1018 EXPERIMENT STATION RECORD. 



suiti)lonu'iiteil by coiuuiercial fertilizers, and '" that the best results can be ob- 

 tained only by a continuous and systematic use of fertilizers in connection with 

 M well ordered method of oroi)i>inj;." 



Theories of manure and fertilizer action, A. D. Hall {Science, n. ser., 

 ^8 (J'.)OS), No. Il23, pi>. 6n-i)28, fiy. I; Amcr. Fcrt., 30 {J<>Oi)), Xo. 3, pp. 

 23-30). — This is a lecture jrlven at the Graduate School of Afiriculture at Cor- 

 nell I'niversity in July, 19()S, and discusses at some lenj,'th the various theories 

 which have been advanced to explain the action of manures and fertilizers, the 

 discussion being based mainly upou Liebig's geueralizatious and conclusions 

 from the results of experiments at Rothamsted and of iuvestigatious of the 

 Bureau of Soils of this Department. 



The author concludes that there is no direct proof of the supposition "that 

 all soils give rise to soil solutions sufficieutly rich iu the elements of plant food 

 to nourish a full crop did not some other factor come into play," nor convincing 

 evidence "of the excretion of toxic substances from plants past the autotn^phic 

 seedling stage. . . . 



" If, however, we give the theory a wider form, and, instead of excretions 

 from the plant, understand debris of any kind left behind by the plant and the 

 results of the bacterial action upon it, we may thereby obtain a clue to certain 

 phenomena at present imperfectly understood. ... 



"Assuming that the persistence in the soil of obscure diseases ai^propriate 

 to the i)articular plant can be neglected as the cause of these phenomena, there 

 still remains some unexplained factor arising from a plant's growth which is 

 injurious to a succeeding crop, and this may either be the excreted toxins of 

 Whitney's theory or may be some secondary effects due to the competition of 

 injurious products of the bacteria and other microUora accumulating iu the 

 l)articular soil layer in which the roots of the crop chiefly reside." 



[Miscellaneous fertilizer notes] {Sugar Beet, 30 {1909), Xo. 1, pp. 18-21). — 

 Brief notes are given on European investigations on the acclimatization of 

 nitrifying organisms, the use of manganese as a fertilizer, the jihysiological 

 function of potash in plants, the importance of soda in the growth of sugar 

 beets. Thomas slag as a fertilizer for sugar beets, and toxic substances iu soils. 

 The investigations on which these notes are based have already been noted. 



Experiments with chemical fertilizers in 1908, E. Ciiuaru and C. Dusserkf 

 {Bui. Hoc. Yuud. A(jr. ct Vit., 1909. Xo. 2.25, pp. Jfl3-,W8).— Cooperative experi- 

 ments with 10 farmers in 5 different localities in the Canton of A'aud to deter- 

 mine the profitableness of applying sui)erphosphate, nitrate of soda, and potash 

 salts on well manured soils of good productive capacity are reported. The 

 results show that the chemical fertilizers gave profitable returns on wheat, oats, 

 and maslin (mixed grain). 



Cooperative fertilized experiments in Sweden, 1907, P. Bolin {K. Landthr. 

 Akiul. 11(1 inH. 0(7/ Tid.shr., J,7 (1908), Xo. J,, pp. 177-265, dgni.'i. 5). — The experi- 

 ments, similar in plan to those of previous years, were conducted with spring 

 grains, root crojis. meadows, and lupines. "Comparative trials with nitrate of 

 soda and calcium cyanamid, and variety tests were also conducted. 



Results obtained with different forms of nitrogen, Clausen (Landw. 

 M'clnibl. SchUs. Hoist., 59 {1909). Xo. /,, pp. 47-50).— Comparative tests of 

 nitrate of soda, lime nitrogen. Norwegian nitrate, and ammonium salts with 

 rye. barley, oats, and potatoes are reported. 



The Norwegian nitrate was fully as eft'ective as the better known nitrate of 

 soda and sulphate of ammonia. The lime nitrogen was especially effective on 

 potatoes and rye, but less so on summer grain. The high absorptive power of 

 the Norwegian nitrate for moisture and the very finely powdered condition of 

 the lime nitrogen interfere somewhat with their handling. 



