Oct. 4, 1915 
Effect of Alkali Salts in Soils on Crops 
17 
With the carbonates shown in figure 6 there is a marked falling off with 
the ammonium carbonate above 5,000 p. p. m. With the others there is 
a good germination up to 10,000 p. p. m., similar to the results shown in 
figure 2. The formula given by the manufacturers of the ammonium 
K^toooppmW 0 * 2,000ppm. 
zoooppm. 
Ajoooppm. 
Chea@NoSait 
s.oooppm. 
t,ooo ppm. 1000 ppm. &000 ppm. 4000 ppm. 10,000 ppm. 
• == One plant — = 0.1 gm. dry matter . 
Fig. 5.—Diagram showing the number of wheat plants up and dry matter produced in 24 days on Green¬ 
ville loam with potassium sulphate, magnesium sulphate, and sodium sulphate in different combinations 
and concentrations. 
carbonate was (NH 4 ) 2 C 0 3 (NH 4 )C 0 2 NH 2 instead of the shorter formula, 
(NH 4 ) 2 C 0 8 , given on the figures. 
It is probable that the toxicity of the ammonium carbonate was due, 
in part at least, to the free ammonia that was constantly being given off 
Checkoff) Ho San 
ofiooppm^ lopoppnt 4000 ppm, 9000 ppm w. 000 ppm. 
• = One plant. — ~ 0.1 gm. dry matter. 
Fig. 6.—Diagram showing the number of wheat plants up and dry matter produced in 24 days on Green¬ 
ville loam with ammonium carbonate, sodium carbonate, and potassium carbonate in different combina¬ 
tions and concentrations. 
by this unstable compound rather than to the C0 3 part of the compound. 
It is a well-known fact that protoplasm is very sensitive to the action of 
free ammonia. 
