Scientific Agriculture, 



330 



[October, 1909. 



indeed, little superiority in its influence 

 upon the crop yield to that shown by 

 the original nifcragin preparation of 

 Nobbe and Hiltner, Although in a very 

 considerable number of cases, small in- 

 creases of crop followed inoculation, yet 

 the general verdict from the American 

 experiment stations, and also from 

 European stations where Moore's cul- 

 tures had been tried, was that these 

 preparations were inefficient. The 

 advantages of inoculation by means of 

 pure cultures were obvious in theory, 

 but the ideal pure culture, the use of 

 which would cause these advantages to 

 appear in practice, had yet to be 

 devised. 



Investigation carried out with the 

 object of ascertaining the cause of these 

 disappointing results showed that the 

 method of preserving the bacteria in a 

 dried form on cotton was not so satis- 

 factory as had been supposed. Many of 

 the organisms perish during the process 

 of drying, and any considerable change 

 in temperature and moisture conditions 

 that may take place previous to the 

 use of the culture has a detrimental 

 effect upon the vitality of the bacteria 

 that still remain. By Moore's method, 

 too, the actual preparation of the culture 

 solutions with which the legume seed 

 was to be treated before sowing, had to 

 be carried out by the farmers them- 

 selves, who would hardly be likely to 

 work ucder the careful and exact con- 

 ditions that would be followed in 

 the laboratory. Under ordinary farm 

 circumstances, the risk of contamination 

 by the introduction of foreign bacteria, 

 moulds, and yeasts, from the air, from 

 water, or by means of the utensils em- 

 ployed, was at its maximum, and many 

 of the introduced organisms might be 

 instrumental in preventing the growth 

 and multiplication of the nitrogen- 

 gathering bacteria of the cotton culture. 



Culture preparations for inoculation 

 of leguminous crops are still sent out by 

 the United States Department of Agri- 

 culture, but as a result of the difficulties 

 that have been experienced, the use of 

 absorbent cotton has been abandoned, 

 and the medium employed, consists of 

 nitrogen-free liquid put up in her- 

 metically sealed bottles. Numbers of 

 different cultures are prepared, which 

 correspond to the different legume crops 

 cultivated, each culture being adapted 

 to give the best results with a particular 

 species. Thus cowpea cultures, alfalfa 

 cultures, clover cultures, etc., are all 

 obtainable. The directions that accom- 

 pany each bottle warn the recipient to 

 utilize the material within ten days or 

 two weeks, as otherwise deterioration 

 may set in, which will render the culture 

 useless. 



Nearly two years ago Professor 

 Bottomley, F.R.S., of London, turned 

 his attention to the subject of soil 

 inoculation, and as the outcome of his 

 investigations, he brought forward 

 another pure culture preparation, some- 

 what similar to that of Moore, to which 

 the name ' Nitro-bacterine ' was given. 

 'Nitro-bacterine' was described by the 

 originator as a ' powder preparation of 

 the bacteria.' It was sent out in sealed 

 packets containing cotton wool, as in 

 the early American method, but the 

 medium also contained in addition a 

 number of dry, earth-like particles. 

 With these packets were sent also small 

 quantities of soluble nutritive sub- 

 stances, to be dissolved in water, and 

 che culture solution was prepared and 

 utilized in a manner similar to that 

 already described in the case of Mcore's 

 cotton cultures. The importance of 

 using pure water that had been boiled 

 and allowed to cool, perfectly clean 

 utensils, and of taking every precaution 

 to protect the solution from contamina- 

 tion was emphasized by Professor 

 Bottomley. Those testing nitro-bacterine 

 were advised that inoculation might 

 also be effected by 'watering' the young 

 legume plants with the culture solution. 

 It may be added that Professor Bottomley 

 did not confiue his attention to legum- 

 inous plants alone in this connexion. He 

 also brought forward other culture pre- 

 parations which he hoped might be 

 instrumental in enabling cultivated 

 plants belonging to certain other natural 

 orders to draw upon the stores of 

 atmospheric nitrogen for food purposes. 



The results so far reported with nitro- 

 bacterine have not been of such a nature 

 as to indicate that this preparation is 

 in any way superior as an inoculating 

 material to Nobbe and Hiltner's nitragin 

 or. Moore's cotton cultures. In the 

 summer of 1908, some experiments with 

 Professor Bottomley's culture material 

 were conducted with garden peas at the 

 Wisley Gardens of the Royal Horticul- 

 tural Society. These are reported upon 

 in detail in the Journal of the Society 

 for November last (Vol. XXXIV., part 2), 

 and a summary of the results was given 

 in a late number of the Agricultural 

 News (Vol. VIII., p. 02). These results 

 were of a purely negative character, and 

 the closing paragraph of the report is 

 as follows : ' It is concluded that the 

 inoculation of leguminous crops with 



nitro-bacterine 'in ordinal y garden 

 soils is not likely to prove beneficial.' 



During the year 1908, the effect of 

 inoculation on the returns given by 

 various leguminous crops was tried at 

 Antigua and at Grenada. In the former 

 island where cowpeas, woolly pyrol, and 



