Journal of Agricultural Research 



Vol. V. No. I 



TABtE III. — Quantity of dry matter {in grams) produced by wheat and sugar-beet plants 

 raised in soil containing alkali salts in various concentrations 



While the data in the tables are somewhat irregular on account of the 

 comparatively small number of plants used, a few facts come out rather 

 clearly. Probably the most conspicuous of these is the relatively high 

 toxicity of sodium chlorid (NaCl) in Greenville soil when compared with 

 other salts. 



Two thousand p. p. m., or 0.2 per cent, marked the limit of growth 

 for wheat, while three thousand p. p. ra. was the limit for sugar beets. 

 There was germination and growth with considerably more sodium car- 

 bonate (NaoCOg) than sodium chlorid, although the carbonate dissolved 

 the organic matter from the soil, producing a very bad physical condition. 

 Magnesium sulphate (MgS04) was only slightly toxic at a concentration 

 of I per cent of the soil, while sodium sulphate (Na2S04) was more toxic, 

 but produced fair crops where i per cent was present. The percentage 

 of germination, the height of plants, and the dry weight all correspond in 

 showing where the growth began to be retarded by salt. 



In order to determine the effect of the percentage of soil moisture on 

 the toxicity of alkali, tests were made with soils having 12.5, 15, 17.5, 

 20, 22.5, 25, 27.5, and 30 per cent of water on the dry basis. At the 

 one extreme the soil was about as dry as plants would grow in, while at 

 the other it was completely saturated. The soil used was Greenville 

 loam, and the seed planted was New Zealand wheat. The methods 

 were the same as those already described, with 10 seeds in each glass. 



The seeds were planted on August 16 and the plants harvested on 

 September 27. The results are shown in Table IV. 



