WATER ROILS. 547 



Sdnia silt loam), Upper Marlboro, Md. (Norfolk sand and sassafras loam), Lancaster, 

 Pa. (Hagerstown clay loam and Hagerstown loam), and Janesville, Wis. (Janesville 

 loam and Miami loam). Soils were selected which were "strongly contrasted in 

 their native productive capacities in order that strongly marked differences might 

 be dealt with." 



The crops grown were corn and potatoes. The yields of the crops, generally in 

 both green and dry state, are recorded, as are studies of the water-soluble salts of the 

 soils before and at intervals during the experiments. The plant juices were also 

 studied with a view to ascertaining the relations between the soil solutions and the 

 substances taken up by the crops. Care was taken to secure manure of uniform 

 quality for use on the two soil types in each locality, but analyses of the manure are 

 not given. 



The results of the experiments with corn show in general that both relatively and 

 absolutely the fertilizers had a greater effect on the poorer soils than on the stronger. 

 With the poorer soils there was "a systematic difference in the yield of water-free 

 shelled corn, closely related to the fertilizers applied to the soil. The group of four 

 stronger soils did not show, throughout, this systematic relation." The experiments 

 with potatoes yielded practically the same results as those with corn. 



From the results of analyses of the leachingsof the soils on which the experiments 

 were made, "it is very clear that the effect of different amounts of stable manure 

 applied to these soils . . . was such upon the recovery of the water-soluble salts as 

 to enable the same treatment to remove different amounts from different fertiliza- 

 tions. . . . There is a clear quantitative relation, too, between the yields and the 

 salts recovered, these (the former) increasing where the essential ingredients of plant 

 food are higher." Four-pound samples of the soils mixed with comparatively large 

 amounts of manure gave when leached after 65 days results agreeing in general with 

 those obtained in the field tests. 



The examinations of the plant juices showed that the manuring had a direct effect 

 upon the water-soluble salts taken up by the plants. " It is thus shown that the crops 

 on the manured ground recovered 29 per cent more potash from the four stronger 

 soils, and 40 percent more from the poorer soils, where the 15 tons of manure had 

 been applied." On the other hand, lime and magnesia decreased where the potash 

 increased. 



Summarizing his results the author says: "The observations here presented, both 

 upon the soils and upon the plants which had grown upon them, make it clear that 

 when farmyard manure is applied to fields it has the effect not only of increasing the 

 yields, but at the same time of increasing the amounts of water-soluble salts which 

 can be recovered from the soils themselves and from the plants which have grown 

 upon them." 



F—The movement of water-soluble salts in soils (pp. 62-113). — The studies here 

 reported were made on a number of type soils in galvanized-iron cylinders "pro- 

 vided with reservoirs at their bases which permitted the addition of water at the 

 bottom of the columns and its rise by capillarity through the soil." The soils were 

 removed at intervals in 2-in. sections and analyzed. The rise of capillary water 

 increased the total soluble salts in the soils, the sulphates, nitrates, and chloride 

 accumulating in large amounts in the surface 2 in. The phosphates were not 

 materially affected. 



Field observations are cited to show the tendency of soluble salts to accumulate by 

 "capillary sweeping" under rows of crops, especially in furrow irrigation and ridge 

 culture. 



In a series of experiments with the 8 type soils used in the experiments with manure 

 noted above, a solution of salts was used in the reservoirs of the cylinders and their 

 movement by capillarity studied. 



