SOILS — FERTILIZERS. 7l3 



The temperature of soils and water near Breslau in comparison with the 

 temperature of the air, 15. Sciiitlzk niul H. MKiiuiNd ( l'ii}ilin!)'.s Lfiiitlir. Ztp., v57 

 ( liiOH), \o. 20, j). 6"7.?-()78, (Igms. S). — TLo results of observations tluring a series 

 of years (1!>01-100(!) (»ii the temperature of the soil at deptlis of from 20 to 

 130 cm., of tLie water of the Oder Kiver, aiul of the air are summarized and 

 eompared. 



The extremes of temperature at each depth were very nearly the same for the 

 () years, but decreased in different cases with the depth in the soil. The 

 greater the depth the greater the lag of the soil temperatures behind the air 

 temperatures. 



The average annual teni|)erature of the soil at a depth of 20 cm. was S.7° C, 

 corresponding very closely with that of the air (S.G°) and being about 1° lower 

 than tliat of tlie river water. The mean temperature at depths of 40, TO, 1(J<), 

 and 130 cm. was almost the same, I>.2 to 9.4°. 



The behavior of the organic matter of soils and the osmotic pressure of the 

 same, .7. KoNio, J. Hasenbaumer, and H. Grossmann (Landw. Vers. Stat., 69 

 (lOOS), \o. 1-2, ijp. 1-Dl, figs. 5; abs. in Chem. Zenthl., 1908, II, ^o. U,, pp. 

 1198, 1199; Chem. Zty., 32 {1908), No. 86, Repert., p. S^fS; Jour. Chem. 8oc. 

 [London], 9', (1908), No. 552, II, p. 888; Jour. Soc. Chem. Indus., 27 (1908), No. 

 23, pp. 1166, 1161; Chem. Abs., 3 (1909), No. 2, p. 221).— In continuation of 

 previous investigations, the authors studied 9 tyjiical soils with reference to 

 their chemical and jdiysical proi)erties and the behavior of the organic matter 

 of the soils under treatment with steam under pressure and when subjected to 

 oxidation by means of hydrogen peroxid. 



The methods and apparatus used in these treatments are described and data 

 are given for soil constituents dissolved by treatment with steam and with 

 hydrogen j)eroxid and for the carbon dioxid evolved in the treatment with the 

 latter substance. The laboratory experiments were supplemented by a series 

 of pot exi>erinients in whicli treated and untreated .soils were used for the 

 growth of barley and oats witli and without the addition of fertilizer mixtui'es 

 of difl'erent kinds. The methods used and the results obtained in a series of 

 studies of the osmotic pressure of the soil and of various salts, carbohydrates, 

 etc., are given in detail. The results of the investigations were in brief as 

 follows: 



(1) By treatment of soil with steam under pressure the plant food present 

 in the form of comi)lex salts or inorganic matter is brought into solution. While 

 the pH'ssnre to be used will depend ui)on the kind of soil, ,"> hours' treatment 

 with steam under a i)ressure of ."> atmospheres (;"> liters of water to 500 gni. of 

 s<jil) was iisuMlly found to be the most effective treatment. 



(2) This treatment is capable of showing the larger dift'ereiUH's in a content 

 of more easily s<»luble nutrients, but is not capable of showing the small dif- 

 ferences due to the use of fertilizers. 



(3) Treatment with hydrogen peroxid renders soluble like but somewhat 

 higher (piantities of these |tlant food c(»nstitnents, but this method is not 

 capable of indicating slight differences in soluble constituents, as for example, 

 th<»se due to application of fertilizers. 



(4) .\ small projtortion of the soil constituents not dissolved out of soils by 

 pure water or by water containing carbon dioxid becomes soluble in water 

 under treatment with steam under jiressnre in the presence of humus acids or 

 by oxidation. This Is thought to Indicate that part of the constituents are 

 present in comi)lex (tr organic combination, as has been found to be the case 

 In moor soils. These constituents, which perhai»s are In combination with 

 himnis acids, are doubtless Imiiorlaut sources of nilneial nutrients <»f plants. 



