NORMAL SEASONAL CHANGES OF OXYGEN AND CARBON DIOXIDE PERCENTAGES IN GAS FROM THE LARGER PORES OF THREE ORCHARD SUBSOILS

Abstract

The seasonal changes in O2 and CO2 in the subsoil atmosphere of a sandy loam, a light silty clay loam, and a silty clay were studied at Ithaca, N. Y., from 1938 to 1942 inclusive. The study indicates that under the weather conditions in n.-e. U. S., O2 % in gas from heavy subsoils is normally low in the early spring and increases as the season advances. Under these conditions the minimum O2 level and the extent of the period of low O2 pressure seem to be detd. by accumulated precipitation, by soil texture and compaction, and by depth. CO2 % seems to fluctuate within a narrower range than O2, and seems, on the average, to reach max. levels during the summer months when soil temp. is relatively high, even though O2 % may be high at the same time.