淤地坝对坡地土壤有机碳分布的影响

Effect of Check-dam on Distribution of Soil Organic Carbon in Slope Land

以六道沟流域的淤地坝为例，测定了坝内外坡地土壤有机碳含量，旨在探讨淤地坝对坡地土壤有机碳分布的影响。研究结果表明：淤积达20年的淤地坝可以显著增加10m长坡面0～130cm土层的土壤有机碳含量，尤其表层有机碳含量增加了2．92g/kg，较坡外增加358．34％，差异极显著（P〈0．01）；从坝外到坝内坡地土壤有机碳基本表现出线性增大的趋势，但极大值点出现在坝内靠近分界线处；淤地坝的存在使坝内坡地比坝外坡地相同坡位的有机碳含量均增大，上坡增加的最大，达117．36％；坝内坡地土壤有机碳含量的变异系数较坝外的大。

In order to explore the effect of check-dam on the distribution of soil organic carbon （SOC） in slope land, the author tested the SOC content in the slope land inside and outside check-dam of the Liudaogou basin. The results showed that the check-dam, which was built 20 years ago, could significantly increase the content of SOC in 0- 130-cm-deep soil layer of 10-m -long inside slope land, especially the SOC content in surface soil layer was increased by 2.92 g/kg or 358.34%, which was very significantly different from that in surface soil layer of outside slope land （P〈0.01）. Basically, the SOC content in slope land exhibited a linear increasing trend from the outside to inside of check-dam, but the maximum value appeared near the boundary of inside dam. The existence of check-dam caused that the inside slope land had more SOC content than the outside one in the same slope position, and the biggest increase rate （ 117.36% ） of SOC content was found in upslope position. The variation coefficient of SOC content in inside slope land was higher than that in outside one.