Effect of Bromus Inermis Shoot and Root on Soil and Water Conservation on the Slope

Experiment was carried out to plant Bromus inermis on the bare slope in Changping County, Beijing, and study effect of Bromus inermis shoot and root on soil and water loss on the slope. The results were the following that vegetation height and coverage were 84.7 cm and 89.6% after Bromus inermis planted for a year. And aboveground and underground biomasses in 0-30 cm soil were 5579.3 kg/hm(2) and 11732.5 kg/hm(2). Contributions of total Bromus inermis to runoff and sediment reduction were 95.2%-100.0%, which was significant for soil and water conservation. However, effect of Bromus inermis on soil and water conservation came true mainly though shoot and root, and contributions of root to runoff and sediment reduction were better than others of shoot. Contribution of shoot to surface runoff reduction was 0-22.8% under effective natural rainfall of 8.5-29.5 mm, and contribution to soil sediment reduction was only 0-0.1%. But contribution of root to surface runoff reduction was 77.2%-100.0% under the same rainfall, and contribution to soil sediment reduction was 99.9%-100.0%, which were better significantly than others of shoot. Furthermore, contributions of root to runoff and sediment reduction increased with rainfall decreasing.