EXPERIMENT STATION BULLETINS. 



841 



CaO per acre. It appears that the peats, clay loams and silt loams take 

 up larger amounts of lime than the sands and sandy loams, although in 

 some cases the sands and sandy loams consume as much as the clay 

 loams, and silt loams. Soil No. 17, for instance, is a coarse sand, and 

 its lime requirement is the same as that of heavy silt loam No. 3, which 

 is 6,730.8 pounds CaO. Soils No. 20, 31, and 32 were obtained from the 

 Rhode Island Experiment Station through the kindness of Director Hart- 

 well. All these three soils were considered to be acid. Soil No. 22 re- 

 fused to produce satisfactory crops, according to Dr. Hartwell. This 

 soil may be classed as very fine sandy loam and yet its lime requirement 

 is very high. Soil No. 15 is a light silt loam and was kindly furnished by 

 Prof. A. J. Patten of this Station. It was considered to be very acid as 

 it turned the blue litmus paper red and showed a large lime requirement 

 by the Veitch method. Soils No. 24, 25, 26 and 27 are light silt loams 

 and were procured from the Pennsylvania Experiment Station plots 

 through the kindness of Prof. J. W. White. All these soils were supposed 

 to be acid. Soils No. 27, 29, and 30 are peats and show a tremendous 

 lime requirement. The amount shown above is based upon 1,000,000 

 pounds of soil ; if it were based upon 2,000.000 pounds as in the case of 

 the mineral soils, it would be twice as large. 



In order to see how the above lime requirements obtained by the freez- 

 ing point method, compared with those by the Veitch method, Prof. A. J. 

 Patten kindly determined the lime requirement of soils No. 3, 4, 15, and 

 16 by the latter method. These values are contained in Table 6. For 

 direct and convenient comparison the corresponding values indicated by 

 the freezing point method are repeated in this table. 



It is readily seen that the results yielded by the two methods do not 

 at all agree. The freezing point method indicates a far greater lime re- 

 quirement of every soil than the Veitch method. 



If to any one of the soils contained in Table 5 is added only half of the 

 amount of CaO indicated by the freezing point method, and the ratio of 

 soil to water is 1 to 5, the red litmus paper will immediately or shortly 

 turn blue. This, however, is found to be true even with the Veitch 

 method, and it is a pure case of hydrolysis, as already discussed. 



It will now be of interest to ascertain the type of curve that the various 

 soils in Table 5 yield. In Table 7 there are presented the numerical 

 data of a few examples which are typical of the various classes of soil. 

 These results are graphically represented in figures 6a, 6b, 6c and 6d. 



