810 EXPERIMENT STATION RECORD. [Vol.35 



in the silt from the humid area, but was somewhat lower in the clay. In 

 both subsoils the amount of soda was highest in the very fine sand and much 

 the lowest in the clay. The dilute acid dissolved about four times as much 

 potash, but only about half as much soda, from the semiarid as from the 

 humid subsoil, but the soluble portions of both form only a small proportion 

 of the total amounts present. On the other hand, the dilute acid removed from 

 both more than half the total phosphoric acid, the proportion dissolved being 

 higher in the semiarid subsoil. In the separates much more phosphoric acid 

 was found in the clay than in the silt and the very find sand, in which it was 

 alike. 



" The most noteworthy differences were shown by treatment with citric acid 

 solution. The potash soluble in this reagent was found to increase with the 

 aridity ; in the most humid areas it decreases from the surface downward, while 

 in the least humid it increases, notwithstanding an accompanying inci'ease in 

 the carbonate content ... In contrast with this, the citric acid-soluble 

 phosphoric acid was found not to increase vpith the aridity, when [considering] 

 the whole 6-ft. section; in the first 2 ft. it increases, but in the lower 4 ft. 

 it decreases from east to west. In the most humid areas it increases rapidly 

 from the surface to a depth of 6 ft., while in the most westerly areas it de- 

 creases. In the latter the difference is to be attributed to the increase in car- 

 bonate content, because when this is neutralized the sixth foot yields as much 

 to the acid as does the first. The high content of citric acid-soluble phosphoric 

 acid is not confined to the lower portion of the 6-ft. sections, but continues to 

 more than twice this depth. ... In content of potash, soda, and phosphoric 

 acid the soils from all the areas resemble the chernozem soils of Russia and 

 the arid soils of California." 



A list of 12 references to literature bearing on the subject is appended. 



The loess soils of the Nebraska portion of the transition region. — IV, 

 Meclianical composition and inorganic constituents, P. J. Alway and G. O. 

 RosT (Soil Sci., 1 (1916), No. 5, pp. ^05-436, figs. ^).— It was found that "the 

 loess soils of the Nebraska portion of the transition region consist chiefly of 

 very fine sand and silt which together constitute from 77 to 95 per cent of the 

 soil mass, the remainder being chiefly clay. From east to west the clay de- 

 creases and the relative proportions of the silt and the very fine sand change, 

 the former decreasing and the latter increasing. The mechanical composition 

 shows no distinct relation to the depth except that the clay content is lower in 

 the first than in the second foot. . . . 



" The samples were subjected to both a complete rock analysis and to 5-day 

 digestion with hydrochloric acid of 1.115 specific gravity. The carbon dioxid, 

 which is present chiefly in calcium carbonate, shows greater variations than any 

 other constituent ; while low in the first 2 ft. of all the areas, the amount in the 

 subsoil increases markedly from east to west. The lime varies widely, both 

 the total and the acid-soluble portion, being three times as high in the western 

 subsoils as in the eastern. The content of magnesia shows no definite relation 

 to that of the lime, in the eastern areas it being as high but in the western 

 much lower ; it is independent of the aridity and, except that it is lowest in 

 the surface foot, also of the depth. The total alumina is very uniformly dis- 

 tributed but in all the areas shows a minimum in the surface foot. The acid- 

 soluble portion is similar in the western four areas, but markedly higher in the 

 eastern two; like the total it is lower in the first than in the second foot. It 

 shows no definite relation to either the clay or the acid-soluble potash. The 

 iron, manganese, and titanium are distinctly higher in the eastern two than in 

 the other four areas. Almost the whole of the iron is acid-soluble ; like the 

 alumina it shows a minimum in the surface foot. The whole of the manganese 



