408 Thirtieth Annual Report 



COTTON TOLERANCE TO ALKALI IN FIELD 

 In the Twenty-ninth Annual Report of this Station are reported 

 several analyses of alkaline soil showing different degrees of dam- 

 age to crops in the field. Similar observations have recently been 

 made by Mr. Catlin on cotton in Salt River Valley. Here again the 

 difficulty of securing soil samples representing the actual conditions 

 under which the crop is growing are almost insurmountable. The 

 results of this investigation will be found in Table III. Other data 

 for alkali resistance by cotton are given by Nos.7366, 7367, and 7368, 

 Table II. None of the failures can be attributed definitely to black 

 alkali but seem to be due to soluble salts and chlorides. These re- 

 sults in a general way show good cotton produced on soil contain- 

 ing .4 percent soluble salts with low chlorides ; stunted, unprofitable 

 cotton on soils containing .4 to .6 percent soluble salts with .1 to .3 

 percent chlorides; and total destruction of the crop on soils con- 

 taining upwards of .6 percent soluble salts of which one-half or 

 more was chlorides. The relatively high tolerance on No. 7627 

 cannot be accounted for; it may have been due to rise of alkali late 

 in the season. 



