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SOME RELATIONS OF ORGANIC MATTHR IN SOILS 
F. A. CarLson 
The effect of lime on the organic matter in soils has been 
for some time one of the leading problems for investigation. The 
results that have been recorded, however, are not consistent. 
Some investigators have reported that there is a greater accu- 
mulation of organic matter in limed than in unlimed soil, while 
others have stated the contrary: This difference of opinion is 
not surprising when the methods of experimentation, the soil 
variations, and the climatic conditions are considered. There 
has been, however, too great a tendency to draw conclusions 
from unreliable data. In many cases, attempts have been made 
to study the effect of lime on the organic matter in soils without 
a knowledge of the composition of the soils before treatment. 
In view of the many discrepancies in the reported results, 
the present experiment was designed to ascertain the effect of 
lime on the organic matter in soils under various treatments and 
cropping systems. 
HISTORICAL 
Wheeler and others (1899)! reported that lime decreased 
the percentage of humus in soils under continuous culture of 
cereals. They found also that there was an increase of roots 
and residual organic matter in limed grass plats as compared to 
those not limed. 
Hess (1901) studied the effect of lime on some of the Penn- 
sylvania soils. He stated that liming resulted in a SEEDPEER Or of 
the nitrogen. 
Kossovich and Tretjakov (1902) stated that the addition of 
calcium carbonate to soil retarded the decomposition of organic 
matter. ; 
Hartwell and Kellogg (1906) pointed ont that the amount of 
humus in limed plats was less than that in unlimed plats. They 
stated also that the effect produced by lime upon the organic 
matter of a given soil was dependable to a considerable extent 
on the degree of acidity or of alkalinity of the soil. 
1Dates in parenthesis refer to References Cited, page. 25. 
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