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<br />Bond, R.D., and Harris, J .R., 1964, The influence of the microfl)fa on physical
<br />properties of soils.!. Effec:ts associated with filamentou! algae and fungi:
<br />Australian Journal of Soil Resl~arch, v. 2, p. 111-122.
<br />Contrary to some previous research, this investigation found evide: ICe that fungal activity
<br />tended to support the formation of water-stable soil aggregates. Th( paper also reported on
<br />other contributions of soil micro flora to structural characteristics. In reference to water
<br />repellency, research was still preLminarv and didn't appear to offer much new information.
<br />Results were inconclusive as to the specifIc source of fungal water tepellent substances, but
<br />the authors noted that basidiomycetes appeared to be signifIcant.
<br />
<br />Bozer, K.B., Brandt, G.H., and Hemwall,J.B., 1969, Chemistry ~fmaterials that
<br />make soils hydrophobic, lnn,eBano, L.F., and Letey,Jo:m, eds., 'Water-
<br />repellent soils: Univers:ity of California, Riverside, May ,,-10,1968,
<br />Proceedings, p. 189-204.
<br />This paper discusses some of the structural characteristics 0' various hydrophobic
<br />substances and their associated degree of water repellency. The au' hors state that many of
<br />the materials causing water [epeU~ncy in soils are made up of organi: compounds with both
<br />hydrophobic and hydrophilic characteristics. The permanence of w Iter repellency is related
<br />to the strength of the hydrophilic portion of the compound, since tI- is is the patt that bonds
<br />to soil particles. The hydrophobic portion of the molecule influences the degree of water
<br />repellency.
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<br />Brandt, G.H., 1969, Water movement in hydrophobic soils, in:C eBano, L.F., and
<br />Letey, John, eds., Wate!'-r'~pellent soils: University ofCdifornia,Riverside,
<br />May 6-10, 1968, Proceedings, p. 91-114.
<br />A series of water-flow experiments were performed on untreat,:d, medimn to coarse-
<br />textured soil cores, and on cores treated with a hydrophobic substance known as 4-t-butyl
<br />catechol (TBC). InfIltration into the cores was evaluated under 1 variety of conditions,
<br />including different heads, com:Ja,:tion rates, and soil textures. Results showed that
<br />equilibrium flow rates were reached more rapidly in treated (water. repellent) cores than in
<br />untreated ones. Although dry treated cores hindered water flow, in saturated, treated cores,
<br />flow was actually accelerated. To explain the observed effects or inf1ltration, the author
<br />proposed that TBC causes particles to "collect in small hydrophobic aggregates or bridges,"
<br />thus reducing additional pore plugging and stabilizing the matrix tc, water flow. This is in
<br />contrast to untreated cores, which allow both coarse and fine particl ~s to move duting water
<br />flow, and restrict permeability.
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