Field experiments were conducted uder rainfed conditions during rainy seasons of 1993 and 1994 on a 2.5 percent slopey Alfisol to study the effect of low cost technologies involving tillage practices and vegetative (Vetiver-Vetiveria zizanioides) barrier along with contour cultivation on soil and water conservation under castor crop. Vetiver grass planted on contours in June, 1988, at 1 m vertical drop which formed a dense continuous hedge was used as vegetative barrier in the study. Six treatments, viz., sowing on contour (T-1)(1) T-1 + vetiver (T-1)(1) T-1 + dead furrows (T-1)(1) T-1, + vetiver (T-1)(1) T-1 + ridges and furrows (T-1) and sowing along the slope (T-6-control) were tested in a R.B.D, with four replications in plots of 210 mn (6 x 35 m). Runoff was measured using multislot device for each runoff event in each plot. Soil loss was estimated from the samples drawn from the runoff water collected. There were eight runoff events in each year. Analysis of pooled data over two years indicated that runoff was highest (26.56 mm) in sowing along the slope (control) and lowest in sowing along the contour with ridges and furrows and vetiver barrier (2.98 mm). Similarly, soil loss was also highest (2.30 t ha(-1)) in sowing along the slope and lowest (0.18 t ha(-1)) in ridges and furrows with vetiver barrier. Ridges and furrows in combination with vetiver barrier resulted in a reduction of 88.78 and 92.17 percent in runoff and soil loss, respectively over control (sowing along the slope). The percent runoff was also lowest (1.51) in this treatment. Formation of dead furrows in combination with vetiver barrier was the next best treatment in reducing runoff and soil toss. The percent reduction in runoff and soil loss due to this treatment were 80.88 and 88.26, respectively when compared to control. The runoff and soil loss were considerably reduced in the treatments where vetiver barrier was included as a combination. The percent reduction in runoff was 66.03 in sowing along contour in combination with vetiver barrier and 56.99 in sowing along the contour with dead furrows in combination with vetiver barrier compared to the respective treatments without vetiver barrier. The percent reduction in soil loss was 76.14 in sowing along the contour with vetiver barrier and 70.97 in sowing along the contour with dead furrows in combination with vetiver barrier compared to the respective treatments without vetiver barrier. Considering the reduction in runoff and soil loss, sowing of castor on contours and formation of ridges and furrows in combination with vetiver barrier at 1 m vertical fall can be recommended as an effective practice for soil and water conservation in sloping Alfisols of Southern India.
