SOIL EROSION BY HAND TOOLS FOR SMALL-SCALE TILLAGE ON HILLSLOPES ASSESSED THROUGH THE UNIVERSAL SOIL LOSS EQUATION

The objective of this study was to evaluate and compare the erosion rates generated by two types of hand tools for small-scale tillage on a hillslope, using experimental tests and the Universal Soil Loss Equation (USLE). The hand tools evaluated were a conventional hoe and a redesigned furrowing hoe. The experimental work was conducted in a 145 m(2) plot with an average slope of 45% in Colombia. Three treatments were evaluated: a) Zero tillage and no herbicide (control); b) tillage with a conventional hoe plus herbicide; c) tillage with a furrowing hoe plus herbicide. Each treatment was represented by a sedimentation plot, using three repetitions in blocks (lower, middle, and upper parts of each plot), according to the maximum slope gradient. Both hand tillage tools generated high to extremely high erosion rates with differences of up to 8.1 times between them. Both types of tools accelerated soil erosion rates, being higher in furrowing hoe tillage. The USLE method showed no differences in erosion rates between the tillage methods, while differences were found in the experimental tests. This is explained by the lower sensitivity of the USLE to detect small-scale changes in factors such as soil type, cover, and slope.