100 



it seems to classify a soil more accurately than any other single factor in- 

 vestigated. It will be noted from all tables that the nitrogen, phosphorus, 

 acid soluble matter and crop yield increase as the per cent of organic 

 matter increases. 



Tlie plant food solultle in dilute acid (n/f)) is l.DS per cent for soils in 

 table 1 having a volatile content of 2 to 3% whereas that for table 7 con- 

 taining 10% or over averages 7.88% soluble in this acid, besides the latter 

 shows a high corn yield comj tared with that shown in tables 1 and 2. 



It will lie noted that nearly all soils produced some carbon dioxide gas 

 (4 to G c. c. ) when treated with hydrochloric acid including those slightly 

 acid to litmus. This indicates that a small evolution of gas when treated 

 with acid does not prove the soil is not acid as is often noted in the liter- 

 ature. 



It will be noted also from tallies 1, 2 and 3 containing low organic matter 

 that the soils most acid to litmus belong in these three groups and embrace 

 about 70 i^er cent of the total. In comparing the nitrogen content of the 

 different groups of soils noted in tables 1 to 7 with that of counties previ- 

 ously reported in the Proceedings it is found that the claij soils with a 

 volatile content of to 4% contain the following amounts of nitrogen in 

 lbs. per acre for the different counties. Elkhart County 2,049, Allen County 

 3.667, Hancock County 2,779, and Cass County 1,743. 



Where the clay loams predominate with a volatile content of 4 to 6% 

 Elkhart County contained 2,553 lbs. of nitrogen per acre, Allen County 3,985 

 lbs.. Hancock County 3.372 and Cass County 2,700. 



The. loam soils with a volatile content varying from 6 to 10% were higher 

 still — Elkhart County soils contained 4,213 lbs. per acre, Allen County 5,305, 

 Hancock 5.259, and Cass County 4,411. The above figures were obtained 

 from the analyses of over 400 samples of soils representing all townships 

 in each of the counties. 



