SOILS FERTILIZERS. 721 



0.5-normal solution but did adsorb water. The adsorption of iron by peat 

 moss was accompanied, by an evolution of hydrogen suggesting a possible 

 chemical reaction. Neutralizing the soil acids with calcium carbonate checked 

 the evolution of .hydrogen almost completely. There was no definite relation 

 between the extent of evolution of hydrogen and the adsoii^tion of iron from 

 ferric chlorid and colloidal ferric hydroxid. The colloidal character of the 

 peat moss had no effect on the evolution of hydrogen. 



The electrical conductivity was not a reliable indication of the absence of 

 humus acids in the soil. It was found that other organic acids which are 

 difficult to dissolve in water also showed a low electrical conductivity. Neutral 

 colloids like starch did not give the blue coloration of a mixture of potassium 

 salts of iodin, and starch paste. Only acids or acid containing substances, 

 such as Sphagnum acutifolium, Hylocoirvium schreberi, Cladonia rangiferina, 

 stems of TrifoUum liyhridum, stearic acids, humus acids, and peat moss, gave 

 this reaction. Leaching the adsorbed bases of plants which contain colloidal 

 substances did not affect the acidity. Peat moss inverted 96 per cent of 

 saccharose invertible by hydrochloric acid. 



The authors assert, on the basis of the foregoing investigations, that the 

 position taken by Baumann and Gully is untenable. 



Investigations on nitrogen transformation in different soils, H. Fisciieb 

 ET AL. {Landw. Jahrb., l/l {1911), No. 5, pp. 155-822). — The investigations here 

 reported consisted of a series of pot experiments with different soils to deter- 

 mine the rate of ammonification, nitrification, and denitrification in added 

 ammonium sulphate, dried blood, and sodium nitrate, using, respectively, 2.9537 

 gm., 4.65 gm., and 3.7S16 gm. per 2,837 gm. of soil with and without applica- 

 tions of lime, humus extract, and gi'ape sugar. The soils used were a loamy 

 sand and a light sand in one series of experiments, and a light loamy sand 

 which had been used in a 3-year fertilizer test with sodium nitrate and am- 

 monium sulphate. 



There was a larger and more rapid nitrification of ammonium sulphate in the 

 heavy soils than in the very light, sandy soils. Applications of lime increased 

 nitrification — the heavy applications (1 per cent) more so than the light ones 

 (0.3 per cent). The theoretical amount of lime (200 gm. of CaCOs) required 

 for the nitrification of ammonium sulphate (132.7 gm.) was not sufficient for 

 complete nitrification, but about three and one-half times the theoretical amount 

 was required. Ammonification of dried blood was more intense in light than in 

 heavy soils. Ammonification did not check nitrification in the least but rather 

 stimulated it in soils which nitrified ammonium sulphate only very slightly or 

 not at all. In the heavier soils there was besides nitrification a noteworthy 

 fixation of nitrogen ; this was not noted in light soils. The application of dried 

 blood stimulated nitrification irrespective of previous stimulation from appli- 

 cations of lime. There was a small but distinct variation in the bacterial 

 activity of the soils taken from the unfertilized, the ammonium sulphate, and 

 the sodium nitrate plats of the 3-year fertilizer test. Peat extract and grape 

 sugar stimulated nitrification. In light sandy soils receiving applications of 

 dried blood the loss of nitrogen by denitrification was greatest, being 7.29 per 

 cent for a period of 11 weeks. In the heavy, loamy sands there was very little 

 denitrification. The soils which nitrified poorly suffered the greatest loss of 

 nitrogen. There was no denitrification with medium applications of sodium 

 nitrate. Loss of nitrogen due to volatilization of ammonia occurred not only 

 with applications of quicklime but with the unbumed ground marl as well. 

 The lime in the soil seemed to have much less effect in this respect than even 

 very small amounts of added lime. Organic substances checked ammonilica- 



