134 ALFALFA FARMING IN AMERICA. 
and soil subjects. No pretensions are made to special qualifica- 
tions in this line, but none the less the writer is firmly convinced 
that more than soil chemistry, as it has been applied for a 
century, and more than soil physics, as so ably enlarged within 
two decades, is needed to furnish the explanation of the vital 
changes of the soil and their relation to successful agriculture. 
When the line between calcareous or limestone outcrop and 
sandstone outcrop marks as it does the line between profitable 
land and unprofitable land for certain crop purposes, as it seems 
to do in some portions of Ohio, it may not be wholly heretical to 
look to the calcareous compounds as offering at least a part of 
the explanation of the differences. When history adds the weight 
of evidence in the maintained fertility of particular calcareous 
soils the same question is again raised. And since the soil chem- 
ist and soil physicist have not marked out the differences either 
in kind or degree, an appeal to the soil biologist, to the soil 
bacteriologist should now be made. Chester of the Delaware sec- 
tion once made determinations of the number of bacteria in a 
gram of a certain Delaware soil before and at periods of a 
few weeks after this soil had been treated to dressings of lime 
of various amounts and to Thomas slag. These were all 
in pots in comparison with untreated soil from the same source. 
The acidity of the original soil was determined and the amount 
of correction afforded by the treatment was also determined by 
the same method; while the untreated soil maintained an almost 
uniform bacterial floral of about 520,000 bacteria per gram of 
soil, the soil treated to dressings of lime showeu only a partial 
correction of apparent acidity, but an enormous increase in the 
number of bacteria per gram of soil. With smaller amounts of 
lime, say at the rate of 1,000 pounds per acre, the number of 
pacteria reached 2 to 3,000,000 per gram while with 4,000 pounds 
of lime dressing per acre, the number of bacteria reach 5 to 
8,000,000 per gram of soil. If nothing more may be said, we cer- 
tainly conclude that these results are very suggestive. I wonder 
if we have really begun the study of the problem of applying | 
lime to siliceous soils? 
Basic Slag a Source of Lime—There is a phos- 
phatic fertilizer on the market in eastern states 
wherever convenient to ocean ports that combines 
very nicely available phosphorus and lime. That is 
the Thomas phosphate or basic slag meal. This 
stuff is a by-product of the steel mills of England 
