LYSIMETER EXPERIMENTS —II 75 
year except the first, and this increase averaged somewhat more than 
12 per cent for the five-years period. The calcium content therefore 
appears to be a better guide to the need of these soils for lime than does 
the lime requirement as determined by the Veitch method. The data 
at hand are too limited to admit of generalization, but they my be worth 
further consideration. 
Greater crop yield on the limed Volusia soil was accompanied by more 
nitrogen in the drainage water and also by more calcium. On the Dunkirk 
soil neither of these constituents was found in greater quantity in the 
drainage water from the limed tanks than from the unlimed. It may be 
remarked also that analyses of the soil air aspirated from the tanks, as 
reported in a previous publication, showed no appreciable difference 
between the limed and the unlimed Dunkirk soil, but in the Volusia soil 
the carbon-dioxide content of the soil air was much increased by liming. 
The fact that nitrate nitrogen in the drainage water and carbon dioxide 
in the soil air were present in larger amounts in the limed Volusia than in 
the unlimed gives evidence that decomposition of the organic matter pro- 
ceeded more rapidly when lime was applied to that soil. This, however, 
was not the case with the Dunkirk soil, and there is presented the rather 
unlooked-for situation in which lime increased decomposition of organic 
matter in one soil but did not do so in the other soil. 
A possible explanation for this divergent effect of lime on the two soils 
is suggested by the quantity of calcium in their respective drainage 
waters. As before stated, the application of lime had no effect on the 
> removal of calcium in the drainage water from the Dunkirk soil, but it 
increased markedly the quantity of calcium removed from the Volusia 
soil. It seems probable that by increasing the concentration of calcium in 
the soil water, the ammonifying, nitrifying, and other bacteria concerned 
in decomposition of organic matter were afforded a more congenial en- 
vironment. If liming did not increase the concentration of calcium in 
the soil water; as was -the case with the Dunkirk soil, there was no acceler- 
ation of decomposition. 
This experiment would seem to demonstrate one way in which liming 
may benefit soils. Certainly a larger amount of nitrate nitrogen was 
placed at the disposal of the plants, and the increased decomposition 
4 Bizzell, J. A.,and Lyon, T. L. The effect of certain factors on the carbon-dioxide content of soil air. 
Amer. Soc. ‘Agron. Journ, 10:97-112. 1918. 
