The total water available to roots is partly dependent on soil depth. The deep Hagerstown soils (fig. 18) have the capacity to store more water than Leck Kill soils simply because Hagerstown soils are deeper. The curves show a trend toward less available water at a depth of about 50 centimeters (20 inches), where clay content tends to be highest and organic matter content is low. Coarse silt and very fine sand content of soils are positively correlated with available moisture capacity. The Leek Kill soil is droughty, because it contains only one-third as much water storage in the upper 30 centimeters (12 inches) as Hagerstown soils and, in addition, has greater coarse fragment content and less depth. Should Hagerstown soils become moistened to field capacity, plants rooting to a depth of 10 feet would have more than 10 inches of available water to extract.

10/15/98