Effects of contour grass hedges and micro-basins on soil and water loss on sloping croplands

Contour grass hedges and micro-basins have been proved to be very effective in reducing soil and water loss on sloping croplands in tropical and subtropical regions, however they have not been evaluated adequately in temperate regions and as a result they would not be accepted easily and widely by local farmers. Therefore in this research, the soil and water conservation effects of two native grass hedges and micro-basins were studied in temperate regions of northern China by simulated rainfall under different slope gradients (5, 10, 15 and 20%) and rainfall intensities (36 and 63 mm/h). The results showed that in the regions Pennisetum (Pennisetum alopecuroides (Linn.) Spreng.) hedges averagely decreased overland flow by 68% and soil loss by 79%; Correspondingly Arundinella (Arundinella hirta (Thunb.) C. Tanaka) hedges decreased overland flow by 55% and soil loss by 67%. In a second set of experiments, when Arundinella hedges were substituted with micro-basins, Pennisetum hedges decreased overland flow by 44% and soil loss by 83%, while micro-basins decreased overland flow by 70% and soil loss by 62%. These results indicate that contour grass hedges and micro-basins are very effective in the control of soil and water loss on sloping croplands in temperate regions, even though they did not result sufficient for a thorough protection under steep slope and intense rain conditions.