10 LEGUME INOCULATION AND THE LITMUS REACTION OF SOILS. 



Table IV.— Relation between the litmus reaction of soil and the inoculation of crimson 

 clover with jpure cultures of nodule bacteria — Continued. 



LITMUS UNCHANGED. 



Locality. 



Jamesville, N. C. 

 Ashboro, N. C. . . 

 Kichfield, N. C. 



Convent, La 



Avden, N. C 



Ore Bank, Va.... 



Jefferson, Va 



Perkasie, Pa 



Bussellville, Ala. 



Kind of soil. 



Mississippi flood plain . 



Piedmont... 

 Central clay. 

 Dekalb...;. 

 Hagerstown. 



Result of 

 inocula- 

 tion. 



+ 

 + 



+ 

 + 

 + 

 

 



LITMUS REACTION BLUE. 



Hover, Wash. 

 Siloam, Ga. .. 



Seniiarid. . 

 Piedmont. 



DISTRIBUTION OF SOILS SUBMITTED TO THE LITMUS TEST. 



While the Utmiis test is suggested merely as an empirical one in 

 connection with legume culture, especially in the selection or treat- 

 ment of fields for the successful growing of alfalfa and clovers, it is of 

 interest to note the relation between the reactions obtained by this 

 method and the range of annual precipitation represented by the soils 

 tested. As shown in Table V, the soils w ere grouped as from (1 ) semi- 

 arid regions or regions of deficient rainfall; (2) regions of moderate 

 rainfall; and (3) humid regions. The figures represent the number 

 of samples in each group reacting as red or blue to htmus, or wliich 

 produce no change. 



Table Y.— Reaction of soils to litmus, the soils being grouped according to regions 



receiving different quantities of rainfall. 



Of the 4 semiarid soils showing red reaction to litmus, 3 came from 

 a region liaving an 18-inch rainfall; of the 28 humid soils showing 

 blue reaction to litmus, 17 whereof the Hagerstown series, formed from 

 pure massive limestone aiid therefore often having sufficient lime in 

 them to withstand cultivation and the leaching effect of heavy rainfall. 



[Cir. 71] 



