422 EXPEEIMENT STATION EECOED. 



on two experimental farms are reported. The results were not conclusive, but 

 indicate " no very great ad^'antage from the use of the subsurface packer." 



The contest for water between soil and seed, A. Muntz {Compt. Rend. 

 Acad. Sci. [Paris], 151 (1910), ^''o. 19, pp. 7.90-793).— Experiments with wheat 

 in soils of different kinds under varying conditions of moisture are reported, 

 showing that the seed and the soil struggle for the possession of the water 

 until an equilibrium is reached which depends upon the specific afflnities of the 

 two for water, and that not until this affinity is satisfied in case of the soil can 

 the grain germinate. These results confirm the author's broad conclusion that 

 vital processes in general are to a large extent a continuous struggle for water 

 between the lining organism and the medium in which it grows. 



The nitrogen and humus problem in dry-land farming, R. Stewaet 

 {Utah »S7(/. Bid. 109, pp. 3-J6).— This bulletin reports results of studies of the 

 humus and nitrogen content of virgin soils and contiguous soils which have been 

 dry farmed (by continuous croiiping or with summer fallowing) for different 

 lengths of time in the Cache Valley. The conclusions reached were as follows : 



" The cropping of dry-farming land in Cache Valley to wheat, either by the 

 summer fallowing method or by continuous cropping, does not decrease the 

 nitrogen or humus of the surface foot of soil. 



" The second foot of grain-cropped land contains less nitrogen and humus than 

 does the second foot of the adjacent virgin soil. 



" The cropping of dry-farming land to alfalfa causes a decrease of the nitrogen 

 and humus over that of the adjacent virgin soil. 



" The observed phenomenon in case of the grain-cropped land is probably 

 due to the addition of nitrogen to the surface foot from lower depth and the 

 addition of the humus from the added straw. 



" The work of this bulletin indicates that in a study of the nitrogen problem 

 in dry farming attention must be paid to greater depth of soil than the tra- 

 ditional plowed surface." 



The nitrogen and humus problem in dry-land farming, R. Stewart 

 {Jour. Indus and Engin. Cheni., 2 {1910), No. 9, pp. 386-388). — ^A brief account 

 of the above investigations. 



The humus acids of peat moss, W. Bersch (ZtscJir. MoorkuUur u. Torfver- 

 wert., 8 (1910). Xo. J/, pp. 20/f~2H). — This article is based upon investigations 

 by Baumann and Gully which have already been noted (E. S. R., 23, p. 715). 



The mineralogical significance of pot experiments, J. Samojlow {Centhl. 

 Min.^ Geol. u. Paldontol., 1910, No. 9, pp. 251-262, figs. 2; ahs. in Chem. Zentbl., 

 1910, I, No. 26, pp. 2132, 2133).— The object of the study here reported was to 

 show how pot experiments may be used to determine the chemical constitu- 

 tion of the minerals which furnish plant food in the soil. 



In culture experiments with Aspergillus niger potash was supplied in the 

 form of finely powdered orthoclase, niicrocliue, muscovite, and biotite. The 

 potash of all of these minerals was assimilated to some extent, but much better 

 growth was obtained wath muscovite and biotite than with orthoclase and 

 microcline. 



The various minerals were tested as sources of potash in pot experiments 

 with wheat, buckwheat, and vetch. In a comparison of the easily weathered 

 orthoclase with the more resistant microcline better yields were often obtained 

 with the latter than with the former, and in no case was the yield with the 

 microcline less than that with the orthoclase. 



Vetch made better growth on sanidine than on orthoclase but very poor 

 growth on leucite. The potash resulting from the weathering of microcline 

 circulated more readily in the soil than that of orthoclase. The potash of 



