522 EXPERIMENT STATION RECOED. 



The potassium and phosphoric acid of the dipotassium phosphate, given in 

 quantities below the maximum absorptive capacity, were absorbed completely, 

 while the sulphuric acid of the sulphates was absorbed only partly, and the 

 chlorin of the chlorids and nitric acid of the nitrates remained unabsorbed. 

 The absorbed nutrients did not again go into solution upon treatment of the 

 soil with water. The soil treated with potassium phosphate showed no in- 

 crease in electrolytic conductivity; on the other hand, those treated with 

 chlorids, nitrates, and sulphates did show an increase, a fact indicating that 

 both the potassium and phosphoric acid of the potassium phosphate are ab- 

 sorbed. 



Soils treated with hydrogen peroxid showed an increase in yield of vegeta- 

 tion provided the soils were supplied with a complex humus acid salt or 

 humus colloids. A definite action similar to that of the hydrogen peroxid was 

 not obtained with calcium peroxid. Plants grown on a soil poor in potassium 

 and rich in lime assimilated a small amount of the former and a correspond- 

 ingly larger amount of the latter and vice versa. It appears that these two 

 bases have the property of replacing each other in the soil to a certain extent. 

 The growth of red clover increased the soluble nutrients of the soil as was 

 shown by the increased yield of rye, the increased amount of material rendered 

 soluble by steaming, and the improved osmotic properties of the soil follow- 

 ing the growth of clover. 



The determination of the electrolytic conductivity of soils, J. Konig, 

 J. Hasenbaumer, and H. Metering {ZtscJir. Angeiv. Chem., 2Jf (1911), ZVo. 3, pp. 

 103-106, figs. 3). — This is a brief account of investigations reported in full in 

 the article noted above. 



The amount of water in certain soils at the end of the winter of 1909-10, 

 A. Demolon and G. Brouet {Jour. Agr. Prat., n. ser., 19 {1910), No. 11, pp. 

 535, 536). — With a view to determining the variation in degree of saturation 

 of diffei'ent kinds of soils, determinations were made of the moisture in sandy, 

 clay, and humus soils after a prolonged wet period. It was found that the 

 humus and clay soils were nearly saturated while the sandy soil contained 

 only half as much moisture. 



Relations between physical constitution of soils and the distribution of 

 irrigation waters, A. MtJNTz, L. Faure, and E. Laine {Ann. Dir. Hydraul. et 

 Amelior. Agr., Min. Agr. [France], 1907, No. 36, pp. 121-223, pis. 6, figs. 12).— 

 In continuation of previous studies on the relation of permeability of the soil 

 to irrigation (E. S. R.. IS, p. 288)", the authors extended their investigations 

 to include the relation of other physical properties, including mechanical com- 

 position, absorptive power, density, porosity, capacity for water and air, and 

 capillarity, in addition to permeability. Special forms of apparatus for study- 

 ing the physical properties of the soil in place and in the laboratory are 

 described, and the investigations were made upon a large number of different 

 kinds of soil. 



The results confirm those of previous investigations in showing that per- 

 meability is the controlling factor in relation to the water requirements of 

 soils, and that by careful determinations of this property it is possible to esti- 

 mate with a high degree of accuracy the method and rate of irrigation which 

 will give the best results on any given soil. 



A simple form of apparatus for determining permeability of soils in place 

 is shown in figure 1. It consists essentially of a steel eyluider C 25 em. long 

 and 112 mm. interior diameter, which is carefullv forced into the soil to the 



<^ See also Ann. Dir. HydrauL et Amelior. Agr., Min. Agr. [France], 1905, No. 

 33, pp. 45-96, figs. 3. 



