1916] Sharp : Soluble Salts and Soil Colloids 295 



calculated and applied on the basis of percentage of weight of 

 the five-foot column of soil in every cylinder. 



As mentioned above, all of the salt-treated soils developed 

 every indication of a thoroughly diffused condition. As a result, 

 percolation through the treated cylinders practically ceased, so 

 that the rain-water collected in the two-inch cylinder rim and 

 remained so persistently as to prove seriously detrimental to the 



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Fig. 1. The Salt and Manure Applications to the Soil in the 



Cylinders at Davis. 



The upper figures refer to the percentages of salts in the 5-foot 



column of soil. The lower figures refer to the grams of barnyard manure 



added. In row 1, no. 1 contains Na^SO^ instead of NaCl. In row 10, no. 



2 likewise contains NaaSOi instead of NaoCOs. 



growth of crops. As a final measure, holes were opened down 

 through the soil columns to provide drainage. In sharp contrast 

 with the treated soils, even immediately after heavy rain-storms, 

 no standing water was ever observed on the control soils, and 

 the splendid growth of the crops planted on them showed a con- 

 genial condition for crop development. Both the winters of 



