420 EXPEEIMENT STATION EECOKD. 



theoretical discussion of the importance of soil aeration for bacteria and plant 

 culture, by B. Heinze. 



It is stated that, after several years' observations, the conclusion was reached 

 that the most important factor concerned in the increased productivity of 

 a soil from tile draining is the improvement in aeration. In order, there- 

 fore, to bring about more perfect aeration he conceived the idea of connect- 

 ing the tiles with the atmosphere by means of flues or pipes, which consti- 

 tutes the method here described. It is maintained that such a system, which 

 entails very little additional expense beyond that of the original cost of tiling, 

 brings about a complete circulation of the air not only in the tiles but also in 

 the soil and, furthermore, that the temperature and humidity of the soil and 

 of the atmosphere tend to equalize as a result, thus having a most important 

 bearing on the productivity of the soil. 



Determinations were made from time to time of the organic matter content 

 and oxidizing power of soils aerated in this manner as compared with soils 

 not aerated. The results, although indicating greater bacterial activity in the 

 aerated soil, are as yet inconclusive. The experiments are being continued. 



On the penetration of soluble fertilizers into the soil, A. Demolon and G. 

 Brouet {Atin. /S'ci. Agron., 3. ser., 6 {Id 11), II, No. 6, irp. JfOl-418, figs. 2; abs. 

 in Internat. Inst. Agr. [Ro(me^, Bui. Bur. Agr. Intel, and Plant Diseases, S 

 (1912), Xo. J/, pp. 897-899). — The investigations reported in this article have 

 already been noted from a briefer report (E. S. R., 25, p. 120). 



The chemical composition of farmyard manure as a measure of its value, 

 C. Crowther and A. G. Ruston {Trans. Highland and Agr. Soc. Scotland, 5. ser., 

 2Jf {1912), pp. 219-236). — This article is based upon a study of the manure 

 obtained in 2 steer feeding experiments, the object of which was " to compare 

 a ration including a heavy allowance of roots and a moderate allowanee of con- 

 centrated foods with another ration including a moderate allowance of roots 

 and a high allowance of concentrated foods. The foods used were precisely the 

 same in each ration, the difference simply being in the relative proportions of 

 roots and concentrated foods." 



The composition of the difl'erent lots of manure produced and their effects 

 upon crops as tested in field trials are reported. It was found that " the differ- 

 ence in composition between the manures produced by animals fed under the 

 same conditions but on different rations may differ widely from that which the 

 composition of the foods consumed would lead one to expect. This is especially 

 the case where the amounts of ' roots ' included in the rations differ greatly. 

 The chemical composition of the manures by itself is not a reliable measure of 

 their relative values. . . . The richer manure in each case apparently [gave] the 

 better crop, but the differences in value thus far realized [were] well below 

 those calculated from the chemical composition by the ordinary method of 

 computation." 



The effect of watery foods (roots) in increasing the bulk and reducing the 

 fertilizing value of the manure was marl^ed. 



The manufacture of nitrates from the atmosphere. E. K. Scott {Jour. Roy. 

 Soc. Arts, 60 {1912), No. SlOJf, pp. 6^5-667, figs. 12; Nature [London], 89 

 (1912), Nos. 2227, pp. 1,63-1,65, figs. 3; 2228, pp. 1,90-1,92, figs, .i).— This is a very 

 complete account of the present status and outlook of this industry, describing 

 the various processes in use, the capacity of the works, the cost of power, and 

 the possible extension of the industry. 



The manufacture of nitrates from the atmosphere, H. E. P. Cottrell {Jour. 

 Roil. Soc. Arts. 60 {1912), No. 3108, pp. 756, 757).— This article contains sta- 

 tistics on the world's production and consumption of ammonium sulphate and 



