1116 EXPERIMENT STATION EECORD. 



power of the latter is but slij,'lill.v increased by symbiosis with Radiobacter. 

 Of the sugars tested as Sources of carbonaceous food of tlie organisms, 1-ara- 

 binose gave the best results, and rhamnt)se the poorest. With dextrose 99 to 

 224 gm. of sugar was converted into carbon dioxid for every gi-am of nitrogen 

 fixed. The results obtained with the various sugars suggest that the fui-- 

 fni'oids of the soil are the best source of food for Azotobacter. Nitrate of soda 

 inhibited nitrogen fixation, but apparently was not as good a food as free nitro- 

 gen. It was found that nitrite and anmionia were invariably formed when 

 nitrate of soda was used iif the culture medium, liadiobacter was shown to be 

 a powerful denitrifier, liberating free nitrogen from nitrate and exhibiting 

 intense respiration. 



Analysis of the bacterial mass produced in the cultures showed ash 8.6 per 

 cent, phosphoric acid 4.9 per cent, potash 2.4 per cent, and nitrogen 11.3 per 

 cent. 



Nitrogen and nitragin, A. J. Ewart {Jour. Dcpt. Agr. Victoria, 7 {1909), 

 No. 1, pp. 36-39). — This ai'ticle discusses briefly the nature and use of com- 

 mercial cultures of organisms which assimilate free nitrogen, and explains the 

 conditions under which such cultures are likely to be beneficial. The general 

 conclusion is that in the present state of linowledge of the subject the use of 

 these cultures is not to be recommended except under " very special conditions." 

 " The net result of the activity of soil bacteria in rich, well-manui'ed soils is to 

 produce a loss rather than a gain of nitrogen, and hence no advantage is to be 

 expected by the addition of cultures of any kind of bacterium to such soils." 



The inoculation of leguminous crops, F. J. Chittenden {Jour. Roy. Hart. 

 Soc. [London], 3-'f {190S), Xo. 2, pp. 231-25.), pi. 1, fig. 1; 3J, {1909), No. 3, pp. 

 491-Jf99). — In experiments at Wisley_ Garden in 1908 with peas treated with 

 the inoculating material prepared by Professor Bottomley of Kings College, it 

 was found in one series of experiments that " 7 out of the 12 plats on which 

 inoculated seed was sown gave smaller crops than the corresponding uninocu- 

 lated plats, and one gave an equal crop. . . .. The crop from the inoculated seed 

 was not better in any way than that from the uninoculated, nor did it reach 

 maturity earlier." In a second series of experiments " only 7 out of 24 I'ows 

 of inoculated seed gave a greater yield than the uninoculated, one gave an 

 equal yield, and 16 gave a smaller." 



Watering peas with the inoculating material gave like results. 



The general conclusion drawn is that the inoculation of leguminous crops 

 with the material used is not likely to prove beneficial in ordinary garden soils. 



Experiments on the value of nitro-bacterine, C. T. Gimingham {(Sard. 

 Chron., 3. scr., //.J {1909), No. 1152, pp. 59. 6'0).— Experiments with peas on very 

 poor and on well manured garden soil at the Southeastern Agricultural College, 

 Wye, are reported. "There was no evidence of any kind to show that the 

 slightest benefit had been obtained by the use of 'nitro-bacterine' on either 

 type of soil." 



Experiments on the value of nitro-bacterine, F. Keeble {Gard. Chron., 3. 

 ser., 1,5 {1909), Nos. 1150, pp. 20, 21; 1151, pp. 35, 36).— The results obtained by 

 Chittenden (noted above) are discussed, and experiments of a similar character 

 made on the grounds of the botanical laboratory of University College, Reading, 

 are reported. 



It was found in these experiments that the increase of yield from inoculated 

 seed was so small that it did not represent a sufficient increase of profit to make 

 the use of nitro-bacterine on ordinary garden soils of practical value. To this 

 extent the results confirm those reported by Chittenden, but they do not confirm 

 the conclusion that inoculation generally decreases the yield. 



