER 



Another factor to be studied separately was the effect of the organic 

 matter of the soil on the toxicity of the alkali. The results given above 



PaCI in pp-m-ofdrysoil 

 400 (,000 g.ooo 3.000 4^,000 



DO /^^»^/'»*«^/''*^ /»*^/' 



peat 

 peat 



10% 



jjeat 



20% /^;s^/^^/ss ^^-<^^^/^ -iv?>^/^ 



• = onepiont «»»=»» = oi^m dry matter 

 r)a^C0jinp.p.ir\.ofdrY5oil 



300 1.000 JjOOO S.000 7.000 10X100 



pear '^^^^^^^^A^^ly^zJy^ziT^^ 



ZXtV. — ~ — ~ 



peat 



peat 



peat 



peaT 



• = one plant •"•^^ = o-ifm- dry matter 



Ho. 50^ in p.p.trr\-ofdr\{SQil 



500 1,000 J.OOO 5,000 2000 10,000 



2)i ?f /^e*i\ /^*i^ /9o if\ /^C9^ /•Zm\ /•••^ / ^m»^ ^•N /C*o^ / 



peat 

 pear 



isy, 



peat 



20'/. 



peat 



• = one plant 1 = oijrri. dry matter 



Fig. 15. — Diagram showing the number of heat plants up and the dry matter produced in loam with 

 different amounts of peat containing sodium chlorid, sodium carbonate, and sodium sulpliate added in 

 various concentrations. Soils maintained at an equivalent moisture content. 



seem to indicate quite strikingly that organic matter increases tolerance. 

 Several series of experiments were conducted to show the effect of a rich 



