黄土丘陵沟壑区人工草地减沙水代价分析

以裸坡农地为对照，根据黄土丘陵沟壑区三大副区人工草地径流小区多年的观测资料，系统分析了黄土丘陵沟壑区人工草地减沙水代价（R_rs）特征及其与各影响因素之间的关系。结果表明:人工草地在不同地区其平均R_rs存在差异，且变化幅度较大，整体上丘陵沟壑第二副区大于第一副区和第三副区；不同牧草轮作下条播草木樨的R_rs最大，较自然草坡高25%，其R_rs表现为:条播草木樨 > 撒播苜蓿 > 草木樨 > 苜蓿 > 自然草坡；草田带状间轮作的R_rs表现为:草木樨/农作物 > 苜蓿/农作物，且草田带状间轮作的R_rs明显高于牧草轮作；人工草地R_rs与汛期降水量、侵蚀模数呈较好的指数反比关系，与最大30 min降雨强度（I₃₀）呈线性反比关系。

Cost for Runoff and Sediment Control of Artificial Grassland at the Plot Scale in the Loess Hill and Gully Region

The study was conducted to compare cost for water and sediment control (R_rs) of different artificial grasses based on perennially monitoring data of loess hill and gully region and the bare slope set as control. And then the characteristics of R_rs of artificial grass and the relations among various influence factors were systematically analyzed. The results showed that the average R_rs of the artificial grass were different in different regions and had large differences, the average R_rs of the artificial grass of the second sub-region of hill and gully area of the Loess Plateau is greater than the first and the third sub-regions; for different forage managements, R_rs of sweet clover rotation is 25% greater than that of the natural grass slope. The R_rs of forages decreased in the order: drilling Melilotus suaveolwna > broadcasting Medicago sativa > Melilotus suaveolwna > Medicago sativa > slope with natural grass. The R_rs of grass rotation decreased in the order: Melilotus suaveolwna > Medicago sativa and it was bigger than that of forage rotation; the R_rs of artificial grass and precipitation, soil erosion modulus presented the inverse exponential correlations, R_rs of grass measures and I₃₀ showed the good inversely linear relationship.