SOIL DRAINAGE CLASSES AND SOIL WATER TABLE RELATIONS IN MEDIUM AND COARSE TEXTURED SOILS IN SOUTHERN ONTARIO

Abstract

Water table levels were recorded for up to 5 yr on five soil catenas, each containing a well, imperfectly, poorly and very poorly drained member. Water table measurements in combination with soil morphology were used to establish the zone of free water saturation and from this, periods of saturation were recorded at pre-determined depths or, alternatively, mean high water table and mean low water table levels were calculated for the periods 1 Jan.–31 Dec. and 1 May–31 Oct. Periods of saturation for well/imperfectly and imperfectly/very poorly drained soils were significantly different at the.2 level of probability, but there was no significant difference between the imperfectly/poorly or poorly/very poorly drained members. At the.05 level of probability, only two drainage classes were significantly different. The large within -class variability raises some conern over relying on soil morphology to determine water table characteristics and as well, questions the usefulness of soil drainage classes as currently defined. The significance of the data is discussed in relation to soil mapping, tile drainage and septic tank disposal of wastes.