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<br />
<br />Session VI - Natmal C~.u!les of Water Repellency in Soil,:
<br />*Bond, R.D. Factors responsible for water repellence of soil~
<br />*DeBano, L.F. The relationship between heat treatment and water repellency in
<br />soils.
<br />*Holzhey, C.S. Soil morphologkal relationships and water repellence.
<br />Adams, Susan, Sttain, B.R., and Adams, M.S. Water-repellen: soils and annual plant
<br />cover in a desert scmb comrnur~ty of southeastern Califoro.ia
<br />
<br />Session VII - The Effect of Soil Water Repellency and Wetting Agents on
<br />Plant Growth:
<br />Osborn, J.F. The effect of wetting agents and water repellency on the germination
<br />and establishment of gras~;.
<br />Parr,].F. Effects of surfactmts on plant growth and conside cations in their use.
<br />Endo, R.M. The deleteriom effects of two nonionic surfacta lts on the germination
<br />and growth of various grasses.
<br />Shaw, E. Molecular physics and related properties of water ill connection with
<br />phenomena of wetti::lg.
<br />Waddington, D.V. Observations of water repellency on turffrass areas.
<br />
<br />DeBano, L.F., Mann, L.D., and Hamilton, D.A., 1970, Translocation of hydrophobic
<br />substances into soil by burning organic litter: Soil Scien:e Society of America
<br />Proceedings, v. 34, p. 130-133.
<br />Researchers investigated the relalionships between soil texture, sur 'ace material, and heat-
<br />induced water repellency. Four different soil types were evaluated in burning experiments
<br />with two different surface materials (sugarbush plant litter, and a water-repeu,ent soil). The
<br />soils that were tested included a pure sand, and three samples with v uying amounts of sand,
<br />silt (12-42%) and clay (1-130/0. Researchers observed that hydrophobic substances
<br />translated down into the so~. during burning and formed water-repeU ent layers. The thickest
<br />and most intense layers occurred under conditions of burned litter a~ plant top material, and
<br />with pure sand as the underlying soil. The results are attributed to he fact that the coarse-
<br />textured soils had a smaller surface area to volume ratio. The auth, )rs also noted a general
<br />increase in water repellency with an increase in translated organic matter, but no direct
<br />relationship was found.
<br />
<br />DeBano, L.F., and Rice, R.M., 1973, Water-repellent soils- theiJ implication in
<br />forestry: Journal of Fort,stry, v. 71, p. 220-223.
<br />This paper offers an extensive semmary of information on wat~r-repellent soils (both
<br />biologically and fire-induced), and provides a good base of info:mation on the causes,
<br />effects, characteristics, and r.he interdependence of various factors. Although more current
<br />research has since added to the findings presented in this paper, it is still a comprehensive
<br />account of previous research on the topic. The authors do, howe /er, neglect to mention
<br />some alternative hypotheses regarding the mechanism of formation :e.g. Savage, et al., 1969
<br />and 1972).
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