514 EXPERIMENT STATION RECORD. [Vol.36 



The gain in nitrogen from the growth of legumes on acid soils, E. B. Feed 



and B. J. Graul {Wisconsin Sfa. Research Btil. 39 {1916), pp. 42, figs. 20). 



This is a progi-ess vt-port of pot and field experiments made to study the growth 

 and nitrogen-fixing power of red clover, alfalfa, and soy beans in acid Colby 

 silt loam and acid Pluinfield sand under the influence of liming and inoculation 

 and to study the nitrogen balance in an acid soil before and after growing a 

 leguminous crop. 



It was found that inoculation and liming produced striking increases in plant 

 growth, half enough lime to neutralize the soil acidity being sufficient for the 

 production of good crops. " The growth and nitrogen content of alfalfa plants 

 on Colby silt loam soil are greatly increased by inoculation. This influence was 

 most noticeable in the limed series. The benefit of lime alone was much less 

 pronounced than inoculation alone. In the case of soy beans in the same soil, 

 inoculation caused a very marked increase in both yield and quantity of 

 nitrogen. Lime apparently did not have any decided influence on soy beans." 

 In the Plainfield sand an enormous increase of nitrogen in the plant was noted 

 from inoculation, especially after the .second cutting. 



Clover on Colby silt loam responded only slightly to liming and not at all to 

 inoculation, but on Plainfield sand responded readily to both inoculation and 

 liming. The results obtained from field experiments with alfalfa and soy 

 beans on Colby silt loam agreed in general with those of the pot tests. 



Two fundamental facts are brought out, (1) that the characteristic effect of 

 inoculation of alfalfa on acid Colby silt loam and acid Plainfield sand is an 

 increase in plant growth and in the fixation of atmospheric nitrogen, and (2) 

 that small applications of lime on acid soils are more economical than large 

 applications. 

 Twenty-one references to literature bearing on the subject are appended. 

 The physiologically acid and alkaline salts and their importance in the 

 explanation of soil sickness, J. H. Aberson {Meded. Rijks Hoogere Land, Tuin 

 en. Boschbouwsch. [Wageningen], 11 {1916), No. 1-3, pp. t-128, pis. 10).— The 

 work of others bearing on the subject is reviewed, and experiments are reported 

 from which the following conclusions are drawn : 



The physiologically acid and alkaline salts exert very little influence on soil 

 reaction in the field, although much of the lime is lost from soil by heavy 

 fertilization with ammonium salts, thus causing marked changes in the soil 

 properties. Changes of soil reaction in pot cultures can be considered as repre- 

 senting field conditions in only a very general way. The alkaline or acid 

 reaction of the soil is not the cause of the so-called dry spot sickness (Diirr- 

 fleckenheit). 



It is stated that the dry spot sickness appears on all soils, but when am- 

 monium sulphate is used the disease has a different appearance than the 

 so-called acid sickness attributed to the slow formation of nitrites. The disease 

 was found to accompany the occurrence of nitrites in soils and Bacillus nitrosus 

 was obtained in pure culture. Injurious action took place only where nitrifica- 

 tion was slow and insufficient, and treatment producing active nitrification 

 eradicated the trouble. 



The vertical distribution of phosphorus in the surface soil of prairies, 

 F. J. Alway and C. O. Rost {Soil ScL, 2 {1916), No. 5, pp. .^93-^97).— Deter- 

 minations of the phosphorus content of each inch section of the surface foot of 

 the soils of 30 virgin fields in six different areas of the Nebraska loess, made 

 at the Minnesota Experiment Station, are reported. 



It was found that "prairie loess soils in the surface foot show a steady de- 

 crease in phosphorus from the surface inch downward, independent of the 



