Oct. i, 1920 



Cause of Lime-Induced Chlorosis 



45 



The plants in the soils containing sodium bicarbonate became some- 

 what yellow, though the yellowing was not that of typical lime-induced 

 chlorosis. The yellowing, however, was not increased by the lime spray, 

 nor was it overcome by the iron spray. The lime and iron sprays also 

 had no effect on the appearance of the plants growing in the soil con- 

 taining no sodium bicarbonate. 



Experiment VI. — In this test, conducted from November 4, 1913, to 

 March 12, 1914, 7 rice plants were grown per pot. Each pot contained 

 35 pounds of sandy soil and received 6 gm. ammonium nitrate, 1.3 gm. 

 potassium acid phosphate, and 2.5 gm. potassium sulphate. The mois- 

 ture content was maintained at 25 per cent of the dry weight of the soil. 

 The results are shown in Table VIII. 



Table VIII.- 



-Effect of sodium bicarbonate, lime, and iron on the growth of rice: 

 Experiment VI 



The appearance of the plants in this test was the same as in experi- 

 ment V. 



The plants from experiment V were analyzed for their ash constituents, 

 and the results appear in Table IX. The plants were washed imme- 

 diately after cutting, so no lime salts remained on the leaves. While it 

 . s believed that all iron applied as a spray was also removed by washing, 

 it is possible that some iron in the form of ferric oxid might have remained 

 adhering to the leaves; hence, in the case of the plants sprayed with 

 ferrous sulphate, it is possible that the analytical results may show more 

 iron than was actually present in the plants. 



