14 



MASS. EXPERIMENT STATION BULLETIN 195. 



nearly neutral for the best development of tobacco. This seems to be 

 particularly true where large quantities of lime have been applied to soils. 

 The "good" tobacco soils examined showed a comparatively high "lime 

 requirement," as determined by the Jones' method, using Haskins' factor 

 for Massachusetts soils (4.46 instead of 1.8). 



By the term "lime requirement," as used in this connection, is meant 

 the amount of lime in the form of calcium oxide, CaO, it would be necessary 

 to add to the soil to exactly neutralize it, i.e., make it neither acid nor 

 alkaline. It is not impUed that the amounts of lime indicated in any given 

 instance would benefit the tobacco crop. 



The writer believes that, as a measure of the actual "lime requirement" 

 or acidity of soils, none of the present methods of determination are satis- 

 factory, and do not, in many cases, even approximate the true value 

 sought; but when used as a comparative indicator for laboratory purposes 

 in the examination of a series of soils they may be applied with advantage. 

 In Table II will be found the "lime requirement" of some typical fields 

 examined, together with comments on the crop, type of soil, etc. 



Table II. — Classification of Certain Soils according to "Lime Require- 

 ment,^' together with Data on Crop Condition, etc.^ 



Group I. 



Group II. 



1 Tlie data given in this table represent only a part of the total collected, but are typical of 

 conditions in general. 



2 "No" indicates that no root-rot was found on roots of plants examined. It is entirely proba- 

 ble that a very extended examination might in all cases reveal a slight amount. 



