Effects of Liquated Humic Substances on Runoff, Soil Losses by Runoff and by Splash under Artificial Rainfall Conditions

Soil, one of the most important natural resources, is lost by water and wind erosion. Addition of organic materials into the soils is commonly used for reducing soil and water losses. In this study liquated humic substances were applied at different doses (0, 5, 10, 20 and 40 ml l-1) to investigate its effects on runoff and soil losses caused by runoff and splash under artificial rainfall conditions on soil surface. Liquated humic substances were sprayed by a hand type pomp uniformly on the surface of the soil samples in the erosion pans (30 x 30 x 15 cm; at a slope of 9 %) and then simulated rainfall (40 mm h-1) was applied to these pans for 1 hour. The results indicated that, increases in humic substances doses reduced runoff (24-45 %), soil losses by runoff (7-97 %) and by splash (3-37 %), significantly (P < 0.01)