EFFECT OF DROP ENERGY AND SOIL AND WATER CHEMISTRY ON INFILTRATION AND EROSION

The effect of water salinity, soil sodicity, and raindrop energy on fi nal infiltration rate, wash erosion, and soil particle splash of two k aolinitic soils (ustochrepts and paleudalf) was studied. Final infiltr ation rate decreased with the increase in soil sodicity and drop energ y and increased with the increase of water salinity. Wash erosion and splash increased with the increase in soil sodicity and drop energy an d decreased with the increase in water salinity. Infiltration was very sensitive to relatively low drop energy. The major decrease in final infiltration rate was already achieved at drop energies lower than 10 J mm-1 m-2. Wash erosion increased exponentially with the increase in drop energy compared to a linear increase of the splash. Soil splash w as approximately 2-3 times higher than wash erosion for any given drop energy. The threshold energy for soil splash initiation was 4-6 J mm- 1 m-2, while for wash erosion (low exchangeable sodium percentage (ESP )) it was 2-4 J mm-1 m-2, and for the high ESP it was beyond the lowes t energy we used (2.1 J mm-1 m-2).