Shainberg, I., Inst of Soils & Water, The Volcanic Center, POB 6, Bet Dagan, Israel
Singer, M.J., Inst of Soils & Water, The Volcanic Center, POB 6, Bet Dagan, Israel

Constant intensity rain (40 mm h -1) with 3.2-mm drops falling from 0.25-, 0.90-, and 2.63-m heights and impact energies of 1.8, 7.6, and 18.6 kJ m -3, respectively, was used to produce seals on two soils in 55-mm deep by 82-mm diam acrylic cylinders. Soil exchangeable sodium percentage (ESP) was altered to ESP O (Ca-saturated soil), 5, and 10 before rain was applied. Infiltration rate (IR) and hydraulic conductivity (HC) of A horizon material from the Wyman (fine loamy, fixed, thermic, Mollic Haploxeralfs) soils decreased due to formation of soil seals as raindrop energy and ESP increased. The Wyo was more susceptible to sealing than Wyman despite its higher organic C content because of its higher clay content. Seal formation on Ca-soils (ESP O) increased gradually with increasing drop impact energy. Soils with ESP 5 and 10 were more susceptible to sealing at low energy rain than were ESP O soils. -from Authors