Rain energy and soil amendments effects on infiltration and erosion of three different soil types

The effect of rain kinetic energy and soil amendments on infiltration and erosion from three Israeli soils was studied using a drip-type simulator. The soil samples were from the top layer (0-250 mm depth) of cultivated fields differing in their texture, specific surface area and lime content. Three kinetic energies of raindrops were obtained by varying heights of fall (h = 0.4, 1-0 and 1.6 m) of 3 mm diameter drops. The soil types studied were Typic Chromoxerert, Typic Rhodoxeralf and Calcic Haploxeralf. Soil amendments were phosphogypsum (PG) and a combined application of an anionic polyacrylamide (PAM) with PG. An increase in the impact energy of the raindrops reduced depth of rain before ponding, final infiltration rate (FIR), cumulative infiltration (i.e. infiltration parameters) and increased soil erosion. The addition of PAM+PG to the soil surface significantly increased the infiltration parameters and reduced erosion compared with the PG and control treatments. The Typic Chromoxerert was the least susceptible of the three soils to sealing, probably because of its high smectitic clay content, high specific surface area and high CaCO3 content which stabilize soil structure. The Typic Rhodoxeralf with the lowest specific surface area was the most susceptible to clay dispersion, and seal formation. Relative to the Typic Chromoxerert and the Typic Rhodoxeralf, the Calcic Haploxeralf was intermediate in its susceptibility to seal formation.