DETERMINATION OF HYDROLOGIC POTENTIAL IN T3-TYPE TEPETATES WITH SIMULATED RAINFALL

Abstract

Several researchers have found that tepetates are more erodible when managed under an agricultural system, because they become more susceptible to the erosive process. For this reason it is necessary to know their hydrologic potential, and its ability to remove and transport sediments. Using a rainfall simulator on a T3-type tepetate, an experiment was conducted to determine its hydrologic potential, under three conditions: natural tepetate (TN) (control), subsoiling tepetate (TRR) and tilled tepetate (TI); and two rainfall intensities: 40 and 60 mm h-1 in humid and dry conditions. The results were related to sediment yield. The control (TN) resulted in higher soil losses. Poinding times in TN and TI treatments were less at the intensity of 60 mm h-1, whereas the TRR treatment presented a higher water infiltration capacity. Overall, the TN treatment presented the highest percentage of runoff and the lowest water retention capacity; therefore, this condition has a high hydrologic potential to generate runoff. TI and TRR presented moderately high and moderately low hydrologic potentials, respectively. In addition, it was confirmed that the T3- type tepetates are highly erodible.