论文部分内容阅读
Based on field runoff plots observation and sample analysis,the effect of slope gradient on soil organic carbon loss was studied under natural rainfall conditions in loess hilly region. The results showed that with slope gradient increasing(from10° to 30°) ,the changing trend of soil erosion intensity(A) was A20°>A30°>A 15°>A10°>A25°,suggesting that slope gradient between 20° and 25° was a critical degree ranger to exist. Soil organic car-bon loss was mainly influenced by soil erosion intensity,appearing the same trend as did soil erosion intensity with increasing slope gradient. Soil erosion results in organic carbon enrichment in sediment. Average enrichment ratios of five runoff plots varied from 2.27 to 3.74,and decreased with increasing erosion intensity and slope gradient. The decrease of surface runoff and soil erosion is the key to reduce soil organic carbon loss.
Based on field runoff plots observation and sample analysis, the effect of slope gradient on soil organic carbon loss was studied under natural rainfall conditions in loess hilly region. The results showed that with slope gradient increasing (from 10 ° to 30 °), the changing trend Soil erosion intensity (A) was A20 °> A30 °> A 15 °> A10 °> A25 °, suggesting that slope gradient between 20 ° and 25 ° was a critical degree range to to. Soil organic car-bon loss was mainly influenced by soil erosion intensity, appearing the same trend as did soil erosion intensity with increasing slope gradient. soil erosion results in organic carbon enrichment in sediment. average enrichment ratios of five runoff plots varied from 2.27 to 3.74, and decreased with increasing erosion intensity and slope gradient. The decrease of surface runoff and soil erosion is the key to reduce soil organic carbon loss.