MANURE, YIELD AND SOLUBLE SALTS IN SOILS. 



21 



Percentage relations of water-soluble salts recovered from soils 

 receiving 5, 10, and 15 tons of stable manure per acre. 



From this table it is very clear that the effect of the differ- 

 ent amounts of stable manure, applied to these soils, and that 

 of the 300-lbs. of gnano, as well, has been such, upon the recov- 

 erable water-soluble salts, as to enable the same treatment to 

 remove different amounts from each fertilization. 



As a rule, the amounts increase with the amounts of manure 

 added, but how these amounts are related to the amounts car- 

 ried to the soils with the manure cannot be shown, because 

 altered plans have prevented the analyses of the manure and 

 guano used, as had been the intention. There is a clear quan- 

 titative relation, too, between the yields and the salts recovered, 

 these increasing where the essential ingredients of plant food 

 are higher. 



Two of these soils, the Miami Loam and the Norfolk Sand, 

 were subjected to repeated washing with alternate drying be- 

 tween each washing, using samples from the sub-plots to which 

 no manure had been added and from those to which 15 tons 

 had been applied. The results which were secured by this 

 treatment are given in the next table. 



