RUNOFF AND SOIL LOSS FROM STRIP CROPPED AND TERRACED HILLSIDE LANDS IN ST-LUCIA

Two soil conservation systems, comprising strip cropping and terracing, were designed and established for small-scale banana production on hillside lands in St Lucia. The systems were each installed on plots of approximately 0-8 ha, with an average slope of 20·. Rainfall, runoff and soil loss were measured from the plots during 24 storm events in the 1988 wet season. Generally, there was more runoff and soil loss from the strip cropped plot than from the terraced plot. For a maximum 20 min storm rainfall intensity of 44 mm/h, there was 50% more runoff, and 250% more soil loss from the strip cropped plot, than from the terraced plot. Runoff hydrographs were plotted and analysed. Runoff from the strip cropped plot showed sharper peaks, and a slower decline of the falling limb of the hydrographs. Results indicate that the terraced system was effective in minimizing runoff and soil loss. © 1993 Silsoe Research Institute.