44 BULLETIN "E." 



of potash, and 1.6 more of phosphoric acid that the unmanured 

 soils did; while the same dressing applied to the poorer soils 

 produced a gain of 7.7 parts of potash and 3.4 parts of phos- 

 phoric acid. When 50 tons of manure were applied the gains 

 were 11.67 and 6 parts for the stronger soils and 16.55 and 

 15.90 parts per million of potash and phosphoric acid for the 

 poorer soils, respectively. When 100 tons of manure are ap- 

 plied the differences then become 20.25 and 19.60 for the 

 stronger soils and 45.85 and 35.30 for the poorer, for the pot- 

 ash and phosphoric acid, respectively, in parts per niillion of 

 the dry soil; while at 200 tons the gains! become enormous, 

 reaching 69.10 and 73.75 for the stronger soils and 109.70 and 

 107.27 for the poorer, of potash and phosphoric acid, respec- 

 tively, in parts per million of the dry soil. 



There is, therefore, abundant proof in these observations 

 that large dressings of manure do increase in a high degree the 

 water-soluble salts which may be recovered from a soil. 



INFLUENCE OF LIME AND STABLE MANURE ON WATER-SOLUBLE 



SALTS IN SOILS. 



In these experiments composite samples of the surface! foot 

 of soil of each type were procured, and after mixing and bring- 

 ing them to good moisture condition each sample was divided 

 into four lots of 15 pounds each, to one of which nothing was 

 added, to another lime at the rate of 1 ton per acre, to another 

 10 tons of air-dry stable manure per acre, and to the fourth 10 

 tons of air-dry manure and 1 ton of lime per acre. The soil? 

 were kept at nearly constant moisture and good aeration condi- 

 tions during a period of about fifty days, at the end of which 

 time the soluble salts were determined, with the results given 

 in the following table: 



