喀斯特石灰土水土保持剂的筛选

Screening of soil and water retaining agent for karst limestone soil

【目的】筛选出适合喀斯特石灰土的最佳水土保持剂,为喀斯特地区的石漠化治理重建提供参考依据。【方法】基于不同植物性材料水分吸收功能的差异,制备6种配方的水土保持剂,并在人工模拟降雨条件下进行喀斯特石灰土水土保持剂筛选试验。【结果】稻草比木糠(桉树)更有利于土壤物理结构改善,添加有稻草配方水土保持剂的土壤容重比空白对照处理(CK,未施用任何水土保持剂)约降低14.0%、总孔隙度约增大13.0%、最大持水量约增加31.0%。硅酸盐黏合剂能增加地表产流量,其中以单独施用硅酸盐黏合剂的累积产流量最高(3307 m L),极显著高于其他配方(P<0.01,下同),其地表产流量在降雨过程的各阶段也最高。6种配方的水土保持剂均能极显著减少土壤侵蚀,比CK分别降低了37.4%、26.1%、32.6%、47.5%、50.0%和55.9%。【结论】硅酸盐黏合剂、稻草和木糠配合使用能充分发挥出各自的土壤保持功能,且硅酸盐黏合剂、木糠(加适量甘油)、稻草(加适量甘油)按2∶1∶1比例进行配制的配方水土保持功能最强。

【Objective】The optimum soil and water retaining agent for limestone soil were screened out, in order to provide reference basis for control and reconstruction of rock-desertification in karst regions. 【Method 】Basing on water absorption capacity of plant materials, six kinds of soil and water retaining agents were prepared, then which were screened and tested under condition of rainfall simulation. 【Result】The results showed that, the rice straw was more conducive to improvement of soil phyical structure than wood chaff（eucalypt）, Using soil and water retaining agents containing rice straw, the soil bulk density was decreased by 14.0%, compared with blank control without soil and water retaining agent（CK）, and the total porosity and maximum water holding capacity（WHC） were increased by 13.0% and 31.0%, respectively.The Portland cement can increased supracrustal runoff yield particularly, the accumulated runoff yield using only Portland cement was the highest（3307 m L）, and extremely significantly higher than those of other formulas（P〈0.01,the same below）, and the supracrustal runoff yield at different stages was also the highest. Furthermore, six kinds of soil and water retaining agents could extremely significantly decrease soil erosion by 37.4%, 26.1%, 32.6%, 47.5%, 50.0% and 55.9%,respectively, compared with CK. 【Conclusion】Compounding Portland cement, wood chaff and rice straw can full play their soil and water retaining function, and glycerin is added to wood chaff and rice straw in advance, and their optimal ratio is