Oct. 4, 191S 



Effect of Alkali Salts in Soils on Crops 



17 



With the carbonates shown in figure 6 there is a marked falling ofiF 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 



VBtSO. 



K.5G, 



(oooppm 



M^SOt 



zfiooppm. 



3.oooppm. 

 CMcK^NoSalt 



Aoooppn. 



s.oooppm. 



6,oooppm loooppm. aoooppn. ^oooppm. iQ.oooppm. 



. = One plant. — = 0.1 gm. dry matter. 

 Fig. s- — 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 (NHJ2C03(NH4)C02NH2 instead of the shorter formula, 

 (NH4)2C03, 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 

 K,cp, 



i^»^m,,ooopp„,^"^o, 



Mooppm. zopopptn. eoooppn, toooppm laoooppm 



. = 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 CO3 part of the compound. 

 It is a well-known fact that protoplasm is very sensitive to the action of 

 free ammonia. 



