黔中喀斯特山区坡耕地产流产沙对无籽刺梨种植的响应

产流产沙是坡耕地土壤侵蚀的主要形式,为探讨无籽刺梨对黔中喀斯特山区坡耕地土壤侵蚀治理效应,采用径流小区野外定位观测法和相关性分析法,分析了坡度15°和25°坡耕地共6个自然坡面径流小区2016年6—9月15次野外实测侵蚀性降雨产流产沙数据。结果表明:(1)在同坡度同降雨量同I₃₀下,无籽刺梨地较自然恢复地有显著保水保沙能力,无籽刺梨+自然荒草地模式优于无籽刺梨单种模式。(2)无籽刺梨种植模式减流减沙效果坡度25°优于15°,减沙效果优于减流效果。其中无籽刺梨+自然荒草地减流减沙效果最优,在小雨、中雨、大雨、暴雨4种雨型下,坡度15°度时较自然恢复地分别平均减流59.08%,65.23%,56.96%,54.87%,分别平均减沙87.32%,71.64%,51.10%,74.69%;坡度25°度时分别平均减流53.11%,76.09%,76.72%,46.12%,分别平均减沙85.40%,86.87%,71.55%,73.99%。(3)研究区产流产沙量与降雨参数(P、I₃₀)高度相关且在0.01水平上显著,在不同雨型下无籽刺梨减流减沙均有明显效果,小雨、中雨时减流减沙效果最佳。研究证实了研究区无籽刺梨种植能抵御不同雨型的降雨侵蚀,可作为贵州省喀斯特山区生态修复的极优经济选种。

Response of Runoff and Sediment Yield of Sloping Farmland to Rosa sterilis S. D. ShiPlanting in Karst Mountainous Area of Central Guizhou

Runoff and sediment yield is the main form of soil erosion in sloping farmland. In order to explore the soil and water conservation benefit of Rosa sterilis S. D. Shi on slope farmland in karst mountainous area of central Guizhou, using field location observation method in runoff plot and correlation analysis method, this study analyzed the field measured data of runoff and sediment under six natural runoff plots, which were natural restoration land (NRL), R. sterilis S. D. Shi land (RSSDSL), R. sterilis S. D. Shi + natural grassland (RSSDSL+NGL),on 15ånd 25° slope under 15 erosive rainfalls from June to September 2016. The results showed that:(1) Under the same slope, rainfall and maximum 30 min rainfall intensity(I₃₀), the RSSDSL had better water and sediment retention ability than NRL, and RSSDSL+NGL pattern was better than the single RSSDSL pattern.(2) The runoff and sediment reduction effect of R. sterilis S. D. Shi planting pattern with a slope of 25° was better than that of 15°, and the sediment reduction effect was better than runoff reduction. The RSSDSL+NGL had the best runoff and sediment reduction effect. Under the four rain types of light rain, moderate rain, heavy rain and rainstorm, when the slope was 15°, compared with NRL, the average runoff reduction of RSSDSL+NGL were 59.08%, 65.23%, 56.96% and 54.87%, respectively, and the average sediment reduction were 87.32%, 71.64%, 51.10% and 74.69%, respectively. While, when the slope was 25°, the average runoff of reduction were 53.11%, 76.09%, 76.72% and 46.12%, respectively, and the average sediment reduction were 85.40%, 86.87%, 71.55% and 73.99%, respectively. (3) Runoff and sediment yield in the study area was highly correlated with rainfall parameters (P, I₃₀) and was significant at the 0.01 level. R. sterilis S. D. Shi had obvious effect on runoff and sediment reduction under different rain types, and the best effect was achieved in light rain and moderate rain. In conclusion, R. sterilis S. D. Shi planting in the study area could effectively control the rainfall erosion of all rain types, and could be used as an excellent economic choice for ecological restoration in karst mountainous areas of Guizhou Province.