1050 EXPERIMENT STATION RECORD. 



The conclusion is reached "(1) that few noils throughout middle Georgia are likely 

 to be found not already thoroughly colonized or inoculated with the special form of 

 PSeudomonas radicicola which uses the cowpea as its host. (2) Consequently, whether 

 the commercially distributed 'cotton-dried' nitro-culture for the cowpea does or 

 does not contain living colonies of this bacterium, it is valueless here." 



( >1 nervations on a series of introduced leguminous plants indicate that the cowpea 

 organism, which is everywhere abundant in the soils of the station farm, is capable 

 of inoculating leguminous plants of widely differing species. Among the unusual 

 plants so tested and found to develop root tubercles when grown for the first time 

 on the station farm were green gram (Phaseolus riridissimus), Newman bean (P. 

 mungo), P. radiatus, P. aconitifolius, and P. angustissimus. 



"Now, the bacteria forming these tubercles were derived either from the soil itself 

 (that is, from the universally disseminated cowpea bacteria) or were conveyed by the 

 planted seed. The latter hypothesis, though possible, is unlikely, especially since 

 desiccation has been proven so extremely fatal to P. radicicola. Had the seed been 

 sterilized before planting it would have, of course, 'determined the matter; but the 

 plat was merely a variety test of certain Phaseoli, with no reference to its bearing 

 upon soil inoculation. In either case it seems to indicate that our soil is not depend- 

 ent upon artificial inoculation." 



Soil inoculation for legumes from artificial cultures by the help of bac- 

 teria, C. I). Woods and J. M. Bartlett (Maine Sta. Bid. 126, pp. 28-30).— Negative 

 results in inoculation experiments with peas, clover, and alfalfa on a number of farms 

 in different parts of Maine during the season of 1905 are reported. The cultures 

 used for inoculation were' obtained from this Department and from a commercial 

 concern. The farmers of the State are cautioned not to depend upon such cultures, 

 but in case of attempts to raise leguminous crops not commonly grown in the region 

 to inoculate their land with soil from fields on which the crops have been grown. 



An experiment with Moore's cultures of nitrogen-fixing- bacteria, V. Peg- 

 lion (Staz. Sper. Ayr. Ital., 38 {1905), No. 9, pp. 769-784, ph. 4).— The results of 

 experiments with medic, lupines, sulla, and white clover on virgin and cultivated 

 soils indicate as a rule that Moore's cultures were very active in producing root 

 tubercles and in increasing growth in soils which had not already been inoculated 

 by natural means; but the writer points out that such conditions are exceptional in 

 localities where legumes of various kinds have been grown for centuries, and hence 

 the cultures have only a limited usefulness in practice and should not be expected 

 to take the place to any extent of good cultivation and the application of mineral 

 fertilizers to promote the growth of legumes. 



Nitrification of the organic matter applied to the soil in form of sewage, 

 G. Masoni (Atti R. Accad. Econ. Agr. Georg. Firenze, 5. ser., 2 (1905), No. 3, ]>)>. 

 196-208). — This is an account of a continuation of previous experiments by the 

 author and relates particularly to the relation of moisture to denitrification. 



The experiments here briefly reported lead to the conclusion that liquid sewage 

 from cesspools is not only capable of rapidly nitrifying when applied to the soil, but 

 also aids nitrification in the soil itself. Loss of nitrogen from the soil during hot 

 dry summer weather may be checked by applications of sewage. 



Recent experiments in the nitrogen-enrichment of soils, F. T. Shutt and 

 A. T. Charron (Separate from Proc. and Trans. Roy. Soc. Canada, 2. ser., 11 (1905), Sec. 

 Ill, pp. 53-64) . — This paper (1) presents the results of certain recent researches that 

 demonstrate the extent and rapidity of the depletion of soil nitrogen under what is 

 evidently an irrational method of farming, and (2) brings forward data to show the 

 value of the legumes, especially clover, as a means of maintaining and increasing fer- 

 tility through the addition of nitrogen and humus. The discussion is based upon 

 field and laboratory studies made by the authors at the Canadian Experimental 

 Farms. 



