22 EXPERIMENT STATION RECORD. 



Nitragin and its value, A. Kuhn et al. (Mitt. u. PuJ). Bait. Hamenhau Ver- 

 bandes, 10 {190S), pp. J7W,6).— Beneficial results from the use of nitragin in a 

 large number of experiments with leguminous plants of different kinds are 

 reported. 



Concerning the existence of nounitrifying soils, F. L. Stevens and W. A. 

 Withers (Science, n. ser., 29 (1909), No. 743, PP. 506-508) .—Attention is called 

 to the fact that of 62 samples of normal agricultural soils tested at the North 

 Carolina College vStation, 44, or 71 per cent, failed to nitrify. 



The decomposition of nitrates by bacteria, S. A, Sevjskin (Centbl. Bakt. 

 [etc.], 2. Abt., 22 (1909), Xo. 11-13, pp. 348-310; abs. in Chcm. Ztg., 33 (1909), 

 No. 35, Repcrt., p. 167; Jour. Chem. Boc. [London^, 96 (1909), No. 557, II, pp. 

 255, 256).— This article reports further studies (E. S. R., 9, p. 1040) of the 

 denitrifying power of Bacillus pyocyaneus and Vibrio denitrificans isolated by 

 the author from manure. The studies were made with various culture media 

 and with soils of different kinds in presence and absence of oxygen. The 

 denitrifying power of both organisms was greater under anaerobic conditions 

 than in presence of air, the increase being greater in case of B. pyocyaneus 

 than in case of the other organism. 



The activity of the organisms in general corresponded to the fertility of the 

 soil, but in all cases B. pyocyaneus was more energetic than T. denitrificans. 

 The latter was less affected by additions of manure and straw than the former. 

 Manure favored denitrification more than straw. The exact rate of denitrifi- 

 cation was not determined, because the tests were qualitative in all cases and 

 in few cases was all the nitrate reduced. In no case was the presence of 

 nitrite observed. 



Soil fatigue caused by organic compounds, O. Schreineb and M. X. Sul- 

 livan (Jour. Biol. Chem., 6 (1909), No. 1, pp. 39-50. pi. /).— Previous investi- 

 gations bearing on this subject are briefly reviewed, and experiments with 

 wheat and cowpeas grown continuously on the same soil are reported. 



It was found that " as the number of recroppiugs increased tbe soil came to 

 such a condition that it would no longer give even a fair crop of [cowpeasj." 

 Since wheat and potatoes grew well on this soil after the failure of the cow- 

 peas and the water extract of the soil was found to contain large amounts of 

 plant food, it was concluded that the unproductiveness of the soil was due to 

 the presence of toxic matter. Experiments with water extracts of the soil gave 

 results tending to confirm this conclusion. By distilling the soil with steam,-a 

 distillate was obtained which yielded on standing crystals of an organic sub- 

 stance which was found to be toxic to cowpeas. The soil after distillation was 

 found to be more favorable to the growth of cowpeas than before. 



Barnyard manure: Its treatment and application to the soil, C. E. Thorne 

 (Penn. Dept. Ayr. Bui. 169, pp. 146-151). — This is a brief summary of the 

 results obtained in a long series of experiments at the Ohio Sation relating to 

 the losses which occur in manure which is improperly cared for and to the 

 need of reinforcing manure with other fertilizing materials, particularly phos- 

 phates. Fine-ground raw phosphate has been found to be a profitable material 

 to u.se for this purpose. 



Bat guano, R. F. Hare (New M-exico Sta. Rpt. 1908, pp. 35, 39). — Analyses 

 of a nunilxn- of samples of bat guanos are reported, and it is pointtxl out that 

 in view of the fact that these guanos contain nitrogen and phosithorus as well 

 as a certain amount of organic matter, they are an ideal fertilizer for New 

 Mexico soils. 



Green manuring, S. de Geazia (Ann. R. Staz. Cliim. Ayr. Sper. Roma. 2. ser., 

 2 (1907-8), pp. 33-46). — This article distinguishes between green manures 



