520 EXPERIMENT STATIOInT RECORD. [Vol.41 



It is concluded then that the action of alliali salt solution, such as sea water 

 on soils, is one resulting in the displacing of the calcium and in less measure 

 the magnesium compounds by the alkalis. The presence of salts with the 

 same cation in the soil solution was found to interfere with the hydrolysis 

 and the consequent splitting off of the alkali hydrate. With the disappear- 

 ance of alkali salts with the common ion, hydrolysis of soil zeolites set in and 

 alkali hydrates were found in the soil solution as shown by displacement of 

 the salt solution by washing. Sodium salts had a more injurious influence than 

 potassium salts, which is attributed partly to a greater power to dissolve 

 humus considered as a protective colloid. 



Permeability experiments using potassium permutit and sodium permutit 

 gave the same results as the alkali chlorid solutions by displacing these solu- 

 tions in soils with water. The permeability of the soil was markedly reduced, 

 and the drainage water was brown and contained considerable clay. The alka- 

 linity was high, and the sodium compound gave the most mnrked results. Addi- 

 tion of a 0.5 per cent solution of common salt stopped the unfavorable action 

 of the sodium permutit, proving the theory noted above. 



The coniparative value of various forms of lim.estone, R. Stewakt and F. A. 

 Wyatt (Soil ScL, 7 (1919), No. 4, pp. 273-278). — Four years' experiments on 

 114 plats and 14 years' experiments on 64 plats, conducted by the Illinois Ex- 

 periment Station to compare high calcium and dolomitic limestones on acid 

 soils, are reported. 



It is concluded that " for the common farm land of acid regions, an ap- 

 plication of 1 ton per acre of limestone once in 3 or 4 years is sufficient to 

 keep the soil alkaline, or sweet, after the initial acidity has been destroyed 

 by heavier applications. Dolomitic limestone can be used successfully on acid 

 soils. It is slightly more effective than high-calcium limestone in neutralizing 

 the soil acidity, is more durable, and has no injurious effects on the crop 

 yields. . . . There is no evidence that finely ground limestone is more effec- 

 tive in correcting soil acidity than is the total product from a |-ln. screen, 

 which contains both the finer material for immediate use and the coarser 

 material for greater durability. . . . 



" Limestone applied to the surface slowly penetrates into the subsurface. 

 This process, however, requires considerable time. On the Odin field after 

 14 years, one-half the acidity in the subsurface was neutralized where the 

 larger applications had been made to the surface, and one-fourth where the 

 lighter applications had been made. Applications of limestone to the surface 

 soil seem to have no effect upon the acidity of the subsoil. The amount of 

 native limestone found in the subsoil is a variable quantity. In some cases 

 there is none present even at a depth of 40 in., whereas in other cases it ex- 

 tends upward even slightly into the subsurface. . . . 



" The annual loss of limestone is not so large as generally assumed. As 

 an average of all determinations, the annual loss from the surface 20 in. was 

 760 lbs. per acre from the Newton field and 542 lbs. per acre from the Odin 

 field. A study of the total calcium indicates that the actual loss of bases may 

 have been less than is shown by these figures, which are based upon the car- 

 bon dioxid and acidity determinations. It is very evident from the data pre- 

 sented that chemical analysis may be depended upon to measure the acidity 

 in the soil, the reduction in acidity due to the action of limestone applied, 

 and also to find the limestone still remaining in the soil, whether from appli- 

 cations made or from a supply native to the soil." 



Results of liming experiments by the Finland Moor Culture Society, A. 

 RiNDEi.L (Jalirb. MoarJx., 3-5 (1D1.',-191G), pi). /X-A^YT7).— A number of Uming 



