SOME RELATIONS OF ORGANIC MATTER IN SOILS iLTL 
When corn was growing on the plats in rotation, the unplanted 
plats were hoed at the same time and in the same way as were 
the plats planted to corn; when other crops were growing on 
the planted plats, the unplanted plats were merely scraped with 
a hoe. 
The mixtures of grasses used consisted of timothy, Kentucky 
blue grass. and redtop. 
Results 
Organic carbon and total mtrogen in plats before and after treat- 
ment 
The results recorded in tables 2 and 8 represent the aver- 
ages of duplicate determinations. The percentages of carbon and 
nitrogen before and after treatment are given, as well as the 
differences and the percentage of increase or decrease for the ten- 
years period. The total amounts of carbon and nitrogen added 
to the plats in manure, have been subtracted from the amounts 
of carbon and nitrogen determined on analysis after treatment. 
The data show that in the first foot, in every case but one, 
the limed plats contained more organic carbon than did the 
unlimed plats. This is very significant in the plats kept in 
grass. Plat 7012, kept in grass and limed, shows an increase of 
20.5 per cent of organic carbon in comparison to an increase of 
14.5 per cent in plat 7006, which had the same treatment and 
cropping except that it was not limed. Plat 7002, cropped in 
rotation but not limed, shows a decrease of 24.5 per cent of or- 
ganic carbon in comparison to a loss of 3.1 per cent in plat 7008, 
which had received lime. This difference is not attributed en- 
tirely to the lime. Plat 7002 was exposed to greater erosion and 
more complete drainage than was plat 7008. All plats in rota- 
tion show a decrease in organic carbon in the first foot, while 
there is a marked gain in organic carbon in the first foot in 
the plats kept permanently in grass. 
The use of legumes in rotation did not materially affect the 
organic carbon content. 
Plat 7009, which was kept bare, lost a HOT RES percentage 
of organic carbon in the first foot. 
The percentages of organic carbon in the second foot are 
