chresard

noun

1. (dated)The portion of the water in a sample of soil that is available to vegetation (e.g. plant roots)

   “As in the previous series the chresard decreased progressively with the density, but the correspondence with depth was less consistent.”

   “The soil is typically light and sandy, and the oaks are relicts from a moist phase of the climatic cycle that have been able to maintain themselves against the competition of the grasses by virtue of the favored chresard of the sandy soil.”