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<br />Hillel, D., and Berliner, P., 1974, Waterproofing surface-zone sl,il aggregates for
<br />water conservation: Soil Science, v. 118, p. 131-135.
<br />Naturally occurring soil aggregates from the Mediterranean region of Cpper Galilee were
<br />treated with water-repellent sijcone to determine the effects upon infilttation and
<br />evaporation. Wben a soil surface was covered with a layer of these, mall (0.2-0.5mm), water
<br />repellent aggregates, infiltration was reduced. The largest (2-5rrcm) aggregates had the
<br />opposite effect, in that infiltrati.:>n increased. Aggregates remain,:d dryas water moved
<br />through interaggregate voids. Lager, water repellent aggregates w, re also found to reduce
<br />evaporation losses, in contrast to hydrophilic aggregates which appeared to have no
<br />signiE.cant effect.
<br />
<br />Holzhey, C.S., 1969a, Water-repellem soils in southern Califom.a, in DeBano, L.P.,
<br />and Letey, John, eds., Water-repellent soils: University ,}f California,
<br />Riverside, May 6-10,1968, Proceedings, p. 31-41.
<br />This ?aper provides a summary of the nature and distribution of water-repellent soils in
<br />southern California. The author differentiates between seasona and year-round water
<br />repellency. The former is chatacterized by water-repellent horizons immediately below
<br />decomposing woody litter. In this situation, repellency is most proliounced in dry soils, but
<br />breaks down when soils become moist in the winter. Repellency is then rees1:ablished upon
<br />drying. In contrast, soils that are seasonally water repellent are weft" ble wben extreme/)' dry, but
<br />become repellent following rain in the fall. The latter soils contain little or no woody plant
<br />litter. The author states that the type of repellency is related to the nature of the associated
<br />plant communities, which in turn reflects one of three climatic refimes (desert, mountain,
<br />and marine). The climatic patterns themselves also affect the expres ;ion of water repellency.
<br />Seasonal repellency is dominant in the lower elevations, while year-round repellency is found
<br />in mountain areas and mowltain-:.owland transitions. The paper includes a discussion on the
<br />distribution of water repellency a s determined by vegetation ty )e, along with a chatt
<br />depicting the relative water repellency of soils beneath various wood 1 species.
<br />
<br />Holzhey, C.S., 1969b, Soil morpholo~~cal relationships and wat,:r repellence, in
<br />DeBano, L.F., and Letey, John, eds., Water-repellent so:ls: Univ'~rsity of
<br />California, Riverside, May 6-10, 1968, Proceedings, p. 281-288.
<br />Water repellency in southern California soils is discussed with reS)ect to various physical
<br />attributes and soil morphologies. TILe author notes that herb-dominated communities
<br />primarily exhibit seasonal water repellency, whereas year round water repellency is often
<br />found in littered surface horizons with Ettered forest soil morphologes.
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