222 EXPEEIMENT STATION EECORD. 



of soils, seasonal variations in nitrification, the relationship of crop production 

 to nitrifying energy in the soil, and the action of straw or other organic material 

 in the soil on bacterial action. 



A study on nitrogen transformation in soils, W. KBiJGER (Ein Beitrag zur 

 Untersuchung der Stickstofjumsetztmgen im Boden. Inaug. Diss., Konigsherg, 

 1908, pp. 58; rev. in Bot. Centbl., lUf (tVlO), No. 9, pp. 238, 239).— Experiments 

 were made on the influence of quicklime, calcium carbonate, and soil aeration 

 on nitrification, denitrification, nitrogen fixation, and the decomposition of 

 nitrogenous organic matter in humus, calcareous, and sandy soils, respectively. 

 The experiments were conducted with culture media, using the Buhlert and 

 Fickendey soil suspension method (E. S. R., 18, p. 120). 



It was found that the quicklime and calcium carbonate exerted a favorable 

 influence on all the bacteria concerned in the transformation of nitrogenous 

 compounds in the soil. The experiments show that each soil exerted a different 

 influence on the nitrogen transforming bacteria independent of the fertilizers 

 and aeration. 



In the fertilizer and aeration experiments, the sandy soils showed a smaller 

 nitrogen fixation and nitrification power than the calcareous and humus soils, 

 while the denitrification power seemed about equal in all the samples. 



In the experiments on the influence of different fertilizers on the power of 

 each soil to decompose nitrogenous organic matter, it was found that when 

 limed the humus soil stood first and sandy soil second in this respect. Marked 

 variations were obtained in the effects of the fertilizers on different soils, 

 caused apparently by changes in the physical and chemical composition 0!^:ii^tch 

 soil due to weather conditions. 



The author claims that by the method used no conclusion can be reached 

 concerning the condition of each soil, and that therefore only by actual tests 

 can it be determined whether liming and aeration will exert a favorable or an 

 unfavorable influence on the growth and multiplication of the bacteria. 



Legume inoculation and the litmus reaction of soils, K. F. Kellerman 

 and T. R. Robinson (U. *S'. Dcpt. Agr., Bur. Plant Indus. Circ. 11, pp. 11). — 

 This circular reports a continuation of investigations on soil conditions affect- 

 ing legume inoculation (E. S. R., 18, p. 533) and is based upon examinations 

 of " many difterent soils both in the field and by samples, with a view to cor- 

 relating, if possible, certain of their characteristics with their behavior toward 

 the growth of legumes and the nodule bacteria of legumes." 



The results are recorded of the relation between inoculation for alfalfa, 

 vetch, and crimson clover, and the litmus reaction of the different soils as 

 determined by the following method : " Strips of neutral litmus paper are 

 placed in the bottom of a number of petri dishes; over these are laid four 

 thicknesses of filter paper and on the filter paper are placed the soil samples 

 to be tested. Just enough water (tested and found neutral) is added to satu- 

 rate the soil on the filter paper. Covers are placed on the petri dishes, and 

 they are allowed to stand for one hour. A check petri dish containing only 

 litmus paper and filter paper moistened with the same water is allowed to 

 stand under the same conditions." 



The authors conclude from the results obtained that " the modified petri-dish 

 method, using neutral litmus paper, gives valuable comparative data for study- 

 ing legume inoculation. 



"Alfalfa inoculation is most inhibited by soils which redden litmus, and is 

 most successful in soils which blue litmus or in those which leave the litmus 

 paper unchanged. Crimson clover inoculation is limited little, if at all, by 

 soils of varying litmus reaction. Vetch inoculation seems midway between that 

 of alfalfa and that of crimson clover. A sharp distinction must be drawn be- 



