STONE-COVER AND RAIN INTENSITY - EFFECTS ON INFILTRATION, EROSION AND WATER SPLASH

The effects of level of stone cover, stone size and rain intensity on infiltration, erosion and water splash from a silty loam soil (Calcic Haploxeralf) were studied using a laboratory rainfall simulator. Square asbestos cement plates (5 mm thick), measuring 100 and 2500 mm2, were used to simulate stones. Three levels of surface cover (0, 25 and 50% cover) and two rain intensities (21 and 45 mm h-1) were studied. An increase in the level of stone cover increased infiltration and reduced erosion. The size of the asbestos cement plates had no effect on either infiltration or erosion. An increase in rainfall intensity resulted in a moderate increase in infiltration and a significant increase in soil erosion. Water splash from bare soil (control) reached 15.9% of the applied rain, thereby signifying its importance in simulated rainfall studies. An increase in the level of stone cover reduced water splash. By mulching with small plates, a lower percentage of water splash occurred, compared with large plates and the control. Rain intensity had no effect on water splash.